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Merge branch 'master' into duplicate_key

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Andrey Rahmatullin 2021-06-14 18:45:33 +05:00 committed by GitHub
parent 1d77eac950 9f81de2a50
commit 16be658a31
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352 changed files with 18228 additions and 7868 deletions
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2
.bumpversion.cfg
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@ -1,5 +1,5 @@
[bumpversion]
current_version = 2.0.0
current_version = 2.5.0
commit = True
tag = True
tag_name = {new_version}

19
.flake8 Normal file
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@ -0,0 +1,19 @@
[flake8]
max-line-length = 119
ignore = W503
exclude =
# Exclude files that are meant to provide top-level imports
# E402: Module level import not at top of file
# F401: Module imported but unused
scrapy/__init__.py E402
scrapy/core/downloader/handlers/http.py F401
scrapy/http/__init__.py F401
scrapy/linkextractors/__init__.py E402 F401
scrapy/selector/__init__.py F401
scrapy/spiders/__init__.py E402 F401
# Issues pending a review:
scrapy/utils/url.py F403 F405
tests/test_loader.py E741

1
.gitattributes vendored Normal file
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@ -0,0 +1 @@
tests/sample_data/** binary

40
.github/workflows/checks.yml vendored Normal file
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@ -0,0 +1,40 @@
name: Checks
on: [push, pull_request]
jobs:
checks:
runs-on: ubuntu-18.04
strategy:
matrix:
include:
- python-version: 3.9
env:
TOXENV: security
- python-version: 3.9
env:
TOXENV: flake8
# Pylint requires installing reppy, which does not support Python 3.9
# https://github.com/seomoz/reppy/issues/122
- python-version: 3.8
env:
TOXENV: pylint
- python-version: 3.9
env:
TOXENV: typing
- python-version: 3.8 # Keep in sync with .readthedocs.yml
env:
TOXENV: docs
steps:
- uses: actions/checkout@v2
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@v2
with:
python-version: ${{ matrix.python-version }}
- name: Run check
env: ${{ matrix.env }}
run: |
pip install -U tox
tox

31
.github/workflows/publish.yml vendored Normal file
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@ -0,0 +1,31 @@
name: Publish
on: [push]
jobs:
publish:
runs-on: ubuntu-18.04
if: startsWith(github.event.ref, 'refs/tags/')
steps:
- uses: actions/checkout@v2
- name: Set up Python 3.9
uses: actions/setup-python@v2
with:
python-version: 3.9
- name: Check Tag
id: check-release-tag
run: |
if [[ ${{ github.event.ref }} =~ ^refs/tags/[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$ ]]; then
echo ::set-output name=release_tag::true
fi
- name: Publish to PyPI
if: steps.check-release-tag.outputs.release_tag == 'true'
run: |
pip install --upgrade setuptools wheel twine
python setup.py sdist bdist_wheel
export TWINE_USERNAME=__token__
export TWINE_PASSWORD=${{ secrets.PYPI_TOKEN }}
twine upload dist/*

25
.github/workflows/tests-macos.yml vendored Normal file
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@ -0,0 +1,25 @@
name: macOS
on: [push, pull_request]
jobs:
tests:
runs-on: macos-10.15
strategy:
matrix:
python-version: [3.6, 3.7, 3.8, 3.9]
steps:
- uses: actions/checkout@v2
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@v2
with:
python-version: ${{ matrix.python-version }}
- name: Run tests
run: |
pip install -U tox
tox -e py
- name: Upload coverage report
run: bash <(curl -s https://codecov.io/bash)

74
.github/workflows/tests-ubuntu.yml vendored Normal file
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@ -0,0 +1,74 @@
name: Ubuntu
on: [push, pull_request]
jobs:
tests:
runs-on: ubuntu-18.04
strategy:
matrix:
include:
- python-version: 3.7
env:
TOXENV: py
- python-version: 3.8
env:
TOXENV: py
- python-version: 3.9
env:
TOXENV: py
- python-version: pypy3
env:
TOXENV: pypy3
PYPY_VERSION: 3.6-v7.3.1
# pinned deps
- python-version: 3.6.12
env:
TOXENV: pinned
- python-version: 3.6.12
env:
TOXENV: asyncio-pinned
- python-version: pypy3
env:
TOXENV: pypy3-pinned
PYPY_VERSION: 3.6-v7.2.0
# extras
# extra-deps includes reppy, which does not support Python 3.9
# https://github.com/seomoz/reppy/issues/122
- python-version: 3.8
env:
TOXENV: extra-deps
- python-version: 3.9
env:
TOXENV: asyncio
steps:
- uses: actions/checkout@v2
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@v2
with:
python-version: ${{ matrix.python-version }}
- name: Install system libraries
if: matrix.python-version == 'pypy3' || contains(matrix.env.TOXENV, 'pinned')
run: |
sudo apt-get update
sudo apt-get install libxml2-dev libxslt-dev
- name: Run tests
env: ${{ matrix.env }}
run: |
if [[ ! -z "$PYPY_VERSION" ]]; then
export PYPY_VERSION="pypy$PYPY_VERSION-linux64"
wget "https://downloads.python.org/pypy/${PYPY_VERSION}.tar.bz2"
tar -jxf ${PYPY_VERSION}.tar.bz2
$PYPY_VERSION/bin/pypy3 -m venv "$HOME/virtualenvs/$PYPY_VERSION"
source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
fi
pip install -U tox
tox
- name: Upload coverage report
run: bash <(curl -s https://codecov.io/bash)

36
.github/workflows/tests-windows.yml vendored Normal file
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@ -0,0 +1,36 @@
name: Windows
on: [push, pull_request]
jobs:
tests:
runs-on: windows-latest
strategy:
matrix:
include:
- python-version: 3.6
env:
TOXENV: windows-pinned
- python-version: 3.7
env:
TOXENV: py
- python-version: 3.8
env:
TOXENV: py
# https://twistedmatrix.com/trac/ticket/9990
#- python-version: 3.9
#env:
#TOXENV: py
steps:
- uses: actions/checkout@v2
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@v2
with:
python-version: ${{ matrix.python-version }}
- name: Run tests
env: ${{ matrix.env }}
run: |
pip install -U tox
tox

5
.gitignore vendored
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@ -14,7 +14,12 @@ htmlcov/
.coverage
.pytest_cache/
.coverage.*
coverage.*
test-output.*
.cache/
.mypy_cache/
/tests/keys/localhost.crt
/tests/keys/localhost.key
# Windows
Thumbs.db

7
.readthedocs.yml
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@ -1,11 +1,16 @@
version: 2
formats: all
sphinx:
configuration: docs/conf.py
fail_on_warning: true
build:
image: latest
python:
# For available versions, see:
# https://docs.readthedocs.io/en/stable/config-file/v2.html#build-image
version: 3.7 # Keep in sync with .travis.yml
version: 3.8 # Keep in sync with .github/workflows/checks.yml
install:
- requirements: docs/requirements.txt
- path: .

65
.travis.yml
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@ -1,65 +0,0 @@
language: python
dist: xenial
branches:
only:
- master
- /^\d\.\d+$/
- /^\d\.\d+\.\d+(rc\d+|\.dev\d+)?$/
matrix:
include:
- env: TOXENV=security
python: 3.8
- env: TOXENV=flake8
python: 3.8
- env: TOXENV=pypy3
- env: TOXENV=py35
python: 3.5
- env: TOXENV=pinned
python: 3.5
- env: TOXENV=py35-asyncio
python: 3.5.2
- env: TOXENV=py36
python: 3.6
- env: TOXENV=py37
python: 3.7
- env: TOXENV=py38
python: 3.8
- env: TOXENV=extra-deps
python: 3.8
- env: TOXENV=py38-asyncio
python: 3.8
- env: TOXENV=docs
python: 3.7 # Keep in sync with .readthedocs.yml
install:
- |
if [ "$TOXENV" = "pypy3" ]; then
export PYPY_VERSION="pypy3.5-5.9-beta-linux_x86_64-portable"
wget "https://bitbucket.org/squeaky/portable-pypy/downloads/${PYPY_VERSION}.tar.bz2"
tar -jxf ${PYPY_VERSION}.tar.bz2
virtualenv --python="$PYPY_VERSION/bin/pypy3" "$HOME/virtualenvs/$PYPY_VERSION"
source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
fi
- pip install -U tox twine wheel codecov
script: tox
after_success:
- codecov
notifications:
irc:
use_notice: true
skip_join: true
channels:
- irc.freenode.org#scrapy
cache:
directories:
- $HOME/.cache/pip
deploy:
provider: pypi
distributions: "sdist bdist_wheel"
user: scrapy
password:
secure: JaAKcy1AXWXDK3LXdjOtKyaVPCSFoCGCnW15g4f65E/8Fsi9ZzDfmBa4Equs3IQb/vs/if2SVrzJSr7arN7r9Z38Iv1mUXHkFAyA3Ym8mThfABBzzcUWEQhIHrCX0Tdlx9wQkkhs+PZhorlmRS4gg5s6DzPaeA2g8SCgmlRmFfA=
on:
tags: true
repo: scrapy/scrapy
condition: "$TOXENV == py37 && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$"

4
AUTHORS
View File

@ -1,8 +1,8 @@
Scrapy was brought to life by Shane Evans while hacking a scraping framework
prototype for Mydeco (mydeco.com). It soon became maintained, extended and
improved by Insophia (insophia.com), with the initial sponsorship of Mydeco to
bootstrap the project. In mid-2011, Scrapinghub became the new official
maintainer.
bootstrap the project. In mid-2011, Scrapinghub (now Zyte) became the new
official maintainer.
Here is the list of the primary authors & contributors:

5
CODE_OF_CONDUCT.md
View File

@ -55,7 +55,7 @@ further defined and clarified by project maintainers.
## Enforcement
Instances of abusive, harassing, or otherwise unacceptable behavior may be
reported by contacting the project team at opensource@scrapinghub.com. All
reported by contacting the project team at opensource@zyte.com. All
complaints will be reviewed and investigated and will result in a response that
is deemed necessary and appropriate to the circumstances. The project team is
obligated to maintain confidentiality with regard to the reporter of an incident.
@ -72,3 +72,6 @@ available at [http://contributor-covenant.org/version/1/4][version].
[homepage]: http://contributor-covenant.org
[version]: http://contributor-covenant.org/version/1/4/
For answers to common questions about this code of conduct, see
https://www.contributor-covenant.org/faq

25
README.rst
View File

@ -10,9 +10,17 @@ Scrapy
:target: https://pypi.python.org/pypi/Scrapy
:alt: Supported Python Versions
.. image:: https://img.shields.io/travis/scrapy/scrapy/master.svg
:target: https://travis-ci.org/scrapy/scrapy
:alt: Build Status
.. image:: https://github.com/scrapy/scrapy/workflows/Ubuntu/badge.svg
:target: https://github.com/scrapy/scrapy/actions?query=workflow%3AUbuntu
:alt: Ubuntu
.. image:: https://github.com/scrapy/scrapy/workflows/macOS/badge.svg
:target: https://github.com/scrapy/scrapy/actions?query=workflow%3AmacOS
:alt: macOS
.. image:: https://github.com/scrapy/scrapy/workflows/Windows/badge.svg
:target: https://github.com/scrapy/scrapy/actions?query=workflow%3AWindows
:alt: Windows
.. image:: https://img.shields.io/badge/wheel-yes-brightgreen.svg
:target: https://pypi.python.org/pypi/Scrapy
@ -34,13 +42,20 @@ Scrapy is a fast high-level web crawling and web scraping framework, used to
crawl websites and extract structured data from their pages. It can be used for
a wide range of purposes, from data mining to monitoring and automated testing.
Scrapy is maintained by Zyte_ (formerly Scrapinghub) and `many other
contributors`_.
.. _many other contributors: https://github.com/scrapy/scrapy/graphs/contributors
.. _Zyte: https://www.zyte.com/
Check the Scrapy homepage at https://scrapy.org for more information,
including a list of features.
Requirements
============
* Python 3.5+
* Python 3.6+
* Works on Linux, Windows, macOS, BSD
Install
@ -81,7 +96,7 @@ Please note that this project is released with a Contributor Code of Conduct
(see https://github.com/scrapy/scrapy/blob/master/CODE_OF_CONDUCT.md).
By participating in this project you agree to abide by its terms.
Please report unacceptable behavior to opensource@scrapinghub.com.
Please report unacceptable behavior to opensource@zyte.com.
Companies using Scrapy
======================

25
appveyor.yml
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@ -1,25 +0,0 @@
platform: x86
version: '{branch}-{build}'
environment:
matrix:
- PYTHON: "C:\\Python36"
TOX_ENV: py36
branches:
only:
- master
- /d+\.\d+\.\d+[\w\-]*$/
install:
- "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
- "SET PYTHONPATH=%APPVEYOR_BUILD_FOLDER%"
- "SET TOX_TESTENV_PASSENV=HOME HOMEDRIVE HOMEPATH PYTHONPATH USERPROFILE"
- "pip install -U tox"
build: false
skip_tags: true
test_script:
- "tox -e %TOX_ENV%"
cache:
- '%LOCALAPPDATA%\pip\cache'

43
conftest.py
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@ -1,6 +1,11 @@
from pathlib import Path
import pytest
from twisted.web.http import H2_ENABLED
from scrapy.utils.reactor import install_reactor
from tests.keys import generate_keys
def _py_files(folder):
@ -12,14 +17,23 @@ collect_ignore = [
"scrapy/utils/testsite.py",
# contains scripts to be run by tests/test_crawler.py::CrawlerProcessSubprocess
*_py_files("tests/CrawlerProcess"),
# Py36-only parts of respective tests
*_py_files("tests/py36"),
# contains scripts to be run by tests/test_crawler.py::CrawlerRunnerSubprocess
*_py_files("tests/CrawlerRunner"),
]
for line in open('tests/ignores.txt'):
file_path = line.strip()
if file_path and file_path[0] != '#':
collect_ignore.append(file_path)
with open('tests/ignores.txt') as reader:
for line in reader:
file_path = line.strip()
if file_path and file_path[0] != '#':
collect_ignore.append(file_path)
if not H2_ENABLED:
collect_ignore.extend(
(
'scrapy/core/downloader/handlers/http2.py',
*_py_files("scrapy/core/http2"),
)
)
@pytest.fixture()
@ -38,6 +52,14 @@ def pytest_collection_modifyitems(session, config, items):
pass
def pytest_addoption(parser):
parser.addoption(
"--reactor",
default="default",
choices=["default", "asyncio"],
)
@pytest.fixture(scope='class')
def reactor_pytest(request):
if not request.cls:
@ -51,3 +73,12 @@ def reactor_pytest(request):
def only_asyncio(request, reactor_pytest):
if request.node.get_closest_marker('only_asyncio') and reactor_pytest != 'asyncio':
pytest.skip('This test is only run with --reactor=asyncio')
def pytest_configure(config):
if config.getoption("--reactor") == "asyncio":
install_reactor("twisted.internet.asyncioreactor.AsyncioSelectorReactor")
# Generate localhost certificate files, needed by some tests
generate_keys()

2
docs/Makefile
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@ -8,7 +8,7 @@ PYTHON = python
SPHINXOPTS =
PAPER =
SOURCES =
SHELL = /bin/bash
SHELL = /usr/bin/env bash
ALLSPHINXOPTS = -b $(BUILDER) -d build/doctrees \
-D latex_elements.papersize=$(PAPER) \

9
docs/README.rst
View File

@ -57,3 +57,12 @@ There is a way to recreate the doc automatically when you make changes, you
need to install watchdog (``pip install watchdog``) and then use::
make watch
Alternative method using tox
----------------------------
To compile the documentation to HTML run the following command::
tox -e docs
Documentation will be generated (in HTML format) inside the ``.tox/docs/tmp/html`` dir.

2
docs/_ext/scrapydocs.py
View File

@ -17,7 +17,7 @@ class SettingsListDirective(Directive):
def is_setting_index(node):
if node.tagname == 'index':
# index entries for setting directives look like:
# [(u'pair', u'SETTING_NAME; setting', u'std:setting-SETTING_NAME', '')]
# [('pair', 'SETTING_NAME; setting', 'std:setting-SETTING_NAME', '')]
entry_type, info, refid = node['entries'][0][:3]
return entry_type == 'pair' and info.endswith('; setting')
return False

10
docs/_static/custom.css vendored Normal file
View File

@ -0,0 +1,10 @@
/* Move lists closer to their introducing paragraph */
.rst-content .section ol p, .rst-content .section ul p {
margin-bottom: 0px;
}
.rst-content p + ol, .rst-content p + ul {
margin-top: -18px; /* Compensates margin-top: 24px of p */
}
.rst-content dl p + ol, .rst-content dl p + ul {
margin-top: -6px; /* Compensates margin-top: 12px of p */
}

7
docs/_templates/layout.html vendored
View File

@ -3,14 +3,9 @@
{% block footer %}
{{ super() }}
<script type="text/javascript">
!function(){var analytics=window.analytics=window.analytics||[];if(!analytics.initialize)if(analytics.invoked)window.console&&console.error&&console.error("Segment snippet included twice.");else{analytics.invoked=!0;analytics.methods=["trackSubmit","trackClick","trackLink","trackForm","pageview","identify","reset","group","track","ready","alias","page","once","off","on"];analytics.factory=function(t){return function(){var e=Array.prototype.slice.call(arguments);e.unshift(t);analytics.push(e);return analytics}};for(var t=0;t<analytics.methods.length;t++){var e=analytics.methods[t];analytics[e]=analytics.factory(e)}analytics.load=function(t){var e=document.createElement("script");e.type="text/javascript";e.async=!0;e.src=("https:"===document.location.protocol?"https://":"http://")+"cdn.segment.com/analytics.js/v1/"+t+"/analytics.min.js";var n=document.getElementsByTagName("script")[0];n.parentNode.insertBefore(e,n)};analytics.SNIPPET_VERSION="3.1.0";
analytics.load("8UDQfnf3cyFSTsM4YANnW5sXmgZVILbA");
analytics.page();
}}();
analytics.ready(function () {
ga('require', 'linker');
ga('linker:autoLink', ['scrapinghub.com', 'crawlera.com']);
ga('linker:autoLink', ['zyte.com']);
});
</script>
{% endblock %}

35
docs/conf.py
View File

@ -1,5 +1,3 @@
# -*- coding: utf-8 -*-
#
# Scrapy documentation build configuration file, created by
# sphinx-quickstart on Mon Nov 24 12:02:52 2008.
#
@ -51,7 +49,7 @@ master_doc = 'index'
# General information about the project.
project = 'Scrapy'
copyright = '2008–{}, Scrapy developers'.format(datetime.now().year)
copyright = f'2008–{datetime.now().year}, Scrapy developers'
# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
@ -102,6 +100,9 @@ exclude_trees = ['.build']
# The name of the Pygments (syntax highlighting) style to use.
pygments_style = 'sphinx'
# List of Sphinx warnings that will not be raised
suppress_warnings = ['epub.unknown_project_files']
# Options for HTML output
# -----------------------
@ -121,7 +122,6 @@ html_theme = 'sphinx_rtd_theme'
import sphinx_rtd_theme
html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
# The style sheet to use for HTML and HTML Help pages. A file of that name
# must exist either in Sphinx' static/ path, or in one of the custom paths
# given in html_static_path.
@ -182,6 +182,10 @@ html_copy_source = True
# Output file base name for HTML help builder.
htmlhelp_basename = 'Scrapydoc'
html_css_files = [
'custom.css',
]
# Options for LaTeX output
# ------------------------
@ -280,8 +284,11 @@ coverage_ignore_pyobjects = [
# -------------------------------------
intersphinx_mapping = {
'attrs': ('https://www.attrs.org/en/stable/', None),
'coverage': ('https://coverage.readthedocs.io/en/stable', None),
'cryptography' : ('https://cryptography.io/en/latest/', None),
'cssselect': ('https://cssselect.readthedocs.io/en/latest', None),
'itemloaders': ('https://itemloaders.readthedocs.io/en/latest/', None),
'pytest': ('https://docs.pytest.org/en/latest', None),
'python': ('https://docs.python.org/3', None),
'sphinx': ('https://www.sphinx-doc.org/en/master', None),
@ -295,3 +302,23 @@ intersphinx_mapping = {
# ------------------------------------
hoverxref_auto_ref = True
hoverxref_role_types = {
"class": "tooltip",
"confval": "tooltip",
"hoverxref": "tooltip",
"mod": "tooltip",
"ref": "tooltip",
}
hoverxref_roles = ['command', 'reqmeta', 'setting', 'signal']
def setup(app):
app.connect('autodoc-skip-member', maybe_skip_member)
def maybe_skip_member(app, what, name, obj, skip, options):
if not skip:
# autodocs was generating a text "alias of" for the following members
# https://github.com/sphinx-doc/sphinx/issues/4422
return name in {'default_item_class', 'default_selector_class'}
return skip

23
docs/contributing.rst
View File

@ -108,6 +108,11 @@ Well-written patches should:
tox -e docs-coverage
* if you are removing deprecated code, first make sure that at least 1 year
(12 months) has passed since the release that introduced the deprecation.
See :ref:`deprecation-policy`.
.. _submitting-patches:
Submitting patches
@ -135,7 +140,7 @@ original pull request author hasn't had time to address them.
In this case consider picking up this pull request: open
a new pull request with all commits from the original pull request, as well as
additional changes to address the raised issues. Doing so helps a lot; it is
not considered rude as soon as the original author is acknowledged by keeping
not considered rude as long as the original author is acknowledged by keeping
his/her commits.
You can pull an existing pull request to a local branch
@ -155,6 +160,9 @@ Finally, try to keep aesthetic changes (:pep:`8` compliance, unused imports
removal, etc) in separate commits from functional changes. This will make pull
requests easier to review and more likely to get merged.
.. _coding-style:
Coding style
============
@ -163,7 +171,7 @@ Scrapy:
* Unless otherwise specified, follow :pep:`8`.
* It's OK to use lines longer than 80 chars if it improves the code
* It's OK to use lines longer than 79 chars if it improves the code
readability.
* Don't put your name in the code you contribute; git provides enough
@ -191,6 +199,17 @@ In any case, if something is covered in a docstring, use the
documentation instead of duplicating the docstring in files within the
``docs/`` directory.
Documentation updates that cover new or modified features must use Sphinx’s
:rst:dir:`versionadded` and :rst:dir:`versionchanged` directives. Use
``VERSION`` as version, we will replace it with the actual version right before
the corresponding release. When we release a new major or minor version of
Scrapy, we remove these directives if they are older than 3 years.
Documentation about deprecated features must be removed as those features are
deprecated, so that new readers do not run into it. New deprecations and
deprecation removals are documented in the :ref:`release notes <news>`.
Tests
=====

77
docs/faq.rst
View File

@ -64,20 +64,6 @@ Here's an example spider using BeautifulSoup API, with ``lxml`` as the HTML pars
.. _BeautifulSoup's official documentation: https://www.crummy.com/software/BeautifulSoup/bs4/doc/#specifying-the-parser-to-use
.. _faq-python-versions:
What Python versions does Scrapy support?
-----------------------------------------
Scrapy is supported under Python 3.5+
under CPython (default Python implementation) and PyPy (starting with PyPy 5.9).
Python 3 support was added in Scrapy 1.1.
PyPy support was added in Scrapy 1.4, PyPy3 support was added in Scrapy 1.5.
Python 2 support was dropped in Scrapy 2.0.
.. note::
For Python 3 support on Windows, it is recommended to use
Anaconda/Miniconda as :ref:`outlined in the installation guide <intro-install-windows>`.
Did Scrapy "steal" X from Django?
---------------------------------
@ -159,6 +145,41 @@ How can I make Scrapy consume less memory?
See previous question.
How can I prevent memory errors due to many allowed domains?
------------------------------------------------------------
If you have a spider with a long list of
:attr:`~scrapy.spiders.Spider.allowed_domains` (e.g. 50,000+), consider
replacing the default
:class:`~scrapy.spidermiddlewares.offsite.OffsiteMiddleware` spider middleware
with a :ref:`custom spider middleware <custom-spider-middleware>` that requires
less memory. For example:
- If your domain names are similar enough, use your own regular expression
instead joining the strings in
:attr:`~scrapy.spiders.Spider.allowed_domains` into a complex regular
expression.
- If you can `meet the installation requirements`_, use pyre2_ instead of
Python’s re_ to compile your URL-filtering regular expression. See
:issue:`1908`.
See also other suggestions at `StackOverflow`_.
.. note:: Remember to disable
:class:`scrapy.spidermiddlewares.offsite.OffsiteMiddleware` when you enable
your custom implementation::
SPIDER_MIDDLEWARES = {
'scrapy.spidermiddlewares.offsite.OffsiteMiddleware': None,
'myproject.middlewares.CustomOffsiteMiddleware': 500,
}
.. _meet the installation requirements: https://github.com/andreasvc/pyre2#installation
.. _pyre2: https://github.com/andreasvc/pyre2
.. _re: https://docs.python.org/library/re.html
.. _StackOverflow: https://stackoverflow.com/q/36440681/939364
Can I use Basic HTTP Authentication in my spiders?
--------------------------------------------------
@ -250,15 +271,15 @@ Simplest way to dump all my scraped items into a JSON/CSV/XML file?
To dump into a JSON file::
scrapy crawl myspider -o items.json
scrapy crawl myspider -O items.json
To dump into a CSV file::
scrapy crawl myspider -o items.csv
scrapy crawl myspider -O items.csv
To dump into a XML file::
scrapy crawl myspider -o items.xml
scrapy crawl myspider -O items.xml
For more information see :ref:`topics-feed-exports`
@ -342,15 +363,15 @@ method for this purpose. For example::
from copy import deepcopy
from scrapy.item import BaseItem
from itemadapter import is_item, ItemAdapter
class MultiplyItemsMiddleware:
def process_spider_output(self, response, result, spider):
for item in result:
if isinstance(item, (BaseItem, dict)):
for _ in range(item['multiply_by']):
if is_item(item):
adapter = ItemAdapter(item)
for _ in range(adapter['multiply_by']):
yield deepcopy(item)
Does Scrapy support IPv6 addresses?
@ -371,6 +392,20 @@ Twisted reactor is :class:`twisted.internet.selectreactor.SelectReactor`. Switch
different reactor is possible by using the :setting:`TWISTED_REACTOR` setting.
.. _faq-stop-response-download:
How can I cancel the download of a given response?
--------------------------------------------------
In some situations, it might be useful to stop the download of a certain response.
For instance, sometimes you can determine whether or not you need the full contents
of a response by inspecting its headers or the first bytes of its body. In that case,
you could save resources by attaching a handler to the :class:`~scrapy.signals.bytes_received`
or :class:`~scrapy.signals.headers_received` signals and raising a
:exc:`~scrapy.exceptions.StopDownload` exception. Please refer to the
:ref:`topics-stop-response-download` topic for additional information and examples.
.. _has been reported: https://github.com/scrapy/scrapy/issues/2905
.. _user agents: https://en.wikipedia.org/wiki/User_agent
.. _LIFO: https://en.wikipedia.org/wiki/Stack_(abstract_data_type)

5
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@ -78,7 +78,6 @@ Basic concepts
topics/settings
topics/exceptions
:doc:`topics/commands`
Learn about the command-line tool used to manage your Scrapy project.
@ -228,6 +227,7 @@ Extending Scrapy
topics/extensions
topics/api
topics/signals
topics/scheduler
topics/exporters
@ -249,6 +249,9 @@ Extending Scrapy
:doc:`topics/signals`
See all available signals and how to work with them.
:doc:`topics/scheduler`
Understand the scheduler component.
:doc:`topics/exporters`
Quickly export your scraped items to a file (XML, CSV, etc).

51
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@ -4,12 +4,19 @@
Installation guide
==================
.. _faq-python-versions:
Supported Python versions
=========================
Scrapy requires Python 3.6+, either the CPython implementation (default) or
the PyPy 7.2.0+ implementation (see :ref:`python:implementations`).
.. _intro-install-scrapy:
Installing Scrapy
=================
Scrapy runs on Python 3.5 or above under CPython (default Python
implementation) and PyPy (starting with PyPy 5.9).
If you're using `Anaconda`_ or `Miniconda`_, you can install the package from
the `conda-forge`_ channel, which has up-to-date packages for Linux, Windows
and macOS.
@ -23,13 +30,13 @@ you can install Scrapy and its dependencies from PyPI with::
pip install Scrapy
We strongly recommend that you install Scrapy in :ref:`a dedicated virtualenv <intro-using-virtualenv>`,
to avoid conflicting with your system packages.
Note that sometimes this may require solving compilation issues for some Scrapy
dependencies depending on your operating system, so be sure to check the
:ref:`intro-install-platform-notes`.
We strongly recommend that you install Scrapy in :ref:`a dedicated virtualenv <intro-using-virtualenv>`,
to avoid conflicting with your system packages.
For more detailed and platform specifics instructions, as well as
troubleshooting information, read on.
@ -63,10 +70,9 @@ In case of any trouble related to these dependencies,
please refer to their respective installation instructions:
* `lxml installation`_
* `cryptography installation`_
* :doc:`cryptography installation <cryptography:installation>`
.. _lxml installation: https://lxml.de/installation.html
.. _cryptography installation: https://cryptography.io/en/latest/installation/
.. _intro-using-virtualenv:
@ -112,6 +118,27 @@ Once you've installed `Anaconda`_ or `Miniconda`_, install Scrapy with::
conda install -c conda-forge scrapy
To install Scrapy on Windows using ``pip``:
.. warning::
This installation method requires “Microsoft Visual C++” for installing some
Scrapy dependencies, which demands significantly more disk space than Anaconda.
#. Download and execute `Microsoft C++ Build Tools`_ to install the Visual Studio Installer.
#. Run the Visual Studio Installer.
#. Under the Workloads section, select **C++ build tools**.
#. Check the installation details and make sure following packages are selected as optional components:
* **MSVC** (e.g MSVC v142 - VS 2019 C++ x64/x86 build tools (v14.23) )
* **Windows SDK** (e.g Windows 10 SDK (10.0.18362.0))
#. Install the Visual Studio Build Tools.
Now, you should be able to :ref:`install Scrapy <intro-install-scrapy>` using ``pip``.
.. _intro-install-ubuntu:
@ -205,8 +232,8 @@ PyPy
We recommend using the latest PyPy version. The version tested is 5.9.0.
For PyPy3, only Linux installation was tested.
Most Scrapy dependencides now have binary wheels for CPython, but not for PyPy.
This means that these dependecies will be built during installation.
Most Scrapy dependencies now have binary wheels for CPython, but not for PyPy.
This means that these dependencies will be built during installation.
On macOS, you are likely to face an issue with building Cryptography dependency,
solution to this problem is described
`here <https://github.com/pyca/cryptography/issues/2692#issuecomment-272773481>`_,
@ -259,10 +286,10 @@ For details, see `Issue #2473 <https://github.com/scrapy/scrapy/issues/2473>`_.
.. _cryptography: https://cryptography.io/en/latest/
.. _pyOpenSSL: https://pypi.org/project/pyOpenSSL/
.. _setuptools: https://pypi.python.org/pypi/setuptools
.. _AUR Scrapy package: https://aur.archlinux.org/packages/scrapy/
.. _homebrew: https://brew.sh/
.. _zsh: https://www.zsh.org/
.. _Scrapinghub: https://scrapinghub.com
.. _Anaconda: https://docs.anaconda.com/anaconda/
.. _Miniconda: https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html
.. _Visual Studio: https://docs.microsoft.com/en-us/visualstudio/install/install-visual-studio
.. _Microsoft C++ Build Tools: https://visualstudio.microsoft.com/visual-cpp-build-tools/
.. _conda-forge: https://conda-forge.org/

26
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@ -42,30 +42,18 @@ http://quotes.toscrape.com, following the pagination::
if next_page is not None:
yield response.follow(next_page, self.parse)
Put this in a text file, name it to something like ``quotes_spider.py``
and run the spider using the :command:`runspider` command::
scrapy runspider quotes_spider.py -o quotes.json
scrapy runspider quotes_spider.py -o quotes.jl
When this finishes you will have in the ``quotes.jl`` file a list of the
quotes in JSON Lines format, containing text and author, looking like this::
When this finishes you will have in the ``quotes.json`` file a list of the
quotes in JSON format, containing text and author, looking like this (reformatted
here for better readability)::
[{
"author": "Jane Austen",
"text": "\u201cThe person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.\u201d"
},
{
"author": "Groucho Marx",
"text": "\u201cOutside of a dog, a book is man's best friend. Inside of a dog it's too dark to read.\u201d"
},
{
"author": "Steve Martin",
"text": "\u201cA day without sunshine is like, you know, night.\u201d"
},
...]
{"author": "Jane Austen", "text": "\u201cThe person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.\u201d"}
{"author": "Steve Martin", "text": "\u201cA day without sunshine is like, you know, night.\u201d"}
{"author": "Garrison Keillor", "text": "\u201cAnyone who thinks sitting in church can make you a Christian must also think that sitting in a garage can make you a car.\u201d"}
...
What just happened?

38
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@ -25,16 +25,16 @@ Scrapy.
If you're already familiar with other languages, and want to learn Python quickly, the `Python Tutorial`_ is a good resource.
If you're new to programming and want to start with Python, the following books
may be useful to you:
may be useful to you:
* `Automate the Boring Stuff With Python`_
* `How To Think Like a Computer Scientist`_
* `How To Think Like a Computer Scientist`_
* `Learn Python 3 The Hard Way`_
* `Learn Python 3 The Hard Way`_
You can also take a look at `this list of Python resources for non-programmers`_,
as well as the `suggested resources in the learnpython-subreddit`_.
as well as the `suggested resources in the learnpython-subreddit`_.
.. _Python: https://www.python.org/
.. _this list of Python resources for non-programmers: https://wiki.python.org/moin/BeginnersGuide/NonProgrammers
@ -62,7 +62,7 @@ This will create a ``tutorial`` directory with the following contents::
__init__.py
items.py # project items definition file
middlewares.py # project middlewares file
pipelines.py # project pipelines file
@ -101,10 +101,10 @@ This is the code for our first Spider. Save it in a file named
def parse(self, response):
page = response.url.split("/")[-2]
filename = 'quotes-%s.html' % page
filename = f'quotes-{page}.html'
with open(filename, 'wb') as f:
f.write(response.body)
self.log('Saved file %s' % filename)
self.log(f'Saved file {filename}')
As you can see, our Spider subclasses :class:`scrapy.Spider <scrapy.spiders.Spider>`
@ -190,7 +190,7 @@ for your spider::
def parse(self, response):
page = response.url.split("/")[-2]
filename = 'quotes-%s.html' % page
filename = f'quotes-{page}.html'
with open(filename, 'wb') as f:
f.write(response.body)
@ -287,8 +287,8 @@ to be scraped, you can at least get **some** data.
Besides the :meth:`~scrapy.selector.SelectorList.getall` and
:meth:`~scrapy.selector.SelectorList.get` methods, you can also use
the :meth:`~scrapy.selector.SelectorList.re` method to extract using `regular
expressions`_:
the :meth:`~scrapy.selector.SelectorList.re` method to extract using
:doc:`regular expressions <library/re>`:
>>> response.css('title::text').re(r'Quotes.*')
['Quotes to Scrape']
@ -305,7 +305,6 @@ with a selector (see :ref:`topics-developer-tools`).
`Selector Gadget`_ is also a nice tool to quickly find CSS selector for
visually selected elements, which works in many browsers.
.. _regular expressions: https://docs.python.org/3/library/re.html
.. _Selector Gadget: https://selectorgadget.com/
@ -406,8 +405,6 @@ to get all of them:
from sys import version_info
.. skip: next if(version_info < (3, 6), reason="Only Python 3.6+ dictionaries match the output")
Having figured out how to extract each bit, we can now iterate over all the
quotes elements and put them together into a Python dictionary:
@ -465,16 +462,15 @@ Storing the scraped data
The simplest way to store the scraped data is by using :ref:`Feed exports
<topics-feed-exports>`, with the following command::
scrapy crawl quotes -o quotes.json
scrapy crawl quotes -O quotes.json
That will generate an ``quotes.json`` file containing all scraped items,
That will generate a ``quotes.json`` file containing all scraped items,
serialized in `JSON`_.
For historic reasons, Scrapy appends to a given file instead of overwriting
its contents. If you run this command twice without removing the file
before the second time, you'll end up with a broken JSON file.
You can also use other formats, like `JSON Lines`_::
The ``-O`` command-line switch overwrites any existing file; use ``-o`` instead
to append new content to any existing file. However, appending to a JSON file
makes the file contents invalid JSON. When appending to a file, consider
using a different serialization format, such as `JSON Lines`_::
scrapy crawl quotes -o quotes.jl
@ -705,7 +701,7 @@ Using spider arguments
You can provide command line arguments to your spiders by using the ``-a``
option when running them::
scrapy crawl quotes -o quotes-humor.json -a tag=humor
scrapy crawl quotes -O quotes-humor.json -a tag=humor
These arguments are passed to the Spider's ``__init__`` method and become
spider attributes by default.

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8
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@ -1,4 +1,4 @@
Sphinx>=2.1
sphinx-hoverxref
sphinx-notfound-page
sphinx_rtd_theme
Sphinx>=3.0
sphinx-hoverxref>=0.2b1
sphinx-notfound-page>=0.4
sphinx-rtd-theme>=0.5.2

4
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@ -4,8 +4,6 @@
Core API
========
.. versionadded:: 0.15
This section documents the Scrapy core API, and it's intended for developers of
extensions and middlewares.
@ -91,7 +89,7 @@ how you :ref:`configure the downloader middlewares
provided while constructing the crawler, and it is created after the
arguments given in the :meth:`crawl` method.
.. method:: crawl(\*args, \**kwargs)
.. method:: crawl(*args, **kwargs)
Starts the crawler by instantiating its spider class with the given
``args`` and ``kwargs`` arguments, while setting the execution engine in

7
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@ -87,8 +87,9 @@ of the system, and triggering events when certain actions occur. See the
Scheduler
---------
The Scheduler receives requests from the engine and enqueues them for feeding
them later (also to the engine) when the engine requests them.
The :ref:`scheduler <topics-scheduler>` receives requests from the engine and
enqueues them for feeding them later (also to the engine) when the engine
requests them.
.. _component-downloader:
@ -104,7 +105,7 @@ Spiders
-------
Spiders are custom classes written by Scrapy users to parse responses and
extract items (aka scraped items) from them or additional requests to
extract :ref:`items <topics-items>` from them or additional requests to
follow. For more information see :ref:`topics-spiders`.
.. _component-pipelines:

25
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@ -1,16 +1,19 @@
.. _using-asyncio:
=======
asyncio
=======
.. versionadded:: 2.0
Scrapy has partial support :mod:`asyncio`. After you :ref:`install the asyncio
reactor <install-asyncio>`, you may use :mod:`asyncio` and
Scrapy has partial support for :mod:`asyncio`. After you :ref:`install the
asyncio reactor <install-asyncio>`, you may use :mod:`asyncio` and
:mod:`asyncio`-powered libraries in any :doc:`coroutine <coroutines>`.
.. warning:: :mod:`asyncio` support in Scrapy is experimental. Future Scrapy
versions may introduce related changes without a deprecation
period or warning.
.. warning:: :mod:`asyncio` support in Scrapy is experimental, and not yet
recommended for production environments. Future Scrapy versions
may introduce related changes without a deprecation period or
warning.
.. _install-asyncio:
@ -26,3 +29,15 @@ reactor manually. You can do that using
:func:`~scrapy.utils.reactor.install_reactor`::
install_reactor('twisted.internet.asyncioreactor.AsyncioSelectorReactor')
.. _using-custom-loops:
Using custom asyncio loops
==========================
You can also use custom asyncio event loops with the asyncio reactor. Set the
:setting:`ASYNCIO_EVENT_LOOP` setting to the import path of the desired event loop class to
use it instead of the default asyncio event loop.

2
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@ -128,8 +128,6 @@ The maximum download delay (in seconds) to be set in case of high latencies.
AUTOTHROTTLE_TARGET_CONCURRENCY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. versionadded:: 1.1
Default: ``1.0``
Average number of requests Scrapy should be sending in parallel to remote

7
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@ -4,8 +4,6 @@
Benchmarking
============
.. versionadded:: 0.17
Scrapy comes with a simple benchmarking suite that spawns a local HTTP server
and crawls it at the maximum possible speed. The goal of this benchmarking is
to get an idea of how Scrapy performs in your hardware, in order to have a
@ -83,5 +81,6 @@ follow links, any custom spider you write will probably do more stuff which
results in slower crawl rates. How slower depends on how much your spider does
and how well it's written.
In the future, more cases will be added to the benchmarking suite to cover
other common scenarios.
Use scrapy-bench_ for more complex benchmarking.
.. _scrapy-bench: https://github.com/scrapy/scrapy-bench

12
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@ -6,8 +6,6 @@
Command line tool
=================
.. versionadded:: 0.10
Scrapy is controlled through the ``scrapy`` command-line tool, to be referred
here as the "Scrapy tool" to differentiate it from the sub-commands, which we
just call "commands" or "Scrapy commands".
@ -468,7 +466,7 @@ Supported options:
* ``--callback`` or ``-c``: spider method to use as callback for parsing the
response
* ``--meta`` or ``-m``: additional request meta that will be passed to the callback
* ``--meta`` or ``-m``: additional request meta that will be passed to the callback
request. This must be a valid json string. Example: --meta='{"foo" : "bar"}'
* ``--cbkwargs``: additional keyword arguments that will be passed to the callback.
@ -491,6 +489,10 @@ Supported options:
* ``--verbose`` or ``-v``: display information for each depth level
* ``--output`` or ``-o``: dump scraped items to a file
.. versionadded:: 2.3
.. skip: start
Usage example::
@ -562,8 +564,6 @@ and Platform info, which is useful for bug reports.
bench
-----
.. versionadded:: 0.17
* Syntax: ``scrapy bench``
* Requires project: *no*
@ -598,8 +598,6 @@ Example:
Register commands via setup.py entry points
-------------------------------------------
.. note:: This is an experimental feature, use with caution.
You can also add Scrapy commands from an external library by adding a
``scrapy.commands`` section in the entry points of the library ``setup.py``
file.

10
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@ -4,8 +4,6 @@
Spiders Contracts
=================
.. versionadded:: 0.15
Testing spiders can get particularly annoying and while nothing prevents you
from writing unit tests the task gets cumbersome quickly. Scrapy offers an
integrated way of testing your spiders by the means of contracts.
@ -78,10 +76,10 @@ override three methods:
.. module:: scrapy.contracts
.. class:: Contract(method, \*args)
.. class:: Contract(method, *args)
:param method: callback function to which the contract is associated
:type method: function
:type method: collections.abc.Callable
:param args: list of arguments passed into the docstring (whitespace
separated)
@ -136,7 +134,7 @@ Detecting check runs
====================
When ``scrapy check`` is running, the ``SCRAPY_CHECK`` environment variable is
set to the ``true`` string. You can use `os.environ`_ to perform any change to
set to the ``true`` string. You can use :data:`os.environ` to perform any change to
your spiders or your settings when ``scrapy check`` is used::
import os
@ -148,5 +146,3 @@ your spiders or your settings when ``scrapy check`` is used::
def __init__(self):
if os.environ.get('SCRAPY_CHECK'):
pass # Do some scraper adjustments when a check is running
.. _os.environ: https://docs.python.org/3/library/os.html#os.environ

37
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@ -7,10 +7,6 @@ Coroutines
Scrapy has :ref:`partial support <coroutine-support>` for the
:ref:`coroutine syntax <async>`.
.. warning:: :mod:`asyncio` support in Scrapy is experimental. Future Scrapy
versions may introduce related API and behavior changes without a
deprecation period or warning.
.. _coroutine-support:
Supported callables
@ -21,19 +17,14 @@ hence use coroutine syntax (e.g. ``await``, ``async for``, ``async with``):
- :class:`~scrapy.http.Request` callbacks.
The following are known caveats of the current implementation that we aim
to address in future versions of Scrapy:
- The callback output is not processed until the whole callback finishes.
.. note:: The callback output is not processed until the whole callback
finishes.
As a side effect, if the callback raises an exception, none of its
output is processed.
- Because `asynchronous generators were introduced in Python 3.6`_, you
can only use ``yield`` if you are using Python 3.6 or later.
If you need to output multiple items or requests and you are using
Python 3.5, return an iterable (e.g. a list) instead.
This is a known caveat of the current implementation that we aim to
address in a future version of Scrapy.
- The :meth:`process_item` method of
:ref:`item pipelines <topics-item-pipeline>`.
@ -48,8 +39,6 @@ hence use coroutine syntax (e.g. ``await``, ``async for``, ``async with``):
- :ref:`Signal handlers that support deferreds <signal-deferred>`.
.. _asynchronous generators were introduced in Python 3.6: https://www.python.org/dev/peps/pep-0525/
Usage
=====
@ -57,27 +46,34 @@ There are several use cases for coroutines in Scrapy. Code that would
return Deferreds when written for previous Scrapy versions, such as downloader
middlewares and signal handlers, can be rewritten to be shorter and cleaner::
from itemadapter import ItemAdapter
class DbPipeline:
def _update_item(self, data, item):
item['field'] = data
adapter = ItemAdapter(item)
adapter['field'] = data
return item
def process_item(self, item, spider):
dfd = db.get_some_data(item['id'])
adapter = ItemAdapter(item)
dfd = db.get_some_data(adapter['id'])
dfd.addCallback(self._update_item, item)
return dfd
becomes::
from itemadapter import ItemAdapter
class DbPipeline:
async def process_item(self, item, spider):
item['field'] = await db.get_some_data(item['id'])
adapter = ItemAdapter(item)
adapter['field'] = await db.get_some_data(adapter['id'])
return item
Coroutines may be used to call asynchronous code. This includes other
coroutines, functions that return Deferreds and functions that return
`awaitable objects`_ such as :class:`~asyncio.Future`. This means you can use
many useful Python libraries providing such code::
:term:`awaitable objects <awaitable>` such as :class:`~asyncio.Future`.
This means you can use many useful Python libraries providing such code::
class MySpider(Spider):
# ...
@ -107,4 +103,3 @@ Common use cases for asynchronous code include:
:ref:`the screenshot pipeline example<ScreenshotPipeline>`).
.. _aio-libs: https://github.com/aio-libs
.. _awaitable objects: https://docs.python.org/3/glossary.html#term-awaitable

32
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@ -14,7 +14,7 @@ spiders come in.
Popular choices for deploying Scrapy spiders are:
* :ref:`Scrapyd <deploy-scrapyd>` (open source)
* :ref:`Scrapy Cloud <deploy-scrapy-cloud>` (cloud-based)
* :ref:`Zyte Scrapy Cloud <deploy-scrapy-cloud>` (cloud-based)
.. _deploy-scrapyd:
@ -32,28 +32,28 @@ Scrapyd is maintained by some of the Scrapy developers.
.. _deploy-scrapy-cloud:
Deploying to Scrapy Cloud
=========================
Deploying to Zyte Scrapy Cloud
==============================
`Scrapy Cloud`_ is a hosted, cloud-based service by `Scrapinghub`_,
the company behind Scrapy.
`Zyte Scrapy Cloud`_ is a hosted, cloud-based service by Zyte_, the company
behind Scrapy.
Scrapy Cloud removes the need to setup and monitor servers
and provides a nice UI to manage spiders and review scraped items,
logs and stats.
Zyte Scrapy Cloud removes the need to setup and monitor servers and provides a
nice UI to manage spiders and review scraped items, logs and stats.
To deploy spiders to Scrapy Cloud you can use the `shub`_ command line tool.
Please refer to the `Scrapy Cloud documentation`_ for more information.
To deploy spiders to Zyte Scrapy Cloud you can use the `shub`_ command line
tool.
Please refer to the `Zyte Scrapy Cloud documentation`_ for more information.
Scrapy Cloud is compatible with Scrapyd and one can switch between
Zyte Scrapy Cloud is compatible with Scrapyd and one can switch between
them as needed - the configuration is read from the ``scrapy.cfg`` file
just like ``scrapyd-deploy``.
.. _Scrapyd: https://github.com/scrapy/scrapyd
.. _Deploying your project: https://scrapyd.readthedocs.io/en/latest/deploy.html
.. _Scrapy Cloud: https://scrapinghub.com/scrapy-cloud
.. _Scrapyd: https://github.com/scrapy/scrapyd
.. _scrapyd-client: https://github.com/scrapy/scrapyd-client
.. _shub: https://doc.scrapinghub.com/shub.html
.. _scrapyd-deploy documentation: https://scrapyd.readthedocs.io/en/latest/deploy.html
.. _Scrapy Cloud documentation: https://doc.scrapinghub.com/scrapy-cloud.html
.. _Scrapinghub: https://scrapinghub.com/
.. _shub: https://shub.readthedocs.io/en/latest/
.. _Zyte: https://zyte.com/
.. _Zyte Scrapy Cloud: https://www.zyte.com/scrapy-cloud/
.. _Zyte Scrapy Cloud documentation: https://docs.zyte.com/scrapy-cloud.html

147
docs/topics/developer-tools.rst
View File

@ -5,9 +5,9 @@ Using your browser's Developer Tools for scraping
=================================================
Here is a general guide on how to use your browser's Developer Tools
to ease the scraping process. Today almost all browsers come with
to ease the scraping process. Today almost all browsers come with
built in `Developer Tools`_ and although we will use Firefox in this
guide, the concepts are applicable to any other browser.
guide, the concepts are applicable to any other browser.
In this guide we'll introduce the basic tools to use from a browser's
Developer Tools by scraping `quotes.toscrape.com`_.
@ -41,16 +41,16 @@ Therefore, you should keep in mind the following things:
Inspecting a website
====================
By far the most handy feature of the Developer Tools is the `Inspector`
feature, which allows you to inspect the underlying HTML code of
any webpage. To demonstrate the Inspector, let's look at the
By far the most handy feature of the Developer Tools is the `Inspector`
feature, which allows you to inspect the underlying HTML code of
any webpage. To demonstrate the Inspector, let's look at the
`quotes.toscrape.com`_-site.
On the site we have a total of ten quotes from various authors with specific
tags, as well as the Top Ten Tags. Let's say we want to extract all the quotes
on this page, without any meta-information about authors, tags, etc.
tags, as well as the Top Ten Tags. Let's say we want to extract all the quotes
on this page, without any meta-information about authors, tags, etc.
Instead of viewing the whole source code for the page, we can simply right click
Instead of viewing the whole source code for the page, we can simply right click
on a quote and select ``Inspect Element (Q)``, which opens up the `Inspector`.
In it you should see something like this:
@ -97,16 +97,16 @@ Then, back to your web browser, right-click on the ``span`` tag, select
>>> response.xpath('/html/body/div/div[2]/div[1]/div[1]/span[1]/text()').getall()
['“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”']
Adding ``text()`` at the end we are able to extract the first quote with this
Adding ``text()`` at the end we are able to extract the first quote with this
basic selector. But this XPath is not really that clever. All it does is
go down a desired path in the source code starting from ``html``. So let's
see if we can refine our XPath a bit:
go down a desired path in the source code starting from ``html``. So let's
see if we can refine our XPath a bit:
If we check the `Inspector` again we'll see that directly beneath our
expanded ``div`` tag we have nine identical ``div`` tags, each with the
same attributes as our first. If we expand any of them, we'll see the same
If we check the `Inspector` again we'll see that directly beneath our
expanded ``div`` tag we have nine identical ``div`` tags, each with the
same attributes as our first. If we expand any of them, we'll see the same
structure as with our first quote: Two ``span`` tags and one ``div`` tag. We can
expand each ``span`` tag with the ``class="text"`` inside our ``div`` tags and
expand each ``span`` tag with the ``class="text"`` inside our ``div`` tags and
see each quote:
.. code-block:: html
@ -121,7 +121,7 @@ see each quote:
With this knowledge we can refine our XPath: Instead of a path to follow,
we'll simply select all ``span`` tags with the ``class="text"`` by using
we'll simply select all ``span`` tags with the ``class="text"`` by using
the `has-class-extension`_:
>>> response.xpath('//span[has-class("text")]/text()').getall()
@ -130,45 +130,45 @@ the `has-class-extension`_:
'“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.”',
...]
And with one simple, cleverer XPath we are able to extract all quotes from
the page. We could have constructed a loop over our first XPath to increase
the number of the last ``div``, but this would have been unnecessarily
And with one simple, cleverer XPath we are able to extract all quotes from
the page. We could have constructed a loop over our first XPath to increase
the number of the last ``div``, but this would have been unnecessarily
complex and by simply constructing an XPath with ``has-class("text")``
we were able to extract all quotes in one line.
we were able to extract all quotes in one line.
The `Inspector` has a lot of other helpful features, such as searching in the
The `Inspector` has a lot of other helpful features, such as searching in the
source code or directly scrolling to an element you selected. Let's demonstrate
a use case:
a use case:
Say you want to find the ``Next`` button on the page. Type ``Next`` into the
search bar on the top right of the `Inspector`. You should get two results.
The first is a ``li`` tag with the ``class="next"``, the second the text
Say you want to find the ``Next`` button on the page. Type ``Next`` into the
search bar on the top right of the `Inspector`. You should get two results.
The first is a ``li`` tag with the ``class="next"``, the second the text
of an ``a`` tag. Right click on the ``a`` tag and select ``Scroll into View``.
If you hover over the tag, you'll see the button highlighted. From here
we could easily create a :ref:`Link Extractor <topics-link-extractors>` to
follow the pagination. On a simple site such as this, there may not be
we could easily create a :ref:`Link Extractor <topics-link-extractors>` to
follow the pagination. On a simple site such as this, there may not be
the need to find an element visually but the ``Scroll into View`` function
can be quite useful on complex sites.
can be quite useful on complex sites.
Note that the search bar can also be used to search for and test CSS
selectors. For example, you could search for ``span.text`` to find
all quote texts. Instead of a full text search, this searches for
exactly the ``span`` tag with the ``class="text"`` in the page.
selectors. For example, you could search for ``span.text`` to find
all quote texts. Instead of a full text search, this searches for
exactly the ``span`` tag with the ``class="text"`` in the page.
.. _topics-network-tool:
The Network-tool
================
While scraping you may come across dynamic webpages where some parts
of the page are loaded dynamically through multiple requests. While
this can be quite tricky, the `Network`-tool in the Developer Tools
of the page are loaded dynamically through multiple requests. While
this can be quite tricky, the `Network`-tool in the Developer Tools
greatly facilitates this task. To demonstrate the Network-tool, let's
take a look at the page `quotes.toscrape.com/scroll`_.
take a look at the page `quotes.toscrape.com/scroll`_.
The page is quite similar to the basic `quotes.toscrape.com`_-page,
but instead of the above-mentioned ``Next`` button, the page
automatically loads new quotes when you scroll to the bottom. We
could go ahead and try out different XPaths directly, but instead
The page is quite similar to the basic `quotes.toscrape.com`_-page,
but instead of the above-mentioned ``Next`` button, the page
automatically loads new quotes when you scroll to the bottom. We
could go ahead and try out different XPaths directly, but instead
we'll check another quite useful command from the Scrapy shell:
.. skip: next
@ -179,9 +179,9 @@ we'll check another quite useful command from the Scrapy shell:
(...)
>>> view(response)
A browser window should open with the webpage but with one
crucial difference: Instead of the quotes we just see a greenish
bar with the word ``Loading...``.
A browser window should open with the webpage but with one
crucial difference: Instead of the quotes we just see a greenish
bar with the word ``Loading...``.
.. image:: _images/network_01.png
:width: 777
@ -189,21 +189,21 @@ bar with the word ``Loading...``.
:alt: Response from quotes.toscrape.com/scroll
The ``view(response)`` command let's us view the response our
shell or later our spider receives from the server. Here we see
that some basic template is loaded which includes the title,
shell or later our spider receives from the server. Here we see
that some basic template is loaded which includes the title,
the login-button and the footer, but the quotes are missing. This
tells us that the quotes are being loaded from a different request
than ``quotes.toscrape/scroll``.
than ``quotes.toscrape/scroll``.
If you click on the ``Network`` tab, you will probably only see
two entries. The first thing we do is enable persistent logs by
clicking on ``Persist Logs``. If this option is disabled, the
If you click on the ``Network`` tab, you will probably only see
two entries. The first thing we do is enable persistent logs by
clicking on ``Persist Logs``. If this option is disabled, the
log is automatically cleared each time you navigate to a different
page. Enabling this option is a good default, since it gives us
control on when to clear the logs.
page. Enabling this option is a good default, since it gives us
control on when to clear the logs.
If we reload the page now, you'll see the log get populated with six
new requests.
new requests.
.. image:: _images/network_02.png
:width: 777
@ -212,31 +212,31 @@ new requests.
Here we see every request that has been made when reloading the page
and can inspect each request and its response. So let's find out
where our quotes are coming from:
where our quotes are coming from:
First click on the request with the name ``scroll``. On the right
First click on the request with the name ``scroll``. On the right
you can now inspect the request. In ``Headers`` you'll find details
about the request headers, such as the URL, the method, the IP-address,
and so on. We'll ignore the other tabs and click directly on ``Response``.
What you should see in the ``Preview`` pane is the rendered HTML-code,
that is exactly what we saw when we called ``view(response)`` in the
shell. Accordingly the ``type`` of the request in the log is ``html``.
The other requests have types like ``css`` or ``js``, but what
interests us is the one request called ``quotes?page=1`` with the
type ``json``.
What you should see in the ``Preview`` pane is the rendered HTML-code,
that is exactly what we saw when we called ``view(response)`` in the
shell. Accordingly the ``type`` of the request in the log is ``html``.
The other requests have types like ``css`` or ``js``, but what
interests us is the one request called ``quotes?page=1`` with the
type ``json``.
If we click on this request, we see that the request URL is
If we click on this request, we see that the request URL is
``http://quotes.toscrape.com/api/quotes?page=1`` and the response
is a JSON-object that contains our quotes. We can also right-click
on the request and open ``Open in new tab`` to get a better overview.
on the request and open ``Open in new tab`` to get a better overview.
.. image:: _images/network_03.png
:width: 777
:height: 375
:alt: JSON-object returned from the quotes.toscrape API
With this response we can now easily parse the JSON-object and
With this response we can now easily parse the JSON-object and
also request each page to get every quote on the site::
import scrapy
@ -255,17 +255,17 @@ also request each page to get every quote on the site::
yield {"quote": quote["text"]}
if data["has_next"]:
self.page += 1
url = "http://quotes.toscrape.com/api/quotes?page={}".format(self.page)
url = f"http://quotes.toscrape.com/api/quotes?page={self.page}"
yield scrapy.Request(url=url, callback=self.parse)
This spider starts at the first page of the quotes-API. With each
response, we parse the ``response.text`` and assign it to ``data``.
This lets us operate on the JSON-object like on a Python dictionary.
This spider starts at the first page of the quotes-API. With each
response, we parse the ``response.text`` and assign it to ``data``.
This lets us operate on the JSON-object like on a Python dictionary.
We iterate through the ``quotes`` and print out the ``quote["text"]``.
If the handy ``has_next`` element is ``true`` (try loading
If the handy ``has_next`` element is ``true`` (try loading
`quotes.toscrape.com/api/quotes?page=10`_ in your browser or a
page-number greater than 10), we increment the ``page`` attribute
and ``yield`` a new request, inserting the incremented page-number
page-number greater than 10), we increment the ``page`` attribute
and ``yield`` a new request, inserting the incremented page-number
into our ``url``.
.. _requests-from-curl:
@ -289,11 +289,16 @@ request::
"://quotes.toscrape.com/scroll' -H 'Cache-Control: max-age=0'")
Alternatively, if you want to know the arguments needed to recreate that
request you can use the :func:`scrapy.utils.curl.curl_to_request_kwargs`
function to get a dictionary with the equivalent arguments.
request you can use the :func:`~scrapy.utils.curl.curl_to_request_kwargs`
function to get a dictionary with the equivalent arguments:
.. autofunction:: scrapy.utils.curl.curl_to_request_kwargs
Note that to translate a cURL command into a Scrapy request,
you may use `curl2scrapy <https://michael-shub.github.io/curl2scrapy/>`_.
As you can see, with a few inspections in the `Network`-tool we
were able to easily replicate the dynamic requests of the scrolling
were able to easily replicate the dynamic requests of the scrolling
functionality of the page. Crawling dynamic pages can be quite
daunting and pages can be very complex, but it (mostly) boils down
to identifying the correct request and replicating it in your spider.

79
docs/topics/downloader-middleware.rst
View File

@ -202,6 +202,16 @@ CookiesMiddleware
sends them back on subsequent requests (from that spider), just like web
browsers do.
.. caution:: When non-UTF8 encoded byte sequences are passed to a
:class:`~scrapy.http.Request`, the ``CookiesMiddleware`` will log
a warning. Refer to :ref:`topics-logging-advanced-customization`
to customize the logging behaviour.
.. caution:: Cookies set via the ``Cookie`` header are not considered by the
:ref:`cookies-mw`. If you need to set cookies for a request, use the
:class:`Request.cookies <scrapy.http.Request>` parameter. This is a known
current limitation that is being worked on.
The following settings can be used to configure the cookie middleware:
* :setting:`COOKIES_ENABLED`
@ -212,8 +222,6 @@ The following settings can be used to configure the cookie middleware:
Multiple cookie sessions per spider
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. versionadded:: 0.15
There is support for keeping multiple cookie sessions per spider by using the
:reqmeta:`cookiejar` Request meta key. By default it uses a single cookie jar
(session), but you can pass an identifier to use different ones.
@ -470,8 +478,6 @@ DBM storage backend
.. class:: DbmCacheStorage
.. versionadded:: 0.13
A DBM_ storage backend is also available for the HTTP cache middleware.
By default, it uses the :mod:`dbm`, but you can change it with the
@ -544,15 +550,10 @@ settings:
HTTPCACHE_ENABLED
^^^^^^^^^^^^^^^^^
.. versionadded:: 0.11
Default: ``False``
Whether the HTTP cache will be enabled.
.. versionchanged:: 0.11
Before 0.11, :setting:`HTTPCACHE_DIR` was used to enable cache.
.. setting:: HTTPCACHE_EXPIRATION_SECS
HTTPCACHE_EXPIRATION_SECS
@ -565,9 +566,6 @@ Expiration time for cached requests, in seconds.
Cached requests older than this time will be re-downloaded. If zero, cached
requests will never expire.
.. versionchanged:: 0.11
Before 0.11, zero meant cached requests always expire.
.. setting:: HTTPCACHE_DIR
HTTPCACHE_DIR
@ -584,8 +582,6 @@ project data dir. For more info see: :ref:`topics-project-structure`.
HTTPCACHE_IGNORE_HTTP_CODES
^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. versionadded:: 0.10
Default: ``[]``
Don't cache response with these HTTP codes.
@ -604,8 +600,6 @@ If enabled, requests not found in the cache will be ignored instead of downloade
HTTPCACHE_IGNORE_SCHEMES
^^^^^^^^^^^^^^^^^^^^^^^^
.. versionadded:: 0.10
Default: ``['file']``
Don't cache responses with these URI schemes.
@ -624,8 +618,6 @@ The class which implements the cache storage backend.
HTTPCACHE_DBM_MODULE
^^^^^^^^^^^^^^^^^^^^
.. versionadded:: 0.13
Default: ``'dbm'``
The database module to use in the :ref:`DBM storage backend
@ -636,8 +628,6 @@ The database module to use in the :ref:`DBM storage backend
HTTPCACHE_POLICY
^^^^^^^^^^^^^^^^
.. versionadded:: 0.18
Default: ``'scrapy.extensions.httpcache.DummyPolicy'``
The class which implements the cache policy.
@ -647,8 +637,6 @@ The class which implements the cache policy.
HTTPCACHE_GZIP
^^^^^^^^^^^^^^
.. versionadded:: 1.0
Default: ``False``
If enabled, will compress all cached data with gzip.
@ -659,8 +647,6 @@ This setting is specific to the Filesystem backend.
HTTPCACHE_ALWAYS_STORE
^^^^^^^^^^^^^^^^^^^^^^
.. versionadded:: 1.1
Default: ``False``
If enabled, will cache pages unconditionally.
@ -679,8 +665,6 @@ responses you feed to the cache middleware.
HTTPCACHE_IGNORE_RESPONSE_CACHE_CONTROLS
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. versionadded:: 1.1
Default: ``[]``
List of Cache-Control directives in responses to be ignored.
@ -705,11 +689,14 @@ HttpCompressionMiddleware
This middleware allows compressed (gzip, deflate) traffic to be
sent/received from web sites.
This middleware also supports decoding `brotli-compressed`_ responses,
provided `brotlipy`_ is installed.
This middleware also supports decoding `brotli-compressed`_ as well as
`zstd-compressed`_ responses, provided that `brotlipy`_ or `zstandard`_ is
installed, respectively.
.. _brotli-compressed: https://www.ietf.org/rfc/rfc7932.txt
.. _brotlipy: https://pypi.org/project/brotlipy/
.. _zstd-compressed: https://www.ietf.org/rfc/rfc8478.txt
.. _zstandard: https://pypi.org/project/zstandard/
HttpCompressionMiddleware Settings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@ -730,8 +717,6 @@ HttpProxyMiddleware
.. module:: scrapy.downloadermiddlewares.httpproxy
:synopsis: Http Proxy Middleware
.. versionadded:: 0.8
.. reqmeta:: proxy
.. class:: HttpProxyMiddleware
@ -739,7 +724,7 @@ HttpProxyMiddleware
This middleware sets the HTTP proxy to use for requests, by setting the
``proxy`` meta value for :class:`~scrapy.http.Request` objects.
Like the Python standard library modules `urllib`_ and `urllib2`_, it obeys
Like the Python standard library module :mod:`urllib.request`, it obeys
the following environment variables:
* ``http_proxy``
@ -751,9 +736,6 @@ HttpProxyMiddleware
Keep in mind this value will take precedence over ``http_proxy``/``https_proxy``
environment variables, and it will also ignore ``no_proxy`` environment variable.
.. _urllib: https://docs.python.org/2/library/urllib.html
.. _urllib2: https://docs.python.org/2/library/urllib2.html
RedirectMiddleware
------------------
@ -815,8 +797,6 @@ RedirectMiddleware settings
REDIRECT_ENABLED
^^^^^^^^^^^^^^^^
.. versionadded:: 0.13
Default: ``True``
Whether the Redirect middleware will be enabled.
@ -829,6 +809,7 @@ REDIRECT_MAX_TIMES
Default: ``20``
The maximum number of redirections that will be followed for a single request.
After this maximum, the request's response is returned as is.
MetaRefreshMiddleware
---------------------
@ -857,8 +838,6 @@ MetaRefreshMiddleware settings
METAREFRESH_ENABLED
^^^^^^^^^^^^^^^^^^^
.. versionadded:: 0.17
Default: ``True``
Whether the Meta Refresh middleware will be enabled.
@ -913,6 +892,11 @@ settings (see the settings documentation for more info):
If :attr:`Request.meta <scrapy.http.Request.meta>` has ``dont_retry`` key
set to True, the request will be ignored by this middleware.
To retry requests from a spider callback, you can use the
:func:`get_retry_request` function:
.. autofunction:: get_retry_request
RetryMiddleware Settings
~~~~~~~~~~~~~~~~~~~~~~~~
@ -921,8 +905,6 @@ RetryMiddleware Settings
RETRY_ENABLED
^^^^^^^^^^^^^
.. versionadded:: 0.13
Default: ``True``
Whether the Retry middleware will be enabled.
@ -955,6 +937,18 @@ In some cases you may want to add 400 to :setting:`RETRY_HTTP_CODES` because
it is a common code used to indicate server overload. It is not included by
default because HTTP specs say so.
.. setting:: RETRY_PRIORITY_ADJUST
RETRY_PRIORITY_ADJUST
---------------------
Default: ``-1``
Adjust retry request priority relative to original request:
- a positive priority adjust means higher priority.
- **a negative priority adjust (default) means lower priority.**
.. _topics-dlmw-robots:
@ -1036,8 +1030,7 @@ Scrapy uses this parser by default.
RobotFileParser
~~~~~~~~~~~~~~~
Based on `RobotFileParser
<https://docs.python.org/3.7/library/urllib.robotparser.html>`_:
Based on :class:`~urllib.robotparser.RobotFileParser`:
* is Python's built-in robots.txt_ parser
@ -1177,8 +1170,6 @@ AjaxCrawlMiddleware Settings
AJAXCRAWL_ENABLED
^^^^^^^^^^^^^^^^^
.. versionadded:: 0.21
Default: ``False``
Whether the AjaxCrawlMiddleware will be enabled. You may want to

30
docs/topics/dynamic-content.rst
View File

@ -104,6 +104,9 @@ If you get the expected response `sometimes`, but not always, the issue is
probably not your request, but the target server. The target server might be
buggy, overloaded, or :ref:`banning <bans>` some of your requests.
Note that to translate a cURL command into a Scrapy request,
you may use `curl2scrapy <https://michael-shub.github.io/curl2scrapy/>`_.
.. _topics-handling-response-formats:
Handling different response formats
@ -115,7 +118,7 @@ data from it depends on the type of response:
- If the response is HTML or XML, use :ref:`selectors
<topics-selectors>` as usual.
- If the response is JSON, use `json.loads`_ to load the desired data from
- If the response is JSON, use :func:`json.loads` to load the desired data from
:attr:`response.text <scrapy.http.TextResponse.text>`::
data = json.loads(response.text)
@ -130,8 +133,9 @@ data from it depends on the type of response:
- If the response is JavaScript, or HTML with a ``<script/>`` element
containing the desired data, see :ref:`topics-parsing-javascript`.
- If the response is CSS, use a `regular expression`_ to extract the desired
data from :attr:`response.text <scrapy.http.TextResponse.text>`.
- If the response is CSS, use a :doc:`regular expression <library/re>` to
extract the desired data from
:attr:`response.text <scrapy.http.TextResponse.text>`.
.. _topics-parsing-images:
@ -168,8 +172,9 @@ JavaScript code:
Once you have a string with the JavaScript code, you can extract the desired
data from it:
- You might be able to use a `regular expression`_ to extract the desired
data in JSON format, which you can then parse with `json.loads`_.
- You might be able to use a :doc:`regular expression <library/re>` to
extract the desired data in JSON format, which you can then parse with
:func:`json.loads`.
For example, if the JavaScript code contains a separate line like
``var data = {"field": "value"};`` you can extract that data as follows:
@ -179,6 +184,18 @@ data from it:
>>> json.loads(json_data)
{'field': 'value'}
- chompjs_ provides an API to parse JavaScript objects into a :class:`dict`.
For example, if the JavaScript code contains
``var data = {field: "value", secondField: "second value"};``
you can extract that data as follows:
>>> import chompjs
>>> javascript = response.css('script::text').get()
>>> data = chompjs.parse_js_object(javascript)
>>> data
{'field': 'value', 'secondField': 'second value'}
- Otherwise, use js2xml_ to convert the JavaScript code into an XML document
that you can parse using :ref:`selectors <topics-selectors>`.
@ -236,14 +253,13 @@ along with `scrapy-selenium`_ for seamless integration.
.. _AJAX: https://en.wikipedia.org/wiki/Ajax_%28programming%29
.. _chompjs: https://github.com/Nykakin/chompjs
.. _CSS: https://en.wikipedia.org/wiki/Cascading_Style_Sheets
.. _curl: https://curl.haxx.se/
.. _headless browser: https://en.wikipedia.org/wiki/Headless_browser
.. _JavaScript: https://en.wikipedia.org/wiki/JavaScript
.. _js2xml: https://github.com/scrapinghub/js2xml
.. _json.loads: https://docs.python.org/3/library/json.html#json.loads
.. _pytesseract: https://github.com/madmaze/pytesseract
.. _regular expression: https://docs.python.org/3/library/re.html
.. _scrapy-selenium: https://github.com/clemfromspace/scrapy-selenium
.. _scrapy-splash: https://github.com/scrapy-plugins/scrapy-splash
.. _Selenium: https://www.selenium.dev/

18
docs/topics/email.rst
View File

@ -7,7 +7,7 @@ Sending e-mail
.. module:: scrapy.mail
:synopsis: Email sending facility
Although Python makes sending e-mails relatively easy via the `smtplib`_
Although Python makes sending e-mails relatively easy via the :mod:`smtplib`
library, Scrapy provides its own facility for sending e-mails which is very
easy to use and it's implemented using :doc:`Twisted non-blocking IO
<twisted:core/howto/defer-intro>`, to avoid interfering with the non-blocking
@ -15,8 +15,6 @@ IO of the crawler. It also provides a simple API for sending attachments and
it's very easy to configure, with a few :ref:`settings
<topics-email-settings>`.
.. _smtplib: https://docs.python.org/2/library/smtplib.html
Quick example
=============
@ -64,10 +62,10 @@ rest of the framework.
:type smtpport: int
:param smtptls: enforce using SMTP STARTTLS
:type smtptls: boolean
:type smtptls: bool
:param smtpssl: enforce using a secure SSL connection
:type smtpssl: boolean
:type smtpssl: bool
.. classmethod:: from_settings(settings)
@ -81,14 +79,14 @@ rest of the framework.
Send email to the given recipients.
:param to: the e-mail recipients
:type to: str or list of str
:param to: the e-mail recipients as a string or as a list of strings
:type to: str or list
:param subject: the subject of the e-mail
:type subject: str
:param cc: the e-mails to CC
:type cc: str or list of str
:param cc: the e-mails to CC as a string or as a list of strings
:type cc: str or list
:param body: the e-mail body
:type body: str
@ -98,7 +96,7 @@ rest of the framework.
appear on the e-mail's attachment, ``mimetype`` is the mimetype of the
attachment and ``file_object`` is a readable file object with the
contents of the attachment
:type attachs: iterable
:type attachs: collections.abc.Iterable
:param mimetype: the MIME type of the e-mail
:type mimetype: str

58
docs/topics/exceptions.rst
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@ -14,13 +14,6 @@ Built-in Exceptions reference
Here's a list of all exceptions included in Scrapy and their usage.
DropItem
--------
.. exception:: DropItem
The exception that must be raised by item pipeline stages to stop processing an
Item. For more information see :ref:`topics-item-pipeline`.
CloseSpider
-----------
@ -47,6 +40,14 @@ DontCloseSpider
This exception can be raised in a :signal:`spider_idle` signal handler to
prevent the spider from being closed.
DropItem
--------
.. exception:: DropItem
The exception that must be raised by item pipeline stages to stop processing an
Item. For more information see :ref:`topics-item-pipeline`.
IgnoreRequest
-------------
@ -63,10 +64,10 @@ NotConfigured
This exception can be raised by some components to indicate that they will
remain disabled. Those components include:
* Extensions
* Item pipelines
* Downloader middlewares
* Spider middlewares
- Extensions
- Item pipelines
- Downloader middlewares
- Spider middlewares
The exception must be raised in the component's ``__init__`` method.
@ -77,3 +78,38 @@ NotSupported
This exception is raised to indicate an unsupported feature.
StopDownload
-------------
.. versionadded:: 2.2
.. exception:: StopDownload(fail=True)
Raised from a :class:`~scrapy.signals.bytes_received` or :class:`~scrapy.signals.headers_received`
signal handler to indicate that no further bytes should be downloaded for a response.
The ``fail`` boolean parameter controls which method will handle the resulting
response:
* If ``fail=True`` (default), the request errback is called. The response object is
available as the ``response`` attribute of the ``StopDownload`` exception,
which is in turn stored as the ``value`` attribute of the received
:class:`~twisted.python.failure.Failure` object. This means that in an errback
defined as ``def errback(self, failure)``, the response can be accessed though
``failure.value.response``.
* If ``fail=False``, the request callback is called instead.
In both cases, the response could have its body truncated: the body contains
all bytes received up until the exception is raised, including the bytes
received in the signal handler that raises the exception. Also, the response
object is marked with ``"download_stopped"`` in its :attr:`Response.flags`
attribute.
.. note:: ``fail`` is a keyword-only parameter, i.e. raising
``StopDownload(False)`` or ``StopDownload(True)`` will raise
a :class:`TypeError`.
See the documentation for the :class:`~scrapy.signals.bytes_received` and
:class:`~scrapy.signals.headers_received` signals
and the :ref:`topics-stop-response-download` topic for additional information and examples.

98
docs/topics/exporters.rst
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@ -40,6 +40,7 @@ Here you can see an :doc:`Item Pipeline <item-pipeline>` which uses multiple
Item Exporters to group scraped items to different files according to the
value of one of their fields::
from itemadapter import ItemAdapter
from scrapy.exporters import XmlItemExporter
class PerYearXmlExportPipeline:
@ -49,17 +50,19 @@ value of one of their fields::
self.year_to_exporter = {}
def close_spider(self, spider):
for exporter in self.year_to_exporter.values():
for exporter, xml_file in self.year_to_exporter.values():
exporter.finish_exporting()
xml_file.close()
def _exporter_for_item(self, item):
year = item['year']
adapter = ItemAdapter(item)
year = adapter['year']
if year not in self.year_to_exporter:
f = open('{}.xml'.format(year), 'wb')
exporter = XmlItemExporter(f)
xml_file = open(f'{year}.xml', 'wb')
exporter = XmlItemExporter(xml_file)
exporter.start_exporting()
self.year_to_exporter[year] = exporter
return self.year_to_exporter[year]
self.year_to_exporter[year] = (exporter, xml_file)
return self.year_to_exporter[year][0]
def process_item(self, item, spider):
exporter = self._exporter_for_item(item)
@ -96,7 +99,7 @@ Example::
import scrapy
def serialize_price(value):
return '$ %s' % str(value)
return f'$ {str(value)}'
class Product(scrapy.Item):
name = scrapy.Field()
@ -120,8 +123,8 @@ Example::
def serialize_field(self, field, name, value):
if field == 'price':
return '$ %s' % str(value)
return super(Product, self).serialize_field(field, name, value)
return f'$ {str(value)}'
return super().serialize_field(field, name, value)
.. _topics-exporters-reference:
@ -164,12 +167,12 @@ BaseItemExporter
By default, this method looks for a serializer :ref:`declared in the item
field <topics-exporters-serializers>` and returns the result of applying
that serializer to the value. If no serializer is found, it returns the
value unchanged except for ``unicode`` values which are encoded to
``str`` using the encoding declared in the :attr:`encoding` attribute.
value unchanged.
:param field: the field being serialized. If a raw dict is being
exported (not :class:`~.Item`) *field* value is an empty dict.
:type field: :class:`~scrapy.item.Field` object or an empty dict
:param field: the field being serialized. If the source :ref:`item object
<item-types>` does not define field metadata, *field* is an empty
:class:`dict`.
:type field: :class:`~scrapy.item.Field` object or a :class:`dict` instance
:param name: the name of the field being serialized
:type name: str
@ -192,14 +195,17 @@ BaseItemExporter
.. attribute:: fields_to_export
A list with the name of the fields that will be exported, or None if you
want to export all fields. Defaults to None.
A list with the name of the fields that will be exported, or ``None`` if
you want to export all fields. Defaults to ``None``.
Some exporters (like :class:`CsvItemExporter`) respect the order of the
fields defined in this attribute.
Some exporters may require fields_to_export list in order to export the
data properly when spiders return dicts (not :class:`~Item` instances).
When using :ref:`item objects <item-types>` that do not expose all their
possible fields, exporters that do not support exporting a different
subset of fields per item will only export the fields found in the first
item exported. Use ``fields_to_export`` to define all the fields to be
exported.
.. attribute:: export_empty_fields
@ -211,10 +217,7 @@ BaseItemExporter
.. attribute:: encoding
The encoding that will be used to encode unicode values. This only
affects unicode values (which are always serialized to str using this
encoding). Other value types are passed unchanged to the specific
serialization library.
The output character encoding.
.. attribute:: indent
@ -236,9 +239,9 @@ PythonItemExporter
XmlItemExporter
---------------
.. class:: XmlItemExporter(file, item_element='item', root_element='items', \**kwargs)
.. class:: XmlItemExporter(file, item_element='item', root_element='items', **kwargs)
Exports Items in XML format to the specified file object.
Exports items in XML format to the specified file object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -290,9 +293,9 @@ XmlItemExporter
CsvItemExporter
---------------
.. class:: CsvItemExporter(file, include_headers_line=True, join_multivalued=',', \**kwargs)
.. class:: CsvItemExporter(file, include_headers_line=True, join_multivalued=',', errors=None, **kwargs)
Exports Items in CSV format to the given file-like object. If the
Exports items in CSV format to the given file-like object. If the
:attr:`fields_to_export` attribute is set, it will be used to define the
CSV columns and their order. The :attr:`export_empty_fields` attribute has
no effect on this exporter.
@ -303,15 +306,20 @@ CsvItemExporter
:param include_headers_line: If enabled, makes the exporter output a header
line with the field names taken from
:attr:`BaseItemExporter.fields_to_export` or the first exported item fields.
:type include_headers_line: boolean
:type include_headers_line: bool
:param join_multivalued: The char (or chars) that will be used for joining
multi-valued fields, if found.
:type include_headers_line: str
:param errors: The optional string that specifies how encoding and decoding
errors are to be handled. For more information see
:class:`io.TextIOWrapper`.
:type errors: str
The additional keyword arguments of this ``__init__`` method are passed to the
:class:`BaseItemExporter` ``__init__`` method, and the leftover arguments to the
`csv.writer`_ ``__init__`` method, so you can use any ``csv.writer`` ``__init__`` method
:func:`csv.writer` function, so you can use any :func:`csv.writer` function
argument to customize this exporter.
A typical output of this exporter would be::
@ -320,14 +328,12 @@ CsvItemExporter
Color TV,1200
DVD player,200
.. _csv.writer: https://docs.python.org/2/library/csv.html#csv.writer
PickleItemExporter
------------------
.. class:: PickleItemExporter(file, protocol=0, \**kwargs)
.. class:: PickleItemExporter(file, protocol=0, **kwargs)
Exports Items in pickle format to the given file-like object.
Exports items in pickle format to the given file-like object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -335,21 +341,19 @@ PickleItemExporter
:param protocol: The pickle protocol to use.
:type protocol: int
For more information, refer to the `pickle module documentation`_.
For more information, see :mod:`pickle`.
The additional keyword arguments of this ``__init__`` method are passed to the
:class:`BaseItemExporter` ``__init__`` method.
Pickle isn't a human readable format, so no output examples are provided.
.. _pickle module documentation: https://docs.python.org/2/library/pickle.html
PprintItemExporter
------------------
.. class:: PprintItemExporter(file, \**kwargs)
.. class:: PprintItemExporter(file, **kwargs)
Exports Items in pretty print format to the specified file object.
Exports items in pretty print format to the specified file object.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -367,13 +371,13 @@ PprintItemExporter
JsonItemExporter
----------------
.. class:: JsonItemExporter(file, \**kwargs)
.. class:: JsonItemExporter(file, **kwargs)
Exports Items in JSON format to the specified file-like object, writing all
Exports items in JSON format to the specified file-like object, writing all
objects as a list of objects. The additional ``__init__`` method arguments are
passed to the :class:`BaseItemExporter` ``__init__`` method, and the leftover
arguments to the `JSONEncoder`_ ``__init__`` method, so you can use any
`JSONEncoder`_ ``__init__`` method argument to customize this exporter.
arguments to the :class:`~json.JSONEncoder` ``__init__`` method, so you can use any
:class:`~json.JSONEncoder` ``__init__`` method argument to customize this exporter.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -393,18 +397,16 @@ JsonItemExporter
stream-friendly format, consider using :class:`JsonLinesItemExporter`
instead, or splitting the output in multiple chunks.
.. _JSONEncoder: https://docs.python.org/2/library/json.html#json.JSONEncoder
JsonLinesItemExporter
---------------------
.. class:: JsonLinesItemExporter(file, \**kwargs)
.. class:: JsonLinesItemExporter(file, **kwargs)
Exports Items in JSON format to the specified file-like object, writing one
Exports items in JSON format to the specified file-like object, writing one
JSON-encoded item per line. The additional ``__init__`` method arguments are passed
to the :class:`BaseItemExporter` ``__init__`` method, and the leftover arguments to
the `JSONEncoder`_ ``__init__`` method, so you can use any `JSONEncoder`_
``__init__`` method argument to customize this exporter.
the :class:`~json.JSONEncoder` ``__init__`` method, so you can use any
:class:`~json.JSONEncoder` ``__init__`` method argument to customize this exporter.
:param file: the file-like object to use for exporting the data. Its ``write`` method should
accept ``bytes`` (a disk file opened in binary mode, a ``io.BytesIO`` object, etc)
@ -417,8 +419,6 @@ JsonLinesItemExporter
Unlike the one produced by :class:`JsonItemExporter`, the format produced by
this exporter is well suited for serializing large amounts of data.
.. _JSONEncoder: https://docs.python.org/2/library/json.html#json.JSONEncoder
MarshalItemExporter
-------------------

22
docs/topics/extensions.rst
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@ -7,8 +7,7 @@ Extensions
The extensions framework provides a mechanism for inserting your own
custom functionality into Scrapy.
Extensions are just regular classes that are instantiated at Scrapy startup,
when extensions are initialized.
Extensions are just regular classes.
Extension settings
==================
@ -27,8 +26,8 @@ Loading & activating extensions
===============================
Extensions are loaded and activated at startup by instantiating a single
instance of the extension class. Therefore, all the extension initialization
code must be performed in the class ``__init__`` method.
instance of the extension class per spider being run. All the extension
initialization code must be performed in the class ``__init__`` method.
To make an extension available, add it to the :setting:`EXTENSIONS` setting in
your Scrapy settings. In :setting:`EXTENSIONS`, each extension is represented
@ -257,6 +256,12 @@ settings:
* :setting:`CLOSESPIDER_PAGECOUNT`
* :setting:`CLOSESPIDER_ERRORCOUNT`
.. note::
When a certain closing condition is met, requests which are
currently in the downloader queue (up to :setting:`CONCURRENT_REQUESTS`
requests) are still processed.
.. setting:: CLOSESPIDER_TIMEOUT
CLOSESPIDER_TIMEOUT
@ -279,8 +284,6 @@ Default: ``0``
An integer which specifies a number of items. If the spider scrapes more than
that amount and those items are passed by the item pipeline, the
spider will be closed with the reason ``closespider_itemcount``.
Requests which are currently in the downloader queue (up to
:setting:`CONCURRENT_REQUESTS` requests) are still processed.
If zero (or non set), spiders won't be closed by number of passed items.
.. setting:: CLOSESPIDER_PAGECOUNT
@ -288,8 +291,6 @@ If zero (or non set), spiders won't be closed by number of passed items.
CLOSESPIDER_PAGECOUNT
"""""""""""""""""""""
.. versionadded:: 0.11
Default: ``0``
An integer which specifies the maximum number of responses to crawl. If the spider
@ -302,8 +303,6 @@ number of crawled responses.
CLOSESPIDER_ERRORCOUNT
""""""""""""""""""""""
.. versionadded:: 0.11
Default: ``0``
An integer which specifies the maximum number of errors to receive before
@ -364,7 +363,7 @@ Debugger extension
.. class:: Debugger
Invokes a `Python debugger`_ inside a running Scrapy process when a `SIGUSR2`_
Invokes a :doc:`Python debugger <library/pdb>` inside a running Scrapy process when a `SIGUSR2`_
signal is received. After the debugger is exited, the Scrapy process continues
running normally.
@ -372,5 +371,4 @@ For more info see `Debugging in Python`_.
This extension only works on POSIX-compliant platforms (i.e. not Windows).
.. _Python debugger: https://docs.python.org/2/library/pdb.html
.. _Debugging in Python: https://pythonconquerstheuniverse.wordpress.com/2009/09/10/debugging-in-python/

358
docs/topics/feed-exports.rst
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@ -4,8 +4,6 @@
Feed exports
============
.. versionadded:: 0.10
One of the most frequently required features when implementing scrapers is
being able to store the scraped data properly and, quite often, that means
generating an "export file" with the scraped data (commonly called "export
@ -23,10 +21,10 @@ Serialization formats
For serializing the scraped data, the feed exports use the :ref:`Item exporters
<topics-exporters>`. These formats are supported out of the box:
* :ref:`topics-feed-format-json`
* :ref:`topics-feed-format-jsonlines`
* :ref:`topics-feed-format-csv`
* :ref:`topics-feed-format-xml`
- :ref:`topics-feed-format-json`
- :ref:`topics-feed-format-jsonlines`
- :ref:`topics-feed-format-csv`
- :ref:`topics-feed-format-xml`
But you can also extend the supported format through the
:setting:`FEED_EXPORTERS` setting.
@ -36,54 +34,58 @@ But you can also extend the supported format through the
JSON
----
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``json``
* Exporter used: :class:`~scrapy.exporters.JsonItemExporter`
* See :ref:`this warning <json-with-large-data>` if you're using JSON with
large feeds.
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``json``
- Exporter used: :class:`~scrapy.exporters.JsonItemExporter`
- See :ref:`this warning <json-with-large-data>` if you're using JSON with
large feeds.
.. _topics-feed-format-jsonlines:
JSON lines
----------
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``jsonlines``
* Exporter used: :class:`~scrapy.exporters.JsonLinesItemExporter`
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``jsonlines``
- Exporter used: :class:`~scrapy.exporters.JsonLinesItemExporter`
.. _topics-feed-format-csv:
CSV
---
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``csv``
* Exporter used: :class:`~scrapy.exporters.CsvItemExporter`
* To specify columns to export and their order use
:setting:`FEED_EXPORT_FIELDS`. Other feed exporters can also use this
option, but it is important for CSV because unlike many other export
formats CSV uses a fixed header.
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``csv``
- Exporter used: :class:`~scrapy.exporters.CsvItemExporter`
- To specify columns to export and their order use
:setting:`FEED_EXPORT_FIELDS`. Other feed exporters can also use this
option, but it is important for CSV because unlike many other export
formats CSV uses a fixed header.
.. _topics-feed-format-xml:
XML
---
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``xml``
* Exporter used: :class:`~scrapy.exporters.XmlItemExporter`
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``xml``
- Exporter used: :class:`~scrapy.exporters.XmlItemExporter`
.. _topics-feed-format-pickle:
Pickle
------
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``pickle``
* Exporter used: :class:`~scrapy.exporters.PickleItemExporter`
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``pickle``
- Exporter used: :class:`~scrapy.exporters.PickleItemExporter`
.. _topics-feed-format-marshal:
Marshal
-------
* Value for the ``format`` key in the :setting:`FEEDS` setting: ``marshal``
* Exporter used: :class:`~scrapy.exporters.MarshalItemExporter`
- Value for the ``format`` key in the :setting:`FEEDS` setting: ``marshal``
- Exporter used: :class:`~scrapy.exporters.MarshalItemExporter`
.. _topics-feed-storage:
@ -97,10 +99,11 @@ storage backend types which are defined by the URI scheme.
The storages backends supported out of the box are:
* :ref:`topics-feed-storage-fs`
* :ref:`topics-feed-storage-ftp`
* :ref:`topics-feed-storage-s3` (requires botocore_)
* :ref:`topics-feed-storage-stdout`
- :ref:`topics-feed-storage-fs`
- :ref:`topics-feed-storage-ftp`
- :ref:`topics-feed-storage-s3` (requires botocore_)
- :ref:`topics-feed-storage-gcs` (requires `google-cloud-storage`_)
- :ref:`topics-feed-storage-stdout`
Some storage backends may be unavailable if the required external libraries are
not available. For example, the S3 backend is only available if the botocore_
@ -115,8 +118,8 @@ Storage URI parameters
The storage URI can also contain parameters that get replaced when the feed is
being created. These parameters are:
* ``%(time)s`` - gets replaced by a timestamp when the feed is being created
* ``%(name)s`` - gets replaced by the spider name
- ``%(time)s`` - gets replaced by a timestamp when the feed is being created
- ``%(name)s`` - gets replaced by the spider name
Any other named parameter gets replaced by the spider attribute of the same
name. For example, ``%(site_id)s`` would get replaced by the ``spider.site_id``
@ -124,13 +127,16 @@ attribute the moment the feed is being created.
Here are some examples to illustrate:
* Store in FTP using one directory per spider:
- Store in FTP using one directory per spider:
* ``ftp://user:password@ftp.example.com/scraping/feeds/%(name)s/%(time)s.json``
- ``ftp://user:password@ftp.example.com/scraping/feeds/%(name)s/%(time)s.json``
* Store in S3 using one directory per spider:
- Store in S3 using one directory per spider:
* ``s3://mybucket/scraping/feeds/%(name)s/%(time)s.json``
- ``s3://mybucket/scraping/feeds/%(name)s/%(time)s.json``
.. note:: :ref:`Spider arguments <spiderargs>` become spider attributes, hence
they can also be used as storage URI parameters.
.. _topics-feed-storage-backends:
@ -145,9 +151,9 @@ Local filesystem
The feeds are stored in the local filesystem.
* URI scheme: ``file``
* Example URI: ``file:///tmp/export.csv``
* Required external libraries: none
- URI scheme: ``file``
- Example URI: ``file:///tmp/export.csv``
- Required external libraries: none
Note that for the local filesystem storage (only) you can omit the scheme if
you specify an absolute path like ``/tmp/export.csv``. This only works on Unix
@ -160,15 +166,18 @@ FTP
The feeds are stored in a FTP server.
* URI scheme: ``ftp``
* Example URI: ``ftp://user:pass@ftp.example.com/path/to/export.csv``
* Required external libraries: none
- URI scheme: ``ftp``
- Example URI: ``ftp://user:pass@ftp.example.com/path/to/export.csv``
- Required external libraries: none
FTP supports two different connection modes: `active or passive
<https://stackoverflow.com/a/1699163>`_. Scrapy uses the passive connection
mode by default. To use the active connection mode instead, set the
:setting:`FEED_STORAGE_FTP_ACTIVE` setting to ``True``.
This storage backend uses :ref:`delayed file delivery <delayed-file-delivery>`.
.. _topics-feed-storage-s3:
S3
@ -176,23 +185,57 @@ S3
The feeds are stored on `Amazon S3`_.
* URI scheme: ``s3``
* Example URIs:
- URI scheme: ``s3``
* ``s3://mybucket/path/to/export.csv``
* ``s3://aws_key:aws_secret@mybucket/path/to/export.csv``
- Example URIs:
* Required external libraries: `botocore`_
- ``s3://mybucket/path/to/export.csv``
- ``s3://aws_key:aws_secret@mybucket/path/to/export.csv``
- Required external libraries: `botocore`_ >= 1.4.87
The AWS credentials can be passed as user/password in the URI, or they can be
passed through the following settings:
* :setting:`AWS_ACCESS_KEY_ID`
* :setting:`AWS_SECRET_ACCESS_KEY`
- :setting:`AWS_ACCESS_KEY_ID`
- :setting:`AWS_SECRET_ACCESS_KEY`
You can also define a custom ACL for exported feeds using this setting:
* :setting:`FEED_STORAGE_S3_ACL`
- :setting:`FEED_STORAGE_S3_ACL`
This storage backend uses :ref:`delayed file delivery <delayed-file-delivery>`.
.. _topics-feed-storage-gcs:
Google Cloud Storage (GCS)
--------------------------
.. versionadded:: 2.3
The feeds are stored on `Google Cloud Storage`_.
- URI scheme: ``gs``
- Example URIs:
- ``gs://mybucket/path/to/export.csv``
- Required external libraries: `google-cloud-storage`_.
For more information about authentication, please refer to `Google Cloud documentation <https://cloud.google.com/docs/authentication/production>`_.
You can set a *Project ID* and *Access Control List (ACL)* through the following settings:
- :setting:`FEED_STORAGE_GCS_ACL`
- :setting:`GCS_PROJECT_ID`
This storage backend uses :ref:`delayed file delivery <delayed-file-delivery>`.
.. _google-cloud-storage: https://cloud.google.com/storage/docs/reference/libraries#client-libraries-install-python
.. _topics-feed-storage-stdout:
@ -201,9 +244,29 @@ Standard output
The feeds are written to the standard output of the Scrapy process.
* URI scheme: ``stdout``
* Example URI: ``stdout:``
* Required external libraries: none
- URI scheme: ``stdout``
- Example URI: ``stdout:``
- Required external libraries: none
.. _delayed-file-delivery:
Delayed file delivery
---------------------
As indicated above, some of the described storage backends use delayed file
delivery.
These storage backends do not upload items to the feed URI as those items are
scraped. Instead, Scrapy writes items into a temporary local file, and only
once all the file contents have been written (i.e. at the end of the crawl) is
that file uploaded to the feed URI.
If you want item delivery to start earlier when using one of these storage
backends, use :setting:`FEED_EXPORT_BATCH_ITEM_COUNT` to split the output items
in multiple files, with the specified maximum item count per file. That way, as
soon as a file reaches the maximum item count, that file is delivered to the
feed URI, allowing item delivery to start way before the end of the crawl.
Settings
@ -211,15 +274,16 @@ Settings
These are the settings used for configuring the feed exports:
* :setting:`FEEDS` (mandatory)
* :setting:`FEED_EXPORT_ENCODING`
* :setting:`FEED_STORE_EMPTY`
* :setting:`FEED_EXPORT_FIELDS`
* :setting:`FEED_EXPORT_INDENT`
* :setting:`FEED_STORAGES`
* :setting:`FEED_STORAGE_FTP_ACTIVE`
* :setting:`FEED_STORAGE_S3_ACL`
* :setting:`FEED_EXPORTERS`
- :setting:`FEEDS` (mandatory)
- :setting:`FEED_EXPORT_ENCODING`
- :setting:`FEED_STORE_EMPTY`
- :setting:`FEED_EXPORT_FIELDS`
- :setting:`FEED_EXPORT_INDENT`
- :setting:`FEED_STORAGES`
- :setting:`FEED_STORAGE_FTP_ACTIVE`
- :setting:`FEED_STORAGE_S3_ACL`
- :setting:`FEED_EXPORTERS`
- :setting:`FEED_EXPORT_BATCH_ITEM_COUNT`
.. currentmodule:: scrapy.extensions.feedexport
@ -235,6 +299,7 @@ Default: ``{}``
A dictionary in which every key is a feed URI (or a :class:`pathlib.Path`
object) and each value is a nested dictionary containing configuration
parameters for the specific feed.
This setting is required for enabling the feed export feature.
See :ref:`topics-feed-storage-backends` for supported URI schemes.
@ -248,6 +313,9 @@ For instance::
'store_empty': False,
'fields': None,
'indent': 4,
'item_export_kwargs': {
'export_empty_fields': True,
},
},
'/home/user/documents/items.xml': {
'format': 'xml',
@ -261,16 +329,54 @@ For instance::
},
}
The following is a list of the accepted keys and the setting that is used
as a fallback value if that key is not provided for a specific feed definition.
.. _feed-options:
The following is a list of the accepted keys and the setting that is used
as a fallback value if that key is not provided for a specific feed definition:
- ``format``: the :ref:`serialization format <topics-feed-format>`.
This setting is mandatory, there is no fallback value.
- ``batch_item_count``: falls back to
:setting:`FEED_EXPORT_BATCH_ITEM_COUNT`.
.. versionadded:: 2.3.0
- ``encoding``: falls back to :setting:`FEED_EXPORT_ENCODING`.
- ``fields``: falls back to :setting:`FEED_EXPORT_FIELDS`.
- ``indent``: falls back to :setting:`FEED_EXPORT_INDENT`.
- ``item_export_kwargs``: :class:`dict` with keyword arguments for the corresponding :ref:`item exporter class <topics-exporters>`.
.. versionadded:: 2.4.0
- ``overwrite``: whether to overwrite the file if it already exists
(``True``) or append to its content (``False``).
The default value depends on the :ref:`storage backend
<topics-feed-storage-backends>`:
- :ref:`topics-feed-storage-fs`: ``False``
- :ref:`topics-feed-storage-ftp`: ``True``
.. note:: Some FTP servers may not support appending to files (the
``APPE`` FTP command).
- :ref:`topics-feed-storage-s3`: ``True`` (appending `is not supported
<https://forums.aws.amazon.com/message.jspa?messageID=540395>`_)
- :ref:`topics-feed-storage-stdout`: ``False`` (overwriting is not supported)
.. versionadded:: 2.4.0
- ``store_empty``: falls back to :setting:`FEED_STORE_EMPTY`.
- ``uri_params``: falls back to :setting:`FEED_URI_PARAMS`.
* ``format``: the serialization format to be used for the feed.
See :ref:`topics-feed-format` for possible values.
Mandatory, no fallback setting
* ``encoding``: falls back to :setting:`FEED_EXPORT_ENCODING`
* ``fields``: falls back to :setting:`FEED_EXPORT_FIELDS`
* ``indent``: falls back to :setting:`FEED_EXPORT_INDENT`
* ``store_empty``: falls back to :setting:`FEED_STORE_EMPTY`
.. setting:: FEED_EXPORT_ENCODING
@ -298,8 +404,8 @@ Example: ``FEED_EXPORT_FIELDS = ["foo", "bar", "baz"]``.
Use FEED_EXPORT_FIELDS option to define fields to export and their order.
When FEED_EXPORT_FIELDS is empty or None (default), Scrapy uses fields
defined in dicts or :class:`~.Item` subclasses a spider is yielding.
When FEED_EXPORT_FIELDS is empty or None (default), Scrapy uses the fields
defined in :ref:`item objects <topics-items>` yielded by your spider.
If an exporter requires a fixed set of fields (this is the case for
:ref:`CSV <topics-feed-format-csv>` export format) and FEED_EXPORT_FIELDS
@ -425,7 +531,117 @@ format in :setting:`FEED_EXPORTERS`. E.g., to disable the built-in CSV exporter
'csv': None,
}
.. setting:: FEED_EXPORT_BATCH_ITEM_COUNT
FEED_EXPORT_BATCH_ITEM_COUNT
----------------------------
.. versionadded:: 2.3.0
Default: ``0``
If assigned an integer number higher than ``0``, Scrapy generates multiple output files
storing up to the specified number of items in each output file.
When generating multiple output files, you must use at least one of the following
placeholders in the feed URI to indicate how the different output file names are
generated:
* ``%(batch_time)s`` - gets replaced by a timestamp when the feed is being created
(e.g. ``2020-03-28T14-45-08.237134``)
* ``%(batch_id)d`` - gets replaced by the 1-based sequence number of the batch.
Use :ref:`printf-style string formatting <python:old-string-formatting>` to
alter the number format. For example, to make the batch ID a 5-digit
number by introducing leading zeroes as needed, use ``%(batch_id)05d``
(e.g. ``3`` becomes ``00003``, ``123`` becomes ``00123``).
For instance, if your settings include::
FEED_EXPORT_BATCH_ITEM_COUNT = 100
And your :command:`crawl` command line is::
scrapy crawl spidername -o "dirname/%(batch_id)d-filename%(batch_time)s.json"
The command line above can generate a directory tree like::
->projectname
-->dirname
--->1-filename2020-03-28T14-45-08.237134.json
--->2-filename2020-03-28T14-45-09.148903.json
--->3-filename2020-03-28T14-45-10.046092.json
Where the first and second files contain exactly 100 items. The last one contains
100 items or fewer.
.. setting:: FEED_URI_PARAMS
FEED_URI_PARAMS
---------------
Default: ``None``
A string with the import path of a function to set the parameters to apply with
:ref:`printf-style string formatting <python:old-string-formatting>` to the
feed URI.
The function signature should be as follows:
.. function:: uri_params(params, spider)
Return a :class:`dict` of key-value pairs to apply to the feed URI using
:ref:`printf-style string formatting <python:old-string-formatting>`.
:param params: default key-value pairs
Specifically:
- ``batch_id``: ID of the file batch. See
:setting:`FEED_EXPORT_BATCH_ITEM_COUNT`.
If :setting:`FEED_EXPORT_BATCH_ITEM_COUNT` is ``0``, ``batch_id``
is always ``1``.
.. versionadded:: 2.3.0
- ``batch_time``: UTC date and time, in ISO format with ``:``
replaced with ``-``.
See :setting:`FEED_EXPORT_BATCH_ITEM_COUNT`.
.. versionadded:: 2.3.0
- ``time``: ``batch_time``, with microseconds set to ``0``.
:type params: dict
:param spider: source spider of the feed items
:type spider: scrapy.spiders.Spider
For example, to include the :attr:`name <scrapy.spiders.Spider.name>` of the
source spider in the feed URI:
#. Define the following function somewhere in your project::
# myproject/utils.py
def uri_params(params, spider):
return {**params, 'spider_name': spider.name}
#. Point :setting:`FEED_URI_PARAMS` to that function in your settings::
# myproject/settings.py
FEED_URI_PARAMS = 'myproject.utils.uri_params'
#. Use ``%(spider_name)s`` in your feed URI::
scrapy crawl <spider_name> -o "%(spider_name)s.jl"
.. _URIs: https://en.wikipedia.org/wiki/Uniform_Resource_Identifier
.. _Amazon S3: https://aws.amazon.com/s3/
.. _botocore: https://github.com/boto/botocore
.. _Canned ACL: https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl
.. _Google Cloud Storage: https://cloud.google.com/storage/

70
docs/topics/item-pipeline.rst
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@ -27,15 +27,19 @@ Each item pipeline component is a Python class that must implement the following
.. method:: process_item(self, item, spider)
This method is called for every item pipeline component. :meth:`process_item`
must either: return a dict with data, return an :class:`~scrapy.item.Item`
(or any descendant class) object, return a
:class:`~twisted.internet.defer.Deferred` or raise
:exc:`~scrapy.exceptions.DropItem` exception. Dropped items are no longer
processed by further pipeline components.
This method is called for every item pipeline component.
:param item: the item scraped
:type item: :class:`~scrapy.item.Item` object or a dict
`item` is an :ref:`item object <item-types>`, see
:ref:`supporting-item-types`.
:meth:`process_item` must either: return an :ref:`item object <item-types>`,
return a :class:`~twisted.internet.defer.Deferred` or raise a
:exc:`~scrapy.exceptions.DropItem` exception.
Dropped items are no longer processed by further pipeline components.
:param item: the scraped item
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -79,19 +83,20 @@ Let's take a look at the following hypothetical pipeline that adjusts the
(``price_excludes_vat`` attribute), and drops those items which don't
contain a price::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
class PricePipeline:
vat_factor = 1.15
def process_item(self, item, spider):
if item.get('price'):
if item.get('price_excludes_vat'):
item['price'] = item['price'] * self.vat_factor
adapter = ItemAdapter(item)
if adapter.get('price'):
if adapter.get('price_excludes_vat'):
adapter['price'] = adapter['price'] * self.vat_factor
return item
else:
raise DropItem("Missing price in %s" % item)
raise DropItem(f"Missing price in {item}")
Write items to a JSON file
@ -103,6 +108,8 @@ format::
import json
from itemadapter import ItemAdapter
class JsonWriterPipeline:
def open_spider(self, spider):
@ -112,7 +119,7 @@ format::
self.file.close()
def process_item(self, item, spider):
line = json.dumps(dict(item)) + "\n"
line = json.dumps(ItemAdapter(item).asdict()) + "\n"
self.file.write(line)
return item
@ -131,6 +138,7 @@ The main point of this example is to show how to use :meth:`from_crawler`
method and how to clean up the resources properly.::
import pymongo
from itemadapter import ItemAdapter
class MongoPipeline:
@ -155,7 +163,7 @@ method and how to clean up the resources properly.::
self.client.close()
def process_item(self, item, spider):
self.db[self.collection_name].insert_one(dict(item))
self.db[self.collection_name].insert_one(ItemAdapter(item).asdict())
return item
.. _MongoDB: https://www.mongodb.com/
@ -167,18 +175,21 @@ method and how to clean up the resources properly.::
Take screenshot of item
-----------------------
This example demonstrates how to return a
:class:`~twisted.internet.defer.Deferred` from the :meth:`process_item` method.
It uses Splash_ to render screenshot of item url. Pipeline
makes request to locally running instance of Splash_. After request is downloaded,
it saves the screenshot to a file and adds filename to the item.
This example demonstrates how to use :doc:`coroutine syntax <coroutines>` in
the :meth:`process_item` method.
This item pipeline makes a request to a locally-running instance of Splash_ to
render a screenshot of the item URL. After the request response is downloaded,
the item pipeline saves the screenshot to a file and adds the filename to the
item.
::
import scrapy
import hashlib
from urllib.parse import quote
import scrapy
from itemadapter import ItemAdapter
class ScreenshotPipeline:
"""Pipeline that uses Splash to render screenshot of
@ -187,7 +198,8 @@ it saves the screenshot to a file and adds filename to the item.
SPLASH_URL = "http://localhost:8050/render.png?url={}"
async def process_item(self, item, spider):
encoded_item_url = quote(item["url"])
adapter = ItemAdapter(item)
encoded_item_url = quote(adapter["url"])
screenshot_url = self.SPLASH_URL.format(encoded_item_url)
request = scrapy.Request(screenshot_url)
response = await spider.crawler.engine.download(request, spider)
@ -197,14 +209,14 @@ it saves the screenshot to a file and adds filename to the item.
return item
# Save screenshot to file, filename will be hash of url.
url = item["url"]
url = adapter["url"]
url_hash = hashlib.md5(url.encode("utf8")).hexdigest()
filename = "{}.png".format(url_hash)
filename = f"{url_hash}.png"
with open(filename, "wb") as f:
f.write(response.body)
# Store filename in item.
item["screenshot_filename"] = filename
adapter["screenshot_filename"] = filename
return item
.. _Splash: https://splash.readthedocs.io/en/stable/
@ -217,6 +229,7 @@ already processed. Let's say that our items have a unique id, but our spider
returns multiples items with the same id::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
class DuplicatesPipeline:
@ -225,10 +238,11 @@ returns multiples items with the same id::
self.ids_seen = set()
def process_item(self, item, spider):
if item['id'] in self.ids_seen:
raise DropItem("Duplicate item found: %s" % item)
adapter = ItemAdapter(item)
if adapter['id'] in self.ids_seen:
raise DropItem(f"Duplicate item found: {item!r}")
else:
self.ids_seen.add(item['id'])
self.ids_seen.add(adapter['id'])
return item

264
docs/topics/items.rst
View File

@ -8,31 +8,155 @@ Items
:synopsis: Item and Field classes
The main goal in scraping is to extract structured data from unstructured
sources, typically, web pages. Scrapy spiders can return the extracted data
as Python dicts. While convenient and familiar, Python dicts lack structure:
it is easy to make a typo in a field name or return inconsistent data,
especially in a larger project with many spiders.
sources, typically, web pages. :ref:`Spiders <topics-spiders>` may return the
extracted data as `items`, Python objects that define key-value pairs.
To define common output data format Scrapy provides the :class:`Item` class.
:class:`Item` objects are simple containers used to collect the scraped data.
They provide a `dictionary-like`_ API with a convenient syntax for declaring
their available fields.
Scrapy supports :ref:`multiple types of items <item-types>`. When you create an
item, you may use whichever type of item you want. When you write code that
receives an item, your code should :ref:`work for any item type
<supporting-item-types>`.
Various Scrapy components use extra information provided by Items:
exporters look at declared fields to figure out columns to export,
serialization can be customized using Item fields metadata, :mod:`trackref`
tracks Item instances to help find memory leaks
(see :ref:`topics-leaks-trackrefs`), etc.
.. _item-types:
.. _dictionary-like: https://docs.python.org/2/library/stdtypes.html#dict
Item Types
==========
Scrapy supports the following types of items, via the `itemadapter`_ library:
:ref:`dictionaries <dict-items>`, :ref:`Item objects <item-objects>`,
:ref:`dataclass objects <dataclass-items>`, and :ref:`attrs objects <attrs-items>`.
.. _itemadapter: https://github.com/scrapy/itemadapter
.. _dict-items:
Dictionaries
------------
As an item type, :class:`dict` is convenient and familiar.
.. _item-objects:
Item objects
------------
:class:`Item` provides a :class:`dict`-like API plus additional features that
make it the most feature-complete item type:
.. class:: Item([arg])
:class:`Item` objects replicate the standard :class:`dict` API, including
its ``__init__`` method.
:class:`Item` allows defining field names, so that:
- :class:`KeyError` is raised when using undefined field names (i.e.
prevents typos going unnoticed)
- :ref:`Item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all
of them
:class:`Item` also allows defining field metadata, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
:mod:`trackref` tracks :class:`Item` objects to help find memory leaks
(see :ref:`topics-leaks-trackrefs`).
:class:`Item` objects also provide the following additional API members:
.. automethod:: copy
.. automethod:: deepcopy
.. attribute:: fields
A dictionary containing *all declared fields* for this Item, not only
those populated. The keys are the field names and the values are the
:class:`Field` objects used in the :ref:`Item declaration
<topics-items-declaring>`.
Example::
from scrapy.item import Item, Field
class CustomItem(Item):
one_field = Field()
another_field = Field()
.. _dataclass-items:
Dataclass objects
-----------------
.. versionadded:: 2.2
:func:`~dataclasses.dataclass` allows defining item classes with field names,
so that :ref:`item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all of them.
Additionally, ``dataclass`` items also allow to:
* define the type and default value of each defined field.
* define custom field metadata through :func:`dataclasses.field`, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
They work natively in Python 3.7 or later, or using the `dataclasses
backport`_ in Python 3.6.
.. _dataclasses backport: https://pypi.org/project/dataclasses/
Example::
from dataclasses import dataclass
@dataclass
class CustomItem:
one_field: str
another_field: int
.. note:: Field types are not enforced at run time.
.. _attrs-items:
attr.s objects
--------------
.. versionadded:: 2.2
:func:`attr.s` allows defining item classes with field names,
so that :ref:`item exporters <topics-exporters>` can export all fields by
default even if the first scraped object does not have values for all of them.
Additionally, ``attr.s`` items also allow to:
* define the type and default value of each defined field.
* define custom field :ref:`metadata <attrs:metadata>`, which can be used to
:ref:`customize serialization <topics-exporters-field-serialization>`.
In order to use this type, the :doc:`attrs package <attrs:index>` needs to be installed.
Example::
import attr
@attr.s
class CustomItem:
one_field = attr.ib()
another_field = attr.ib()
Working with Item objects
=========================
.. _topics-items-declaring:
Declaring Items
===============
Declaring Item subclasses
-------------------------
Items are declared using a simple class definition syntax and :class:`Field`
objects. Here is an example::
Item subclasses are declared using a simple class definition syntax and
:class:`Field` objects. Here is an example::
import scrapy
@ -50,10 +174,11 @@ objects. Here is an example::
.. _Django: https://www.djangoproject.com/
.. _Django Models: https://docs.djangoproject.com/en/dev/topics/db/models/
.. _topics-items-fields:
Item Fields
===========
Declaring fields
----------------
:class:`Field` objects are used to specify metadata for each field. For
example, the serializer function for the ``last_updated`` field illustrated in
@ -74,15 +199,31 @@ It's important to note that the :class:`Field` objects used to declare the item
do not stay assigned as class attributes. Instead, they can be accessed through
the :attr:`Item.fields` attribute.
Working with Items
==================
.. class:: Field([arg])
The :class:`Field` class is just an alias to the built-in :class:`dict` class and
doesn't provide any extra functionality or attributes. In other words,
:class:`Field` objects are plain-old Python dicts. A separate class is used
to support the :ref:`item declaration syntax <topics-items-declaring>`
based on class attributes.
.. note:: Field metadata can also be declared for ``dataclass`` and ``attrs``
items. Please refer to the documentation for `dataclasses.field`_ and
`attr.ib`_ for additional information.
.. _dataclasses.field: https://docs.python.org/3/library/dataclasses.html#dataclasses.field
.. _attr.ib: https://www.attrs.org/en/stable/api.html#attr.ib
Working with Item objects
-------------------------
Here are some examples of common tasks performed with items, using the
``Product`` item :ref:`declared above <topics-items-declaring>`. You will
notice the API is very similar to the `dict API`_.
notice the API is very similar to the :class:`dict` API.
Creating items
--------------
''''''''''''''
>>> product = Product(name='Desktop PC', price=1000)
>>> print(product)
@ -90,7 +231,7 @@ Product(name='Desktop PC', price=1000)
Getting field values
--------------------
''''''''''''''''''''
>>> product['name']
Desktop PC
@ -130,7 +271,7 @@ False
Setting field values
--------------------
''''''''''''''''''''
>>> product['last_updated'] = 'today'
>>> product['last_updated']
@ -143,9 +284,9 @@ KeyError: 'Product does not support field: lala'
Accessing all populated values
------------------------------
''''''''''''''''''''''''''''''
To access all populated values, just use the typical `dict API`_:
To access all populated values, just use the typical :class:`dict` API:
>>> product.keys()
['price', 'name']
@ -157,16 +298,14 @@ To access all populated values, just use the typical `dict API`_:
.. _copying-items:
Copying items
-------------
'''''''''''''
To copy an item, you must first decide whether you want a shallow copy or a
deep copy.
If your item contains mutable_ values like lists or dictionaries, a shallow
copy will keep references to the same mutable values across all different
copies.
.. _mutable: https://docs.python.org/3/glossary.html#term-mutable
If your item contains :term:`mutable` values like lists or dictionaries,
a shallow copy will keep references to the same mutable values across all
different copies.
For example, if you have an item with a list of tags, and you create a shallow
copy of that item, both the original item and the copy have the same list of
@ -175,9 +314,7 @@ other item as well.
If that is not the desired behavior, use a deep copy instead.
See the `documentation of the copy module`_ for more information.
.. _documentation of the copy module: https://docs.python.org/3/library/copy.html
See :mod:`copy` for more information.
To create a shallow copy of an item, you can either call
:meth:`~scrapy.item.Item.copy` on an existing item
@ -189,7 +326,7 @@ To create a deep copy, call :meth:`~scrapy.item.Item.deepcopy` instead
Other common tasks
------------------
''''''''''''''''''
Creating dicts from items:
@ -207,8 +344,8 @@ Traceback (most recent call last):
KeyError: 'Product does not support field: lala'
Extending Items
===============
Extending Item subclasses
-------------------------
You can extend Items (to add more fields or to change some metadata for some
fields) by declaring a subclass of your original Item.
@ -228,46 +365,25 @@ appending more values, or changing existing values, like this::
That adds (or replaces) the ``serializer`` metadata key for the ``name`` field,
keeping all the previously existing metadata values.
Item objects
============
.. class:: Item([arg])
.. _supporting-item-types:
Return a new Item optionally initialized from the given argument.
Supporting All Item Types
=========================
Items replicate the standard `dict API`_, including its ``__init__`` method, and
also provide the following additional API members:
In code that receives an item, such as methods of :ref:`item pipelines
<topics-item-pipeline>` or :ref:`spider middlewares
<topics-spider-middleware>`, it is a good practice to use the
:class:`~itemadapter.ItemAdapter` class and the
:func:`~itemadapter.is_item` function to write code that works for
any :ref:`supported item type <item-types>`:
.. automethod:: copy
.. autoclass:: itemadapter.ItemAdapter
.. automethod:: deepcopy
.. attribute:: fields
A dictionary containing *all declared fields* for this Item, not only
those populated. The keys are the field names and the values are the
:class:`Field` objects used in the :ref:`Item declaration
<topics-items-declaring>`.
.. _dict API: https://docs.python.org/2/library/stdtypes.html#dict
Field objects
=============
.. class:: Field([arg])
The :class:`Field` class is just an alias to the built-in `dict`_ class and
doesn't provide any extra functionality or attributes. In other words,
:class:`Field` objects are plain-old Python dicts. A separate class is used
to support the :ref:`item declaration syntax <topics-items-declaring>`
based on class attributes.
.. _dict: https://docs.python.org/2/library/stdtypes.html#dict
.. autofunction:: itemadapter.is_item
Other classes related to Item
=============================
.. autoclass:: BaseItem
Other classes related to items
==============================
.. autoclass:: ItemMeta

2
docs/topics/jobs.rst
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@ -65,7 +65,7 @@ Cookies expiration
------------------
Cookies may expire. So, if you don't resume your spider quickly the requests
scheduled may no longer work. This won't be an issue if you spider doesn't rely
scheduled may no longer work. This won't be an issue if your spider doesn't rely
on cookies.

19
docs/topics/leaks.rst
View File

@ -4,7 +4,7 @@
Debugging memory leaks
======================
In Scrapy, objects such as Requests, Responses and Items have a finite
In Scrapy, objects such as requests, responses and items have a finite
lifetime: they are created, used for a while, and finally destroyed.
From all those objects, the Request is probably the one with the longest
@ -61,8 +61,8 @@ Debugging memory leaks with ``trackref``
========================================
:mod:`trackref` is a module provided by Scrapy to debug the most common cases of
memory leaks. It basically tracks the references to all live Requests,
Responses, Item and Selector objects.
memory leaks. It basically tracks the references to all live Request,
Response, Item, Spider and Selector objects.
You can enter the telnet console and inspect how many objects (of the classes
mentioned above) are currently alive using the ``prefs()`` function which is an
@ -102,7 +102,7 @@ A real example
Let's see a concrete example of a hypothetical case of memory leaks.
Suppose we have some spider with a line similar to this one::
return Request("http://www.somenastyspider.com/product.php?pid=%d" % product_id,
return Request(f"http://www.somenastyspider.com/product.php?pid={product_id}",
callback=self.parse, cb_kwargs={'referer': response})
That line is passing a response reference inside a request which effectively
@ -179,7 +179,7 @@ Here are the functions available in the :mod:`~scrapy.utils.trackref` module.
:param ignore: if given, all objects from the specified class (or tuple of
classes) will be ignored.
:type ignore: class or classes tuple
:type ignore: type or tuple
.. function:: get_oldest(class_name)
@ -200,11 +200,10 @@ Debugging memory leaks with muppy
``trackref`` provides a very convenient mechanism for tracking down memory
leaks, but it only keeps track of the objects that are more likely to cause
memory leaks (Requests, Responses, Items, and Selectors). However, there are
other cases where the memory leaks could come from other (more or less obscure)
objects. If this is your case, and you can't find your leaks using ``trackref``,
you still have another resource: the muppy library.
memory leaks. However, there are other cases where the memory leaks could come
from other (more or less obscure) objects. If this is your case, and you can't
find your leaks using ``trackref``, you still have another resource: the muppy
library.
You can use muppy from `Pympler`_.

35
docs/topics/link-extractors.rst
View File

@ -10,12 +10,19 @@ The ``__init__`` method of
:class:`~scrapy.linkextractors.lxmlhtml.LxmlLinkExtractor` takes settings that
determine which links may be extracted. :class:`LxmlLinkExtractor.extract_links
<scrapy.linkextractors.lxmlhtml.LxmlLinkExtractor.extract_links>` returns a
list of matching :class:`scrapy.link.Link` objects from a
list of matching :class:`~scrapy.link.Link` objects from a
:class:`~scrapy.http.Response` object.
Link extractors are used in :class:`~scrapy.spiders.CrawlSpider` spiders
through a set of :class:`~scrapy.spiders.Rule` objects. You can also use link
extractors in regular spiders.
through a set of :class:`~scrapy.spiders.Rule` objects.
You can also use link extractors in regular spiders. For example, you can instantiate
:class:`LinkExtractor <scrapy.linkextractors.lxmlhtml.LxmlLinkExtractor>` into a class
variable in your spider, and use it from your spider callbacks::
def parse(self, response):
for link in self.link_extractor.extract_links(response):
yield Request(link.url, callback=self.parse)
.. _topics-link-extractors-ref:
@ -46,13 +53,13 @@ LxmlLinkExtractor
:param allow: a single regular expression (or list of regular expressions)
that the (absolute) urls must match in order to be extracted. If not
given (or empty), it will match all links.
:type allow: a regular expression (or list of)
:type allow: str or list
:param deny: a single regular expression (or list of regular expressions)
that the (absolute) urls must match in order to be excluded (i.e. not
extracted). It has precedence over the ``allow`` parameter. If not
given (or empty) it won't exclude any links.
:type deny: a regular expression (or list of)
:type deny: str or list
:param allow_domains: a single value or a list of string containing
domains which will be considered for extracting the links
@ -88,7 +95,7 @@ LxmlLinkExtractor
that the link's text must match in order to be extracted. If not
given (or empty), it will match all links. If a list of regular expressions is
given, the link will be extracted if it matches at least one.
:type restrict_text: a regular expression (or list of)
:type restrict_text: str or list
:param tags: a tag or a list of tags to consider when extracting links.
Defaults to ``('a', 'area')``.
@ -106,11 +113,11 @@ LxmlLinkExtractor
different for requests with canonicalized and raw URLs. If you're
using LinkExtractor to follow links it is more robust to
keep the default ``canonicalize=False``.
:type canonicalize: boolean
:type canonicalize: bool
:param unique: whether duplicate filtering should be applied to extracted
links.
:type unique: boolean
:type unique: bool
:param process_value: a function which receives each value extracted from
the tag and attributes scanned and can modify the value and return a
@ -132,7 +139,7 @@ LxmlLinkExtractor
if m:
return m.group(1)
:type process_value: callable
:type process_value: collections.abc.Callable
:param strip: whether to strip whitespaces from extracted attributes.
According to HTML5 standard, leading and trailing whitespaces
@ -141,8 +148,16 @@ LxmlLinkExtractor
elements, etc., so LinkExtractor strips space chars by default.
Set ``strip=False`` to turn it off (e.g. if you're extracting urls
from elements or attributes which allow leading/trailing whitespaces).
:type strip: boolean
:type strip: bool
.. automethod:: extract_links
Link
----
.. module:: scrapy.link
:synopsis: Link from link extractors
.. autoclass:: Link
.. _scrapy.linkextractors: https://github.com/scrapy/scrapy/blob/master/scrapy/linkextractors/__init__.py

476
docs/topics/loaders.rst
View File

@ -7,13 +7,12 @@ Item Loaders
.. module:: scrapy.loader
:synopsis: Item Loader class
Item Loaders provide a convenient mechanism for populating scraped :ref:`Items
<topics-items>`. Even though Items can be populated using their own
dictionary-like API, Item Loaders provide a much more convenient API for
populating them from a scraping process, by automating some common tasks like
parsing the raw extracted data before assigning it.
Item Loaders provide a convenient mechanism for populating scraped :ref:`items
<topics-items>`. Even though items can be populated directly, Item Loaders provide a
much more convenient API for populating them from a scraping process, by automating
some common tasks like parsing the raw extracted data before assigning it.
In other words, :ref:`Items <topics-items>` provide the *container* of
In other words, :ref:`items <topics-items>` provide the *container* of
scraped data, while Item Loaders provide the mechanism for *populating* that
container.
@ -21,14 +20,18 @@ Item Loaders are designed to provide a flexible, efficient and easy mechanism
for extending and overriding different field parsing rules, either by spider,
or by source format (HTML, XML, etc) without becoming a nightmare to maintain.
.. note:: Item Loaders are an extension of the itemloaders_ library that make it
easier to work with Scrapy by adding support for
:ref:`responses <topics-request-response>`.
Using Item Loaders to populate items
====================================
To use an Item Loader, you must first instantiate it. You can either
instantiate it with a dict-like object (e.g. Item or dict) or without one, in
which case an Item is automatically instantiated in the Item Loader ``__init__`` method
using the Item class specified in the :attr:`ItemLoader.default_item_class`
attribute.
instantiate it with an :ref:`item object <topics-items>` or without one, in which
case an :ref:`item object <topics-items>` is automatically created in the
Item Loader ``__init__`` method using the :ref:`item <topics-items>` class
specified in the :attr:`ItemLoader.default_item_class` attribute.
Then, you start collecting values into the Item Loader, typically using
:ref:`Selectors <topics-selectors>`. You can add more than one value to
@ -77,6 +80,31 @@ called which actually returns the item populated with the data
previously extracted and collected with the :meth:`~ItemLoader.add_xpath`,
:meth:`~ItemLoader.add_css`, and :meth:`~ItemLoader.add_value` calls.
.. _topics-loaders-dataclass:
Working with dataclass items
============================
By default, :ref:`dataclass items <dataclass-items>` require all fields to be
passed when created. This could be an issue when using dataclass items with
item loaders: unless a pre-populated item is passed to the loader, fields
will be populated incrementally using the loader's :meth:`~ItemLoader.add_xpath`,
:meth:`~ItemLoader.add_css` and :meth:`~ItemLoader.add_value` methods.
One approach to overcome this is to define items using the
:func:`~dataclasses.field` function, with a ``default`` argument::
from dataclasses import dataclass, field
from typing import Optional
@dataclass
class InventoryItem:
name: Optional[str] = field(default=None)
price: Optional[float] = field(default=None)
stock: Optional[int] = field(default=None)
.. _topics-loaders-processors:
Input and Output processors
@ -88,7 +116,7 @@ received (through the :meth:`~ItemLoader.add_xpath`, :meth:`~ItemLoader.add_css`
:meth:`~ItemLoader.add_value` methods) and the result of the input processor is
collected and kept inside the ItemLoader. After collecting all data, the
:meth:`ItemLoader.load_item` method is called to populate and get the populated
:class:`~scrapy.item.Item` object. That's when the output processor is
:ref:`item object <topics-items>`. That's when the output processor is
called with the data previously collected (and processed using the input
processor). The result of the output processor is the final value that gets
assigned to the item.
@ -149,28 +177,26 @@ The other thing you need to keep in mind is that the values returned by input
processors are collected internally (in lists) and then passed to output
processors to populate the fields.
Last, but not least, Scrapy comes with some :ref:`commonly used processors
<topics-loaders-available-processors>` built-in for convenience.
Last, but not least, itemloaders_ comes with some :ref:`commonly used
processors <itemloaders:built-in-processors>` built-in for convenience.
Declaring Item Loaders
======================
Item Loaders are declared like Items, by using a class definition syntax. Here
is an example::
Item Loaders are declared using a class definition syntax. Here is an example::
from itemloaders.processors import TakeFirst, MapCompose, Join
from scrapy.loader import ItemLoader
from scrapy.loader.processors import TakeFirst, MapCompose, Join
class ProductLoader(ItemLoader):
default_output_processor = TakeFirst()
name_in = MapCompose(unicode.title)
name_in = MapCompose(str.title)
name_out = Join()
price_in = MapCompose(unicode.strip)
price_in = MapCompose(str.strip)
# ...
@ -192,7 +218,7 @@ output processors to use: in the :ref:`Item Field <topics-items-fields>`
metadata. Here is an example::
import scrapy
from scrapy.loader.processors import Join, MapCompose, TakeFirst
from itemloaders.processors import Join, MapCompose, TakeFirst
from w3lib.html import remove_tags
def filter_price(value):
@ -211,10 +237,10 @@ metadata. Here is an example::
>>> from scrapy.loader import ItemLoader
>>> il = ItemLoader(item=Product())
>>> il.add_value('name', [u'Welcome to my', u'<strong>website</strong>'])
>>> il.add_value('price', [u'&euro;', u'<span>1000</span>'])
>>> il.add_value('name', ['Welcome to my', '<strong>website</strong>'])
>>> il.add_value('price', ['&euro;', '<span>1000</span>'])
>>> il.load_item()
{'name': u'Welcome to my website', 'price': u'1000'}
{'name': 'Welcome to my website', 'price': '1000'}
The precedence order, for both input and output processors, is as follows:
@ -273,248 +299,9 @@ There are several ways to modify Item Loader context values:
ItemLoader objects
==================
.. class:: ItemLoader([item, selector, response], \**kwargs)
Return a new Item Loader for populating the given Item. If no item is
given, one is instantiated automatically using the class in
:attr:`default_item_class`.
When instantiated with a ``selector`` or a ``response`` parameters
the :class:`ItemLoader` class provides convenient mechanisms for extracting
data from web pages using :ref:`selectors <topics-selectors>`.
:param item: The item instance to populate using subsequent calls to
:meth:`~ItemLoader.add_xpath`, :meth:`~ItemLoader.add_css`,
or :meth:`~ItemLoader.add_value`.
:type item: :class:`~scrapy.item.Item` object
:param selector: The selector to extract data from, when using the
:meth:`add_xpath` (resp. :meth:`add_css`) or :meth:`replace_xpath`
(resp. :meth:`replace_css`) method.
:type selector: :class:`~scrapy.selector.Selector` object
:param response: The response used to construct the selector using the
:attr:`default_selector_class`, unless the selector argument is given,
in which case this argument is ignored.
:type response: :class:`~scrapy.http.Response` object
The item, selector, response and the remaining keyword arguments are
assigned to the Loader context (accessible through the :attr:`context` attribute).
:class:`ItemLoader` instances have the following methods:
.. method:: get_value(value, \*processors, \**kwargs)
Process the given ``value`` by the given ``processors`` and keyword
arguments.
Available keyword arguments:
:param re: a regular expression to use for extracting data from the
given value using :meth:`~scrapy.utils.misc.extract_regex` method,
applied before processors
:type re: str or compiled regex
Examples:
>>> from scrapy.loader.processors import TakeFirst
>>> loader.get_value(u'name: foo', TakeFirst(), unicode.upper, re='name: (.+)')
'FOO`
.. method:: add_value(field_name, value, \*processors, \**kwargs)
Process and then add the given ``value`` for the given field.
The value is first passed through :meth:`get_value` by giving the
``processors`` and ``kwargs``, and then passed through the
:ref:`field input processor <topics-loaders-processors>` and its result
appended to the data collected for that field. If the field already
contains collected data, the new data is added.
The given ``field_name`` can be ``None``, in which case values for
multiple fields may be added. And the processed value should be a dict
with field_name mapped to values.
Examples::
loader.add_value('name', u'Color TV')
loader.add_value('colours', [u'white', u'blue'])
loader.add_value('length', u'100')
loader.add_value('name', u'name: foo', TakeFirst(), re='name: (.+)')
loader.add_value(None, {'name': u'foo', 'sex': u'male'})
.. method:: replace_value(field_name, value, \*processors, \**kwargs)
Similar to :meth:`add_value` but replaces the collected data with the
new value instead of adding it.
.. method:: get_xpath(xpath, \*processors, \**kwargs)
Similar to :meth:`ItemLoader.get_value` but receives an XPath instead of a
value, which is used to extract a list of unicode strings from the
selector associated with this :class:`ItemLoader`.
:param xpath: the XPath to extract data from
:type xpath: str
:param re: a regular expression to use for extracting data from the
selected XPath region
:type re: str or compiled regex
Examples::
# HTML snippet: <p class="product-name">Color TV</p>
loader.get_xpath('//p[@class="product-name"]')
# HTML snippet: <p id="price">the price is $1200</p>
loader.get_xpath('//p[@id="price"]', TakeFirst(), re='the price is (.*)')
.. method:: add_xpath(field_name, xpath, \*processors, \**kwargs)
Similar to :meth:`ItemLoader.add_value` but receives an XPath instead of a
value, which is used to extract a list of unicode strings from the
selector associated with this :class:`ItemLoader`.
See :meth:`get_xpath` for ``kwargs``.
:param xpath: the XPath to extract data from
:type xpath: str
Examples::
# HTML snippet: <p class="product-name">Color TV</p>
loader.add_xpath('name', '//p[@class="product-name"]')
# HTML snippet: <p id="price">the price is $1200</p>
loader.add_xpath('price', '//p[@id="price"]', re='the price is (.*)')
.. method:: replace_xpath(field_name, xpath, \*processors, \**kwargs)
Similar to :meth:`add_xpath` but replaces collected data instead of
adding it.
.. method:: get_css(css, \*processors, \**kwargs)
Similar to :meth:`ItemLoader.get_value` but receives a CSS selector
instead of a value, which is used to extract a list of unicode strings
from the selector associated with this :class:`ItemLoader`.
:param css: the CSS selector to extract data from
:type css: str
:param re: a regular expression to use for extracting data from the
selected CSS region
:type re: str or compiled regex
Examples::
# HTML snippet: <p class="product-name">Color TV</p>
loader.get_css('p.product-name')
# HTML snippet: <p id="price">the price is $1200</p>
loader.get_css('p#price', TakeFirst(), re='the price is (.*)')
.. method:: add_css(field_name, css, \*processors, \**kwargs)
Similar to :meth:`ItemLoader.add_value` but receives a CSS selector
instead of a value, which is used to extract a list of unicode strings
from the selector associated with this :class:`ItemLoader`.
See :meth:`get_css` for ``kwargs``.
:param css: the CSS selector to extract data from
:type css: str
Examples::
# HTML snippet: <p class="product-name">Color TV</p>
loader.add_css('name', 'p.product-name')
# HTML snippet: <p id="price">the price is $1200</p>
loader.add_css('price', 'p#price', re='the price is (.*)')
.. method:: replace_css(field_name, css, \*processors, \**kwargs)
Similar to :meth:`add_css` but replaces collected data instead of
adding it.
.. method:: load_item()
Populate the item with the data collected so far, and return it. The
data collected is first passed through the :ref:`output processors
<topics-loaders-processors>` to get the final value to assign to each
item field.
.. method:: nested_xpath(xpath)
Create a nested loader with an xpath selector.
The supplied selector is applied relative to selector associated
with this :class:`ItemLoader`. The nested loader shares the :class:`Item`
with the parent :class:`ItemLoader` so calls to :meth:`add_xpath`,
:meth:`add_value`, :meth:`replace_value`, etc. will behave as expected.
.. method:: nested_css(css)
Create a nested loader with a css selector.
The supplied selector is applied relative to selector associated
with this :class:`ItemLoader`. The nested loader shares the :class:`Item`
with the parent :class:`ItemLoader` so calls to :meth:`add_xpath`,
:meth:`add_value`, :meth:`replace_value`, etc. will behave as expected.
.. method:: get_collected_values(field_name)
Return the collected values for the given field.
.. method:: get_output_value(field_name)
Return the collected values parsed using the output processor, for the
given field. This method doesn't populate or modify the item at all.
.. method:: get_input_processor(field_name)
Return the input processor for the given field.
.. method:: get_output_processor(field_name)
Return the output processor for the given field.
:class:`ItemLoader` instances have the following attributes:
.. attribute:: item
The :class:`~scrapy.item.Item` object being parsed by this Item Loader.
This is mostly used as a property so when attempting to override this
value, you may want to check out :attr:`default_item_class` first.
.. attribute:: context
The currently active :ref:`Context <topics-loaders-context>` of this
Item Loader.
.. attribute:: default_item_class
An Item class (or factory), used to instantiate items when not given in
the ``__init__`` method.
.. attribute:: default_input_processor
The default input processor to use for those fields which don't specify
one.
.. attribute:: default_output_processor
The default output processor to use for those fields which don't specify
one.
.. attribute:: default_selector_class
The class used to construct the :attr:`selector` of this
:class:`ItemLoader`, if only a response is given in the ``__init__`` method.
If a selector is given in the ``__init__`` method this attribute is ignored.
This attribute is sometimes overridden in subclasses.
.. attribute:: selector
The :class:`~scrapy.selector.Selector` object to extract data from.
It's either the selector given in the ``__init__`` method or one created from
the response given in the ``__init__`` method using the
:attr:`default_selector_class`. This attribute is meant to be
read-only.
.. autoclass:: scrapy.loader.ItemLoader
:members:
:inherited-members:
.. _topics-loaders-nested:
@ -585,7 +372,7 @@ those dashes in the final product names.
Here's how you can remove those dashes by reusing and extending the default
Product Item Loader (``ProductLoader``)::
from scrapy.loader.processors import MapCompose
from itemloaders.processors import MapCompose
from myproject.ItemLoaders import ProductLoader
def strip_dashes(x):
@ -598,7 +385,7 @@ Another case where extending Item Loaders can be very helpful is when you have
multiple source formats, for example XML and HTML. In the XML version you may
want to remove ``CDATA`` occurrences. Here's an example of how to do it::
from scrapy.loader.processors import MapCompose
from itemloaders.processors import MapCompose
from myproject.ItemLoaders import ProductLoader
from myproject.utils.xml import remove_cdata
@ -618,156 +405,5 @@ projects. Scrapy only provides the mechanism; it doesn't impose any specific
organization of your Loaders collection - that's up to you and your project's
needs.
.. _topics-loaders-available-processors:
Available built-in processors
=============================
.. module:: scrapy.loader.processors
:synopsis: A collection of processors to use with Item Loaders
Even though you can use any callable function as input and output processors,
Scrapy provides some commonly used processors, which are described below. Some
of them, like the :class:`MapCompose` (which is typically used as input
processor) compose the output of several functions executed in order, to
produce the final parsed value.
Here is a list of all built-in processors:
.. class:: Identity
The simplest processor, which doesn't do anything. It returns the original
values unchanged. It doesn't receive any ``__init__`` method arguments, nor does it
accept Loader contexts.
Example:
>>> from scrapy.loader.processors import Identity
>>> proc = Identity()
>>> proc(['one', 'two', 'three'])
['one', 'two', 'three']
.. class:: TakeFirst
Returns the first non-null/non-empty value from the values received,
so it's typically used as an output processor to single-valued fields.
It doesn't receive any ``__init__`` method arguments, nor does it accept Loader contexts.
Example:
>>> from scrapy.loader.processors import TakeFirst
>>> proc = TakeFirst()
>>> proc(['', 'one', 'two', 'three'])
'one'
.. class:: Join(separator=u' ')
Returns the values joined with the separator given in the ``__init__`` method, which
defaults to ``u' '``. It doesn't accept Loader contexts.
When using the default separator, this processor is equivalent to the
function: ``u' '.join``
Examples:
>>> from scrapy.loader.processors import Join
>>> proc = Join()
>>> proc(['one', 'two', 'three'])
'one two three'
>>> proc = Join('<br>')
>>> proc(['one', 'two', 'three'])
'one<br>two<br>three'
.. class:: Compose(\*functions, \**default_loader_context)
A processor which is constructed from the composition of the given
functions. This means that each input value of this processor is passed to
the first function, and the result of that function is passed to the second
function, and so on, until the last function returns the output value of
this processor.
By default, stop process on ``None`` value. This behaviour can be changed by
passing keyword argument ``stop_on_none=False``.
Example:
>>> from scrapy.loader.processors import Compose
>>> proc = Compose(lambda v: v[0], str.upper)
>>> proc(['hello', 'world'])
'HELLO'
Each function can optionally receive a ``loader_context`` parameter. For
those which do, this processor will pass the currently active :ref:`Loader
context <topics-loaders-context>` through that parameter.
The keyword arguments passed in the ``__init__`` method are used as the default
Loader context values passed to each function call. However, the final
Loader context values passed to functions are overridden with the currently
active Loader context accessible through the :meth:`ItemLoader.context`
attribute.
.. class:: MapCompose(\*functions, \**default_loader_context)
A processor which is constructed from the composition of the given
functions, similar to the :class:`Compose` processor. The difference with
this processor is the way internal results are passed among functions,
which is as follows:
The input value of this processor is *iterated* and the first function is
applied to each element. The results of these function calls (one for each element)
are concatenated to construct a new iterable, which is then used to apply the
second function, and so on, until the last function is applied to each
value of the list of values collected so far. The output values of the last
function are concatenated together to produce the output of this processor.
Each particular function can return a value or a list of values, which is
flattened with the list of values returned by the same function applied to
the other input values. The functions can also return ``None`` in which
case the output of that function is ignored for further processing over the
chain.
This processor provides a convenient way to compose functions that only
work with single values (instead of iterables). For this reason the
:class:`MapCompose` processor is typically used as input processor, since
data is often extracted using the
:meth:`~scrapy.selector.Selector.extract` method of :ref:`selectors
<topics-selectors>`, which returns a list of unicode strings.
The example below should clarify how it works:
>>> def filter_world(x):
... return None if x == 'world' else x
...
>>> from scrapy.loader.processors import MapCompose
>>> proc = MapCompose(filter_world, str.upper)
>>> proc(['hello', 'world', 'this', 'is', 'scrapy'])
['HELLO, 'THIS', 'IS', 'SCRAPY']
As with the Compose processor, functions can receive Loader contexts, and
``__init__`` method keyword arguments are used as default context values. See
:class:`Compose` processor for more info.
.. class:: SelectJmes(json_path)
Queries the value using the json path provided to the ``__init__`` method and returns the output.
Requires jmespath (https://github.com/jmespath/jmespath.py) to run.
This processor takes only one input at a time.
Example:
>>> from scrapy.loader.processors import SelectJmes, Compose, MapCompose
>>> proc = SelectJmes("foo") #for direct use on lists and dictionaries
>>> proc({'foo': 'bar'})
'bar'
>>> proc({'foo': {'bar': 'baz'}})
{'bar': 'baz'}
Working with Json:
>>> import json
>>> proc_single_json_str = Compose(json.loads, SelectJmes("foo"))
>>> proc_single_json_str('{"foo": "bar"}')
'bar'
>>> proc_json_list = Compose(json.loads, MapCompose(SelectJmes('foo')))
>>> proc_json_list('[{"foo":"bar"}, {"baz":"tar"}]')
['bar']
.. _itemloaders: https://itemloaders.readthedocs.io/en/latest/
.. _processors: https://itemloaders.readthedocs.io/en/latest/built-in-processors.html

76
docs/topics/logging.rst
View File

@ -9,8 +9,7 @@ Logging
explicit calls to the Python standard logging. Keep reading to learn more
about the new logging system.
Scrapy uses `Python's builtin logging system
<https://docs.python.org/3/library/logging.html>`_ for event logging. We'll
Scrapy uses :mod:`logging` for event logging. We'll
provide some simple examples to get you started, but for more advanced
use-cases it's strongly suggested to read thoroughly its documentation.
@ -83,10 +82,10 @@ path::
.. seealso::
Module logging, `HowTo <https://docs.python.org/2/howto/logging.html>`_
Module logging, :doc:`HowTo <howto/logging>`
Basic Logging Tutorial
Module logging, `Loggers <https://docs.python.org/2/library/logging.html#logger-objects>`_
Module logging, :ref:`Loggers <logger>`
Further documentation on loggers
.. _topics-logging-from-spiders:
@ -102,7 +101,7 @@ instance, which can be accessed and used like this::
class MySpider(scrapy.Spider):
name = 'myspider'
start_urls = ['https://scrapinghub.com']
start_urls = ['https://scrapy.org']
def parse(self, response):
self.logger.info('Parse function called on %s', response.url)
@ -118,7 +117,7 @@ Python logger you want. For example::
class MySpider(scrapy.Spider):
name = 'myspider'
start_urls = ['https://scrapinghub.com']
start_urls = ['https://scrapy.org']
def parse(self, response):
logger.info('Parse function called on %s', response.url)
@ -165,14 +164,12 @@ possible levels listed in :ref:`topics-logging-levels`.
:setting:`LOG_FORMAT` and :setting:`LOG_DATEFORMAT` specify formatting strings
used as layouts for all messages. Those strings can contain any placeholders
listed in `logging's logrecord attributes docs
<https://docs.python.org/2/library/logging.html#logrecord-attributes>`_ and
`datetime's strftime and strptime directives
<https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior>`_
listed in :ref:`logging's logrecord attributes docs <logrecord-attributes>` and
:ref:`datetime's strftime and strptime directives <strftime-strptime-behavior>`
respectively.
If :setting:`LOG_SHORT_NAMES` is set, then the logs will not display the Scrapy
component that prints the log. It is unset by default, hence logs contain the
component that prints the log. It is unset by default, hence logs contain the
Scrapy component responsible for that log output.
Command-line options
@ -190,7 +187,7 @@ to override some of the Scrapy settings regarding logging.
.. seealso::
Module `logging.handlers <https://docs.python.org/2/library/logging.handlers.html>`_
Module :mod:`logging.handlers`
Further documentation on available handlers
.. _custom-log-formats:
@ -201,10 +198,13 @@ Custom Log Formats
A custom log format can be set for different actions by extending
:class:`~scrapy.logformatter.LogFormatter` class and making
:setting:`LOG_FORMATTER` point to your new class.
.. autoclass:: scrapy.logformatter.LogFormatter
:members:
.. _topics-logging-advanced-customization:
Advanced customization
----------------------
@ -242,6 +242,47 @@ e.g. in the spider's ``__init__`` method::
If you run this spider again then INFO messages from
``scrapy.spidermiddlewares.httperror`` logger will be gone.
You can also filter log records by :class:`~logging.LogRecord` data. For
example, you can filter log records by message content using a substring or
a regular expression. Create a :class:`logging.Filter` subclass
and equip it with a regular expression pattern to
filter out unwanted messages::
import logging
import re
class ContentFilter(logging.Filter):
def filter(self, record):
match = re.search(r'\d{3} [Ee]rror, retrying', record.message)
if match:
return False
A project-level filter may be attached to the root
handler created by Scrapy, this is a wieldy way to
filter all loggers in different parts of the project
(middlewares, spider, etc.)::
import logging
import scrapy
class MySpider(scrapy.Spider):
# ...
def __init__(self, *args, **kwargs):
for handler in logging.root.handlers:
handler.addFilter(ContentFilter())
Alternatively, you may choose a specific logger
and hide it without affecting other loggers::
import logging
import scrapy
class MySpider(scrapy.Spider):
# ...
def __init__(self, *args, **kwargs):
logger = logging.getLogger('my_logger')
logger.addFilter(ContentFilter())
scrapy.utils.log module
=======================
@ -256,16 +297,15 @@ scrapy.utils.log module
In that case, its usage is not required but it's recommended.
Another option when running custom scripts is to manually configure the logging.
To do this you can use `logging.basicConfig()`_ to set a basic root handler.
To do this you can use :func:`logging.basicConfig` to set a basic root handler.
Note that :class:`~scrapy.crawler.CrawlerProcess` automatically calls ``configure_logging``,
so it is recommended to only use `logging.basicConfig()`_ together with
so it is recommended to only use :func:`logging.basicConfig` together with
:class:`~scrapy.crawler.CrawlerRunner`.
This is an example on how to redirect ``INFO`` or higher messages to a file::
import logging
from scrapy.utils.log import configure_logging
logging.basicConfig(
filename='log.txt',
@ -275,7 +315,3 @@ scrapy.utils.log module
Refer to :ref:`run-from-script` for more details about using Scrapy this
way.
.. _logging.basicConfig(): https://docs.python.org/2/library/logging.html#logging.basicConfig

111
docs/topics/media-pipeline.rst
View File

@ -15,7 +15,7 @@ typically you'll either use the Files Pipeline or the Images Pipeline.
Both pipelines implement these features:
* Avoid re-downloading media that was downloaded recently
* Specifying where to store the media (filesystem directory, Amazon S3 bucket,
* Specifying where to store the media (filesystem directory, FTP server, Amazon S3 bucket,
Google Cloud Storage bucket)
The Images Pipeline has a few extra functions for processing images:
@ -50,12 +50,14 @@ this:
4. When the files are downloaded, another field (``files``) will be populated
with the results. This field will contain a list of dicts with information
about the downloaded files, such as the downloaded path, the original
scraped url (taken from the ``file_urls`` field) , and the file checksum.
scraped url (taken from the ``file_urls`` field), the file checksum and the file status.
The files in the list of the ``files`` field will retain the same order of
the original ``file_urls`` field. If some file failed downloading, an
error will be logged and the file won't be present in the ``files`` field.
.. _images-pipeline:
Using the Images Pipeline
=========================
@ -68,14 +70,10 @@ The advantage of using the :class:`ImagesPipeline` for image files is that you
can configure some extra functions like generating thumbnails and filtering
the images based on their size.
The Images Pipeline uses `Pillow`_ for thumbnailing and normalizing images to
JPEG/RGB format, so you need to install this library in order to use it.
`Python Imaging Library`_ (PIL) should also work in most cases, but it is known
to cause troubles in some setups, so we recommend to use `Pillow`_ instead of
PIL.
The Images Pipeline requires Pillow_ 4.0.0 or greater. It is used for
thumbnailing and normalizing images to JPEG/RGB format.
.. _Pillow: https://github.com/python-pillow/Pillow
.. _Python Imaging Library: http://www.pythonware.com/products/pil/
.. _topics-media-pipeline-enabling:
@ -156,7 +154,7 @@ following forms::
ftp://username:password@address:port/path
ftp://address:port/path
If ``username`` and ``password`` are not provided, they are taken from the :setting:`FTP_USER` and
:setting:`FTP_PASSWORD` settings respectively.
@ -164,14 +162,17 @@ FTP supports two different connection modes: active or passive. Scrapy uses
the passive connection mode by default. To use the active connection mode instead,
set the :setting:`FEED_STORAGE_FTP_ACTIVE` setting to ``True``.
.. _media-pipelines-s3:
Amazon S3 storage
-----------------
.. setting:: FILES_STORE_S3_ACL
.. setting:: IMAGES_STORE_S3_ACL
:setting:`FILES_STORE` and :setting:`IMAGES_STORE` can represent an Amazon S3
bucket. Scrapy will automatically upload the files to the bucket.
If botocore_ >= 1.4.87 is installed, :setting:`FILES_STORE` and
:setting:`IMAGES_STORE` can represent an Amazon S3 bucket. Scrapy will
automatically upload the files to the bucket.
For example, this is a valid :setting:`IMAGES_STORE` value::
@ -187,8 +188,9 @@ policy::
For more information, see `canned ACLs`_ in the Amazon S3 Developer Guide.
Because Scrapy uses ``botocore`` internally you can also use other S3-like storages. Storages like
self-hosted `Minio`_ or `s3.scality`_. All you need to do is set endpoint option in you Scrapy settings::
You can also use other S3-like storages. Storages like self-hosted `Minio`_ or
`s3.scality`_. All you need to do is set endpoint option in you Scrapy
settings::
AWS_ENDPOINT_URL = 'http://minio.example.com:9000'
@ -197,14 +199,17 @@ For self-hosting you also might feel the need not to use SSL and not to verify S
AWS_USE_SSL = False # or True (None by default)
AWS_VERIFY = False # or True (None by default)
.. _botocore: https://github.com/boto/botocore
.. _canned ACLs: https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl
.. _Minio: https://github.com/minio/minio
.. _s3.scality: https://s3.scality.com/
.. _canned ACLs: https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl
.. _media-pipeline-gcs:
Google Cloud Storage
---------------------
.. setting:: GCS_PROJECT_ID
.. setting:: FILES_STORE_GCS_ACL
.. setting:: IMAGES_STORE_GCS_ACL
@ -243,20 +248,22 @@ Usage example
.. setting:: IMAGES_URLS_FIELD
.. setting:: IMAGES_RESULT_FIELD
In order to use a media pipeline first, :ref:`enable it
In order to use a media pipeline, first :ref:`enable it
<topics-media-pipeline-enabling>`.
Then, if a spider returns a dict with the URLs key (``file_urls`` or
``image_urls``, for the Files or Images Pipeline respectively), the pipeline will
put the results under respective key (``files`` or ``images``).
Then, if a spider returns an :ref:`item object <topics-items>` with the URLs
field (``file_urls`` or ``image_urls``, for the Files or Images Pipeline
respectively), the pipeline will put the results under the respective field
(``files`` or ``images``).
If you prefer to use :class:`~.Item`, then define a custom item with the
necessary fields, like in this example for Images Pipeline::
When using :ref:`item types <item-types>` for which fields are defined beforehand,
you must define both the URLs field and the results field. For example, when
using the images pipeline, items must define both the ``image_urls`` and the
``images`` field. For instance, using the :class:`~scrapy.item.Item` class::
import scrapy
class MyItem(scrapy.Item):
# ... other item fields ...
image_urls = scrapy.Field()
images = scrapy.Field()
@ -408,15 +415,16 @@ See here the methods that you can override in your custom Files Pipeline:
.. class:: FilesPipeline
.. method:: file_path(self, request, response=None, info=None)
.. method:: file_path(self, request, response=None, info=None, *, item=None)
This method is called once per downloaded item. It returns the
download path of the file originating from the specified
:class:`response <scrapy.http.Response>`.
In addition to ``response``, this method receives the original
:class:`request <scrapy.Request>` and
:class:`info <scrapy.pipelines.media.MediaPipeline.SpiderInfo>`.
:class:`request <scrapy.Request>`,
:class:`info <scrapy.pipelines.media.MediaPipeline.SpiderInfo>` and
:class:`item <scrapy.item.Item>`
You can override this method to customize the download path of each file.
@ -432,12 +440,18 @@ See here the methods that you can override in your custom Files Pipeline:
class MyFilesPipeline(FilesPipeline):
def file_path(self, request, response=None, info=None):
def file_path(self, request, response=None, info=None, *, item=None):
return 'files/' + os.path.basename(urlparse(request.url).path)
Similarly, you can use the ``item`` to determine the file path based on some item
property.
By default the :meth:`file_path` method returns
``full/<request URL hash>.<extension>``.
.. versionadded:: 2.4
The *item* parameter.
.. method:: FilesPipeline.get_media_requests(item, info)
As seen on the workflow, the pipeline will get the URLs of the images to
@ -445,8 +459,11 @@ See here the methods that you can override in your custom Files Pipeline:
:meth:`~get_media_requests` method and return a Request for each
file URL::
from itemadapter import ItemAdapter
def get_media_requests(self, item, info):
for file_url in item['file_urls']:
adapter = ItemAdapter(item)
for file_url in adapter['file_urls']:
yield scrapy.Request(file_url)
Those requests will be processed by the pipeline and, when they have finished
@ -470,6 +487,18 @@ See here the methods that you can override in your custom Files Pipeline:
* ``checksum`` - a `MD5 hash`_ of the image contents
* ``status`` - the file status indication.
.. versionadded:: 2.2
It can be one of the following:
* ``downloaded`` - file was downloaded.
* ``uptodate`` - file was not downloaded, as it was downloaded recently,
according to the file expiration policy.
* ``cached`` - file was already scheduled for download, by another item
sharing the same file.
The list of tuples received by :meth:`~item_completed` is
guaranteed to retain the same order of the requests returned from the
:meth:`~get_media_requests` method.
@ -479,7 +508,8 @@ See here the methods that you can override in your custom Files Pipeline:
[(True,
{'checksum': '2b00042f7481c7b056c4b410d28f33cf',
'path': 'full/0a79c461a4062ac383dc4fade7bc09f1384a3910.jpg',
'url': 'http://www.example.com/files/product1.pdf'}),
'url': 'http://www.example.com/files/product1.pdf',
'status': 'downloaded'}),
(False,
Failure(...))]
@ -500,13 +530,15 @@ See here the methods that you can override in your custom Files Pipeline:
store the downloaded file paths (passed in results) in the ``file_paths``
item field, and we drop the item if it doesn't contain any files::
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
def item_completed(self, results, item, info):
file_paths = [x['path'] for ok, x in results if ok]
if not file_paths:
raise DropItem("Item contains no files")
item['file_paths'] = file_paths
adapter = ItemAdapter(item)
adapter['file_paths'] = file_paths
return item
By default, the :meth:`item_completed` method returns the item.
@ -522,15 +554,16 @@ See here the methods that you can override in your custom Images Pipeline:
The :class:`ImagesPipeline` is an extension of the :class:`FilesPipeline`,
customizing the field names and adding custom behavior for images.
.. method:: file_path(self, request, response=None, info=None)
.. method:: file_path(self, request, response=None, info=None, *, item=None)
This method is called once per downloaded item. It returns the
download path of the file originating from the specified
:class:`response <scrapy.http.Response>`.
In addition to ``response``, this method receives the original
:class:`request <scrapy.Request>` and
:class:`info <scrapy.pipelines.media.MediaPipeline.SpiderInfo>`.
:class:`request <scrapy.Request>`,
:class:`info <scrapy.pipelines.media.MediaPipeline.SpiderInfo>` and
:class:`item <scrapy.item.Item>`
You can override this method to customize the download path of each file.
@ -546,12 +579,18 @@ See here the methods that you can override in your custom Images Pipeline:
class MyImagesPipeline(ImagesPipeline):
def file_path(self, request, response=None, info=None):
def file_path(self, request, response=None, info=None, *, item=None):
return 'files/' + os.path.basename(urlparse(request.url).path)
Similarly, you can use the ``item`` to determine the file path based on some item
property.
By default the :meth:`file_path` method returns
``full/<request URL hash>.<extension>``.
.. versionadded:: 2.4
The *item* parameter.
.. method:: ImagesPipeline.get_media_requests(item, info)
Works the same way as :meth:`FilesPipeline.get_media_requests` method,
@ -580,8 +619,9 @@ Here is a full example of the Images Pipeline whose methods are exemplified
above::
import scrapy
from scrapy.pipelines.images import ImagesPipeline
from itemadapter import ItemAdapter
from scrapy.exceptions import DropItem
from scrapy.pipelines.images import ImagesPipeline
class MyImagesPipeline(ImagesPipeline):
@ -593,7 +633,8 @@ above::
image_paths = [x['path'] for ok, x in results if ok]
if not image_paths:
raise DropItem("Item contains no images")
item['image_paths'] = image_paths
adapter = ItemAdapter(item)
adapter['image_paths'] = image_paths
return item

23
docs/topics/practices.rst
View File

@ -35,8 +35,9 @@ Here's an example showing how to run a single spider with it.
...
process = CrawlerProcess(settings={
'FEED_FORMAT': 'json',
'FEED_URI': 'items.json'
"FEEDS": {
"items.json": {"format": "json"},
},
})
process.crawl(MySpider)
@ -62,7 +63,7 @@ project as example.
process = CrawlerProcess(get_project_settings())
# 'followall' is the name of one of the spiders of the project.
process.crawl('followall', domain='scrapinghub.com')
process.crawl('followall', domain='scrapy.org')
process.start() # the script will block here until the crawling is finished
There's another Scrapy utility that provides more control over the crawling
@ -118,6 +119,7 @@ Here is an example that runs multiple spiders simultaneously:
import scrapy
from scrapy.crawler import CrawlerProcess
from scrapy.utils.project import get_project_settings
class MySpider1(scrapy.Spider):
# Your first spider definition
@ -127,7 +129,8 @@ Here is an example that runs multiple spiders simultaneously:
# Your second spider definition
...
process = CrawlerProcess()
settings = get_project_settings()
process = CrawlerProcess(settings)
process.crawl(MySpider1)
process.crawl(MySpider2)
process.start() # the script will block here until all crawling jobs are finished
@ -140,6 +143,7 @@ Same example using :class:`~scrapy.crawler.CrawlerRunner`:
from twisted.internet import reactor
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from scrapy.utils.project import get_project_settings
class MySpider1(scrapy.Spider):
# Your first spider definition
@ -150,7 +154,8 @@ Same example using :class:`~scrapy.crawler.CrawlerRunner`:
...
configure_logging()
runner = CrawlerRunner()
settings = get_project_settings()
runner = CrawlerRunner(settings)
runner.crawl(MySpider1)
runner.crawl(MySpider2)
d = runner.join()
@ -165,6 +170,7 @@ Same example but running the spiders sequentially by chaining the deferreds:
from twisted.internet import reactor, defer
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from scrapy.utils.project import get_project_settings
class MySpider1(scrapy.Spider):
# Your first spider definition
@ -175,7 +181,8 @@ Same example but running the spiders sequentially by chaining the deferreds:
...
configure_logging()
runner = CrawlerRunner()
settings = get_project_settings()
runner = CrawlerRunner(settings)
@defer.inlineCallbacks
def crawl():
@ -243,7 +250,7 @@ Here are some tips to keep in mind when dealing with these kinds of sites:
super proxy that you can attach your own proxies to.
* use a highly distributed downloader that circumvents bans internally, so you
can just focus on parsing clean pages. One example of such downloaders is
`Crawlera`_
`Zyte Smart Proxy Manager`_
If you are still unable to prevent your bot getting banned, consider contacting
`commercial support`_.
@ -253,5 +260,5 @@ If you are still unable to prevent your bot getting banned, consider contacting
.. _ProxyMesh: https://proxymesh.com/
.. _Google cache: http://www.googleguide.com/cached_pages.html
.. _testspiders: https://github.com/scrapinghub/testspiders
.. _Crawlera: https://scrapinghub.com/crawlera
.. _scrapoxy: https://scrapoxy.io/
.. _Zyte Smart Proxy Manager: https://www.zyte.com/smart-proxy-manager/

292
docs/topics/request-response.rst
View File

@ -26,41 +26,43 @@ Request objects
.. autoclass:: Request
A :class:`Request` object represents an HTTP request, which is usually
generated in the Spider and executed by the Downloader, and thus generating
a :class:`Response`.
:param url: the URL of this request
If the URL is invalid, a :exc:`ValueError` exception is raised.
:type url: string
:type url: str
:param callback: the function that will be called with the response of this
request (once its downloaded) as its first parameter. For more information
request (once it's downloaded) as its first parameter. For more information
see :ref:`topics-request-response-ref-request-callback-arguments` below.
If a Request doesn't specify a callback, the spider's
:meth:`~scrapy.spiders.Spider.parse` method will be used.
Note that if exceptions are raised during processing, errback is called instead.
:type callback: callable
:type callback: collections.abc.Callable
:param method: the HTTP method of this request. Defaults to ``'GET'``.
:type method: string
:type method: str
:param meta: the initial values for the :attr:`Request.meta` attribute. If
given, the dict passed in this parameter will be shallow copied.
:type meta: dict
:param body: the request body. If a ``unicode`` is passed, then it's encoded to
``str`` using the ``encoding`` passed (which defaults to ``utf-8``). If
``body`` is not given, an empty string is stored. Regardless of the
type of this argument, the final value stored will be a ``str`` (never
``unicode`` or ``None``).
:type body: str or unicode
:param body: the request body. If a string is passed, then it's encoded as
bytes using the ``encoding`` passed (which defaults to ``utf-8``). If
``body`` is not given, an empty bytes object is stored. Regardless of the
type of this argument, the final value stored will be a bytes object
(never a string or ``None``).
:type body: bytes or str
:param headers: the headers of this request. The dict values can be strings
(for single valued headers) or lists (for multi-valued headers). If
``None`` is passed as value, the HTTP header will not be sent at all.
.. caution:: Cookies set via the ``Cookie`` header are not considered by the
:ref:`cookies-mw`. If you need to set cookies for a request, use the
:class:`Request.cookies <scrapy.http.Request>` parameter. This is a known
current limitation that is being worked on.
:type headers: dict
:param cookies: the request cookies. These can be sent in two forms.
@ -102,12 +104,18 @@ Request objects
)
For more info see :ref:`cookies-mw`.
.. caution:: Cookies set via the ``Cookie`` header are not considered by the
:ref:`cookies-mw`. If you need to set cookies for a request, use the
:class:`Request.cookies <scrapy.http.Request>` parameter. This is a known
current limitation that is being worked on.
:type cookies: dict or list
:param encoding: the encoding of this request (defaults to ``'utf-8'``).
This encoding will be used to percent-encode the URL and to convert the
body to ``str`` (if given as ``unicode``).
:type encoding: string
body to bytes (if given as a string).
:type encoding: str
:param priority: the priority of this request (defaults to ``0``).
The priority is used by the scheduler to define the order used to process
@ -119,7 +127,7 @@ Request objects
the scheduler. This is used when you want to perform an identical
request multiple times, to ignore the duplicates filter. Use it with
care, or you will get into crawling loops. Default to ``False``.
:type dont_filter: boolean
:type dont_filter: bool
:param errback: a function that will be called if any exception was
raised while processing the request. This includes pages that failed
@ -131,7 +139,7 @@ Request objects
.. versionchanged:: 2.0
The *callback* parameter is no longer required when the *errback*
parameter is specified.
:type errback: callable
:type errback: collections.abc.Callable
:param flags: Flags sent to the request, can be used for logging or similar purposes.
:type flags: list
@ -159,7 +167,7 @@ Request objects
.. attribute:: Request.body
A str that contains the request body.
The request body as bytes.
This attribute is read-only. To change the body of a Request use
:meth:`replace`.
@ -174,9 +182,9 @@ Request objects
See :ref:`topics-request-meta` for a list of special meta keys
recognized by Scrapy.
This dict is `shallow copied`_ when the request is cloned using the
``copy()`` or ``replace()`` methods, and can also be accessed, in your
spider, from the ``response.meta`` attribute.
This dict is :doc:`shallow copied <library/copy>` when the request is
cloned using the ``copy()`` or ``replace()`` methods, and can also be
accessed, in your spider, from the ``response.meta`` attribute.
.. attribute:: Request.cb_kwargs
@ -185,11 +193,15 @@ Request objects
for new Requests, which means by default callbacks only get a :class:`Response`
object as argument.
This dict is `shallow copied`_ when the request is cloned using the
``copy()`` or ``replace()`` methods, and can also be accessed, in your
spider, from the ``response.cb_kwargs`` attribute.
This dict is :doc:`shallow copied <library/copy>` when the request is
cloned using the ``copy()`` or ``replace()`` methods, and can also be
accessed, in your spider, from the ``response.cb_kwargs`` attribute.
.. _shallow copied: https://docs.python.org/2/library/copy.html
In case of a failure to process the request, this dict can be accessed as
``failure.request.cb_kwargs`` in the request's errback. For more information,
see :ref:`errback-cb_kwargs`.
.. autoattribute:: Request.attributes
.. method:: Request.copy()
@ -206,6 +218,15 @@ Request objects
.. automethod:: from_curl
.. automethod:: to_dict
Other functions related to requests
-----------------------------------
.. autofunction:: scrapy.utils.request.request_from_dict
.. _topics-request-response-ref-request-callback-arguments:
Passing additional data to callback functions
@ -314,6 +335,31 @@ errors if needed::
request = failure.request
self.logger.error('TimeoutError on %s', request.url)
.. _errback-cb_kwargs:
Accessing additional data in errback functions
----------------------------------------------
In case of a failure to process the request, you may be interested in
accessing arguments to the callback functions so you can process further
based on the arguments in the errback. The following example shows how to
achieve this by using ``Failure.request.cb_kwargs``::
def parse(self, response):
request = scrapy.Request('http://www.example.com/index.html',
callback=self.parse_page2,
errback=self.errback_page2,
cb_kwargs=dict(main_url=response.url))
yield request
def parse_page2(self, response, main_url):
pass
def errback_page2(self, failure):
yield dict(
main_url=failure.request.cb_kwargs['main_url'],
)
.. _topics-request-meta:
Request.meta special keys
@ -324,26 +370,26 @@ are some special keys recognized by Scrapy and its built-in extensions.
Those are:
* :reqmeta:`dont_redirect`
* :reqmeta:`dont_retry`
* :reqmeta:`handle_httpstatus_list`
* :reqmeta:`handle_httpstatus_all`
* :reqmeta:`dont_merge_cookies`
* :reqmeta:`bindaddress`
* :reqmeta:`cookiejar`
* :reqmeta:`dont_cache`
* :reqmeta:`dont_merge_cookies`
* :reqmeta:`dont_obey_robotstxt`
* :reqmeta:`dont_redirect`
* :reqmeta:`dont_retry`
* :reqmeta:`download_fail_on_dataloss`
* :reqmeta:`download_latency`
* :reqmeta:`download_maxsize`
* :reqmeta:`download_timeout`
* ``ftp_password`` (See :setting:`FTP_PASSWORD` for more info)
* ``ftp_user`` (See :setting:`FTP_USER` for more info)
* :reqmeta:`handle_httpstatus_all`
* :reqmeta:`handle_httpstatus_list`
* :reqmeta:`max_retry_times`
* :reqmeta:`proxy`
* :reqmeta:`redirect_reasons`
* :reqmeta:`redirect_urls`
* :reqmeta:`bindaddress`
* :reqmeta:`dont_obey_robotstxt`
* :reqmeta:`download_timeout`
* :reqmeta:`download_maxsize`
* :reqmeta:`download_latency`
* :reqmeta:`download_fail_on_dataloss`
* :reqmeta:`proxy`
* ``ftp_user`` (See :setting:`FTP_USER` for more info)
* ``ftp_password`` (See :setting:`FTP_PASSWORD` for more info)
* :reqmeta:`referrer_policy`
* :reqmeta:`max_retry_times`
.. reqmeta:: bindaddress
@ -387,6 +433,51 @@ The meta key is used set retry times per request. When initialized, the
:reqmeta:`max_retry_times` meta key takes higher precedence over the
:setting:`RETRY_TIMES` setting.
.. _topics-stop-response-download:
Stopping the download of a Response
===================================
Raising a :exc:`~scrapy.exceptions.StopDownload` exception from a handler for the
:class:`~scrapy.signals.bytes_received` or :class:`~scrapy.signals.headers_received`
signals will stop the download of a given response. See the following example::
import scrapy
class StopSpider(scrapy.Spider):
name = "stop"
start_urls = ["https://docs.scrapy.org/en/latest/"]
@classmethod
def from_crawler(cls, crawler):
spider = super().from_crawler(crawler)
crawler.signals.connect(spider.on_bytes_received, signal=scrapy.signals.bytes_received)
return spider
def parse(self, response):
# 'last_chars' show that the full response was not downloaded
yield {"len": len(response.text), "last_chars": response.text[-40:]}
def on_bytes_received(self, data, request, spider):
raise scrapy.exceptions.StopDownload(fail=False)
which produces the following output::
2020-05-19 17:26:12 [scrapy.core.engine] INFO: Spider opened
2020-05-19 17:26:12 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2020-05-19 17:26:13 [scrapy.core.downloader.handlers.http11] DEBUG: Download stopped for <GET https://docs.scrapy.org/en/latest/> from signal handler StopSpider.on_bytes_received
2020-05-19 17:26:13 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://docs.scrapy.org/en/latest/> (referer: None) ['download_stopped']
2020-05-19 17:26:13 [scrapy.core.scraper] DEBUG: Scraped from <200 https://docs.scrapy.org/en/latest/>
{'len': 279, 'last_chars': 'dth, initial-scale=1.0">\n \n <title>Scr'}
2020-05-19 17:26:13 [scrapy.core.engine] INFO: Closing spider (finished)
By default, resulting responses are handled by their corresponding errbacks. To
call their callback instead, like in this example, pass ``fail=False`` to the
:exc:`~scrapy.exceptions.StopDownload` exception.
.. _topics-request-response-ref-request-subclasses:
Request subclasses
@ -413,7 +504,7 @@ fields with form data from :class:`Response` objects.
:param formdata: is a dictionary (or iterable of (key, value) tuples)
containing HTML Form data which will be url-encoded and assigned to the
body of the request.
:type formdata: dict or iterable of tuples
:type formdata: dict or collections.abc.Iterable
The :class:`FormRequest` objects support the following class method in
addition to the standard :class:`Request` methods:
@ -445,20 +536,20 @@ fields with form data from :class:`Response` objects.
:type response: :class:`Response` object
:param formname: if given, the form with name attribute set to this value will be used.
:type formname: string
:type formname: str
:param formid: if given, the form with id attribute set to this value will be used.
:type formid: string
:type formid: str
:param formxpath: if given, the first form that matches the xpath will be used.
:type formxpath: string
:type formxpath: str
:param formcss: if given, the first form that matches the css selector will be used.
:type formcss: string
:type formcss: str
:param formnumber: the number of form to use, when the response contains
multiple forms. The first one (and also the default) is ``0``.
:type formnumber: integer
:type formnumber: int
:param formdata: fields to override in the form data. If a field was
already present in the response ``<form>`` element, its value is
@ -476,23 +567,11 @@ fields with form data from :class:`Response` objects.
:param dont_click: If True, the form data will be submitted without
clicking in any element.
:type dont_click: boolean
:type dont_click: bool
The other parameters of this class method are passed directly to the
:class:`FormRequest` ``__init__`` method.
.. versionadded:: 0.10.3
The ``formname`` parameter.
.. versionadded:: 0.17
The ``formxpath`` parameter.
.. versionadded:: 1.1.0
The ``formcss`` parameter.
.. versionadded:: 1.1.0
The ``formid`` parameter.
Request usage examples
----------------------
@ -564,13 +643,13 @@ dealing with JSON requests.
if :attr:`Request.body` argument is provided this parameter will be ignored.
if :attr:`Request.body` argument is not provided and data argument is provided :attr:`Request.method` will be
set to ``'POST'`` automatically.
:type data: JSON serializable object
:type data: object
:param dumps_kwargs: Parameters that will be passed to underlying `json.dumps`_ method which is used to serialize
:param dumps_kwargs: Parameters that will be passed to underlying :func:`json.dumps` method which is used to serialize
data into JSON format.
:type dumps_kwargs: dict
.. _json.dumps: https://docs.python.org/3/library/json.html#json.dumps
.. autoattribute:: JsonRequest.attributes
JsonRequest usage example
-------------------------
@ -593,16 +672,16 @@ Response objects
downloaded (by the Downloader) and fed to the Spiders for processing.
:param url: the URL of this response
:type url: string
:type url: str
:param status: the HTTP status of the response. Defaults to ``200``.
:type status: integer
:type status: int
:param headers: the headers of this response. The dict values can be strings
(for single valued headers) or lists (for multi-valued headers).
:type headers: dict
:param body: the response body. To access the decoded text as str you can use
:param body: the response body. To access the decoded text as a string, use
``response.text`` from an encoding-aware
:ref:`Response subclass <topics-request-response-ref-response-subclasses>`,
such as :class:`TextResponse`.
@ -620,6 +699,22 @@ Response objects
:param certificate: an object representing the server's SSL certificate.
:type certificate: twisted.internet.ssl.Certificate
:param ip_address: The IP address of the server from which the Response originated.
:type ip_address: :class:`ipaddress.IPv4Address` or :class:`ipaddress.IPv6Address`
:param protocol: The protocol that was used to download the response.
For instance: "HTTP/1.0", "HTTP/1.1", "h2"
:type protocol: :class:`str`
.. versionadded:: 2.0.0
The ``certificate`` parameter.
.. versionadded:: 2.1.0
The ``ip_address`` parameter.
.. versionadded:: 2.5.0
The ``protocol`` parameter.
.. attribute:: Response.url
A string containing the URL of the response.
@ -644,10 +739,10 @@ Response objects
.. attribute:: Response.body
The body of this Response. Keep in mind that Response.body
is always a bytes object. If you want the unicode version use
:attr:`TextResponse.text` (only available in :class:`TextResponse`
and subclasses).
The response body as bytes.
If you want the body as a string, use :attr:`TextResponse.text` (only
available in :class:`TextResponse` and subclasses).
This attribute is read-only. To change the body of a Response use
:meth:`replace`.
@ -704,11 +799,34 @@ Response objects
.. attribute:: Response.certificate
.. versionadded:: 2.0.0
A :class:`twisted.internet.ssl.Certificate` object representing
the server's SSL certificate.
Only populated for ``https`` responses, ``None`` otherwise.
.. attribute:: Response.ip_address
.. versionadded:: 2.1.0
The IP address of the server from which the Response originated.
This attribute is currently only populated by the HTTP 1.1 download
handler, i.e. for ``http(s)`` responses. For other handlers,
:attr:`ip_address` is always ``None``.
.. attribute:: Response.protocol
.. versionadded:: 2.5.0
The protocol that was used to download the response.
For instance: "HTTP/1.0", "HTTP/1.1"
This attribute is currently only populated by the HTTP download
handlers, i.e. for ``http(s)`` responses. For other handlers,
:attr:`protocol` is always ``None``.
.. method:: Response.copy()
Returns a new Response which is a copy of this Response.
@ -724,18 +842,16 @@ Response objects
Constructs an absolute url by combining the Response's :attr:`url` with
a possible relative url.
This is a wrapper over `urlparse.urljoin`_, it's merely an alias for
This is a wrapper over :func:`~urllib.parse.urljoin`, it's merely an alias for
making this call::
urlparse.urljoin(response.url, url)
urllib.parse.urljoin(response.url, url)
.. automethod:: Response.follow
.. automethod:: Response.follow_all
.. _urlparse.urljoin: https://docs.python.org/2/library/urlparse.html#urlparse.urljoin
.. _topics-request-response-ref-response-subclasses:
Response subclasses
@ -758,18 +874,18 @@ TextResponse objects
is the same as for the :class:`Response` class and is not documented here.
:param encoding: is a string which contains the encoding to use for this
response. If you create a :class:`TextResponse` object with a unicode
body, it will be encoded using this encoding (remember the body attribute
is always a string). If ``encoding`` is ``None`` (default value), the
encoding will be looked up in the response headers and body instead.
:type encoding: string
response. If you create a :class:`TextResponse` object with a string as
body, it will be converted to bytes encoded using this encoding. If
*encoding* is ``None`` (default), the encoding will be looked up in the
response headers and body instead.
:type encoding: str
:class:`TextResponse` objects support the following attributes in addition
to the standard :class:`Response` ones:
.. attribute:: TextResponse.text
Response body, as unicode.
Response body, as a string.
The same as ``response.body.decode(response.encoding)``, but the
result is cached after the first call, so you can access
@ -777,9 +893,11 @@ TextResponse objects
.. note::
``unicode(response.body)`` is not a correct way to convert response
body to unicode: you would be using the system default encoding
(typically ``ascii``) instead of the response encoding.
``str(response.body)`` is not a correct way to convert the response
body into a string:
>>> str(b'body')
"b'body'"
.. attribute:: TextResponse.encoding
@ -824,10 +942,10 @@ TextResponse objects
.. automethod:: TextResponse.follow_all
.. method:: TextResponse.body_as_unicode()
.. automethod:: TextResponse.json()
The same as :attr:`text`, but available as a method. This method is
kept for backward compatibility; please prefer ``response.text``.
Returns a Python object from deserialized JSON document.
The result is cached after the first call.
HtmlResponse objects

34
docs/topics/scheduler.rst Normal file
View File

@ -0,0 +1,34 @@
.. _topics-scheduler:
=========
Scheduler
=========
.. module:: scrapy.core.scheduler
The scheduler component receives requests from the :ref:`engine <component-engine>`
and stores them into persistent and/or non-persistent data structures.
It also gets those requests and feeds them back to the engine when it
asks for a next request to be downloaded.
Overriding the default scheduler
================================
You can use your own custom scheduler class by supplying its full
Python path in the :setting:`SCHEDULER` setting.
Minimal scheduler interface
===========================
.. autoclass:: BaseScheduler
:members:
Default Scrapy scheduler
========================
.. autoclass:: Scheduler
:members:
:special-members: __len__

37
docs/topics/selectors.rst
View File

@ -8,14 +8,14 @@ When you're scraping web pages, the most common task you need to perform is
to extract data from the HTML source. There are several libraries available to
achieve this, such as:
* `BeautifulSoup`_ is a very popular web scraping library among Python
programmers which constructs a Python object based on the structure of the
HTML code and also deals with bad markup reasonably well, but it has one
drawback: it's slow.
- `BeautifulSoup`_ is a very popular web scraping library among Python
programmers which constructs a Python object based on the structure of the
HTML code and also deals with bad markup reasonably well, but it has one
drawback: it's slow.
* `lxml`_ is an XML parsing library (which also parses HTML) with a pythonic
API based on `ElementTree`_. (lxml is not part of the Python standard
library.)
- `lxml`_ is an XML parsing library (which also parses HTML) with a pythonic
API based on :mod:`~xml.etree.ElementTree`. (lxml is not part of the Python
standard library.)
Scrapy comes with its own mechanism for extracting data. They're called
selectors because they "select" certain parts of the HTML document specified
@ -36,7 +36,6 @@ defines selectors to associate those styles with specific HTML elements.
.. _BeautifulSoup: https://www.crummy.com/software/BeautifulSoup/
.. _lxml: https://lxml.de/
.. _ElementTree: https://docs.python.org/2/library/xml.etree.elementtree.html
.. _XPath: https://www.w3.org/TR/xpath/all/
.. _CSS: https://www.w3.org/TR/selectors
.. _parsel: https://parsel.readthedocs.io/en/latest/
@ -65,7 +64,8 @@ more shortcuts: ``response.xpath()`` and ``response.css()``:
Scrapy selectors are instances of :class:`~scrapy.selector.Selector` class
constructed by passing either :class:`~scrapy.http.TextResponse` object or
markup as an unicode string (in ``text`` argument).
markup as a string (in ``text`` argument).
Usually there is no need to construct Scrapy selectors manually:
``response`` object is available in Spider callbacks, so in most cases
it is more convenient to use ``response.css()`` and ``response.xpath()``
@ -328,8 +328,9 @@ too. Here's an example:
'<a href="image5.html">Name: My image 5 <br><img src="image5_thumb.jpg"></a>']
>>> for index, link in enumerate(links):
... args = (index, link.xpath('@href').get(), link.xpath('img/@src').get())
... print('Link number %d points to url %r and image %r' % args)
... href_xpath = link.xpath('@href').get()
... img_xpath = link.xpath('img/@src').get()
... print(f'Link number {index} points to url {href_xpath!r} and image {img_xpath!r}')
Link number 0 points to url 'image1.html' and image 'image1_thumb.jpg'
Link number 1 points to url 'image2.html' and image 'image2_thumb.jpg'
Link number 2 points to url 'image3.html' and image 'image3_thumb.jpg'
@ -384,7 +385,7 @@ Using selectors with regular expressions
:class:`~scrapy.selector.Selector` also has a ``.re()`` method for extracting
data using regular expressions. However, unlike using ``.xpath()`` or
``.css()`` methods, ``.re()`` returns a list of unicode strings. So you
``.css()`` methods, ``.re()`` returns a list of strings. So you
can't construct nested ``.re()`` calls.
Here's an example used to extract image names from the :ref:`HTML code
@ -463,10 +464,10 @@ effectively. If you are not much familiar with XPath yet,
you may want to take a look first at this `XPath tutorial`_.
.. note::
Some of the tips are based on `this post from ScrapingHub's blog`_.
Some of the tips are based on `this post from Zyte's blog`_.
.. _`XPath tutorial`: http://www.zvon.org/comp/r/tut-XPath_1.html
.. _`this post from ScrapingHub's blog`: https://blog.scrapinghub.com/2014/07/17/xpath-tips-from-the-web-scraping-trenches/
.. _this post from Zyte's blog: https://www.zyte.com/blog/xpath-tips-from-the-web-scraping-trenches/
.. _topics-selectors-relative-xpaths:
@ -735,7 +736,7 @@ The ``test()`` function, for example, can prove quite useful when XPath's
Example selecting links in list item with a "class" attribute ending with a digit:
>>> from scrapy import Selector
>>> doc = u"""
>>> doc = """
... <div>
... <ul>
... <li class="item-0"><a href="link1.html">first item</a></li>
@ -766,7 +767,7 @@ extracting text elements for example.
Example extracting microdata (sample content taken from https://schema.org/Product)
with groups of itemscopes and corresponding itemprops::
>>> doc = u"""
>>> doc = """
... <div itemscope itemtype="http://schema.org/Product">
... <span itemprop="name">Kenmore White 17" Microwave</span>
... <img src="kenmore-microwave-17in.jpg" alt='Kenmore 17" Microwave' />
@ -822,7 +823,7 @@ with groups of itemscopes and corresponding itemprops::
... props = scope.xpath('''
... set:difference(./descendant::*/@itemprop,
... .//*[@itemscope]/*/@itemprop)''')
... print(" properties: %s" % (props.getall()))
... print(f" properties: {props.getall()}")
... print("")
current scope: ['http://schema.org/Product']
@ -990,7 +991,7 @@ a :class:`~scrapy.http.HtmlResponse` object like this::
sel.xpath("//h1")
2. Extract the text of all ``<h1>`` elements from an HTML response body,
returning a list of unicode strings::
returning a list of strings::
sel.xpath("//h1").getall() # this includes the h1 tag
sel.xpath("//h1/text()").getall() # this excludes the h1 tag

212
docs/topics/settings.rst
View File

@ -26,9 +26,7 @@ do this by using an environment variable, ``SCRAPY_SETTINGS_MODULE``.
The value of ``SCRAPY_SETTINGS_MODULE`` should be in Python path syntax, e.g.
``myproject.settings``. Note that the settings module should be on the
Python `import search path`_.
.. _import search path: https://docs.python.org/2/tutorial/modules.html#the-module-search-path
Python :ref:`import search path <tut-searchpath>`.
.. _populating-settings:
@ -100,6 +98,32 @@ class.
The global defaults are located in the ``scrapy.settings.default_settings``
module and documented in the :ref:`topics-settings-ref` section.
Import paths and classes
========================
.. versionadded:: 2.4.0
When a setting references a callable object to be imported by Scrapy, such as a
class or a function, there are two different ways you can specify that object:
- As a string containing the import path of that object
- As the object itself
For example::
from mybot.pipelines.validate import ValidateMyItem
ITEM_PIPELINES = {
# passing the classname...
ValidateMyItem: 300,
# ...equals passing the class path
'mybot.pipelines.validate.ValidateMyItem': 300,
}
.. note:: Passing non-callable objects is not supported.
How to access settings
======================
@ -112,7 +136,7 @@ In a spider, the settings are available through ``self.settings``::
start_urls = ['http://example.com']
def parse(self, response):
print("Existing settings: %s" % self.settings.attributes.keys())
print(f"Existing settings: {self.settings.attributes.keys()}")
.. note::
The ``settings`` attribute is set in the base Spider class after the spider
@ -218,6 +242,32 @@ Default: ``None``
The name of the region associated with the AWS client.
.. setting:: ASYNCIO_EVENT_LOOP
ASYNCIO_EVENT_LOOP
------------------
Default: ``None``
Import path of a given ``asyncio`` event loop class.
If the asyncio reactor is enabled (see :setting:`TWISTED_REACTOR`) this setting can be used to specify the
asyncio event loop to be used with it. Set the setting to the import path of the
desired asyncio event loop class. If the setting is set to ``None`` the default asyncio
event loop will be used.
If you are installing the asyncio reactor manually using the :func:`~scrapy.utils.reactor.install_reactor`
function, you can use the ``event_loop_path`` parameter to indicate the import path of the event loop
class to be used.
Note that the event loop class must inherit from :class:`asyncio.AbstractEventLoop`.
.. caution:: Please be aware that, when using a non-default event loop
(either defined via :setting:`ASYNCIO_EVENT_LOOP` or installed with
:func:`~scrapy.utils.reactor.install_reactor`), Scrapy will call
:func:`asyncio.set_event_loop`, which will set the specified event loop
as the current loop for the current OS thread.
.. setting:: BOT_NAME
BOT_NAME
@ -238,8 +288,8 @@ CONCURRENT_ITEMS
Default: ``100``
Maximum number of concurrent items (per response) to process in parallel in the
Item Processor (also known as the :ref:`Item Pipeline <topics-item-pipeline>`).
Maximum number of concurrent items (per response) to process in parallel in
:ref:`item pipelines <topics-item-pipeline>`.
.. setting:: CONCURRENT_REQUESTS
@ -308,6 +358,11 @@ Default::
The default headers used for Scrapy HTTP Requests. They're populated in the
:class:`~scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware`.
.. caution:: Cookies set via the ``Cookie`` header are not considered by the
:ref:`cookies-mw`. If you need to set cookies for a request, use the
:class:`Request.cookies <scrapy.http.Request>` parameter. This is a known
current limitation that is being worked on.
.. setting:: DEPTH_LIMIT
DEPTH_LIMIT
@ -422,10 +477,9 @@ connections (for ``HTTP10DownloadHandler``).
.. note::
HTTP/1.0 is rarely used nowadays so you can safely ignore this setting,
unless you use Twisted<11.1, or if you really want to use HTTP/1.0
and override :setting:`DOWNLOAD_HANDLERS_BASE` for ``http(s)`` scheme
accordingly, i.e. to
``'scrapy.core.downloader.handlers.http.HTTP10DownloadHandler'``.
unless you really want to use HTTP/1.0 and override
:setting:`DOWNLOAD_HANDLERS` for ``http(s)`` scheme accordingly,
i.e. to ``'scrapy.core.downloader.handlers.http.HTTP10DownloadHandler'``.
.. setting:: DOWNLOADER_CLIENTCONTEXTFACTORY
@ -449,7 +503,6 @@ or even enable client-side authentication (and various other things).
Scrapy also has another context factory class that you can set,
``'scrapy.core.downloader.contextfactory.BrowserLikeContextFactory'``,
which uses the platform's certificates to validate remote endpoints.
**This is only available if you use Twisted>=14.0.**
If you do use a custom ContextFactory, make sure its ``__init__`` method
accepts a ``method`` parameter (this is the ``OpenSSL.SSL`` method mapping
@ -473,7 +526,7 @@ necessary to access certain HTTPS websites: for example, you may need to use
``'DEFAULT:!DH'`` for a website with weak DH parameters or enable a
specific cipher that is not included in ``DEFAULT`` if a website requires it.
.. _OpenSSL cipher list format: https://www.openssl.org/docs/manmaster/man1/ciphers.html#CIPHER-LIST-FORMAT
.. _OpenSSL cipher list format: https://www.openssl.org/docs/manmaster/man1/openssl-ciphers.html#CIPHER-LIST-FORMAT
.. setting:: DOWNLOADER_CLIENT_TLS_METHOD
@ -496,10 +549,6 @@ This setting must be one of these string values:
- ``'TLSv1.2'``: forces TLS version 1.2
- ``'SSLv3'``: forces SSL version 3 (**not recommended**)
.. note::
We recommend that you use PyOpenSSL>=0.13 and Twisted>=0.13
or above (Twisted>=14.0 if you can).
.. setting:: DOWNLOADER_CLIENT_TLS_VERBOSE_LOGGING
@ -608,6 +657,7 @@ DOWNLOAD_HANDLERS_BASE
Default::
{
'data': 'scrapy.core.downloader.handlers.datauri.DataURIDownloadHandler',
'file': 'scrapy.core.downloader.handlers.file.FileDownloadHandler',
'http': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler',
'https': 'scrapy.core.downloader.handlers.http.HTTPDownloadHandler',
@ -628,6 +678,45 @@ handler (without replacement), place this in your ``settings.py``::
'ftp': None,
}
.. _http2:
The default HTTPS handler uses HTTP/1.1. To use HTTP/2:
#. Install ``Twisted[http2]>=17.9.0`` to install the packages required to
enable HTTP/2 support in Twisted.
#. Update :setting:`DOWNLOAD_HANDLERS` as follows::
DOWNLOAD_HANDLERS = {
'https': 'scrapy.core.downloader.handlers.http2.H2DownloadHandler',
}
.. warning::
HTTP/2 support in Scrapy is experimental, and not yet recommended for
production environments. Future Scrapy versions may introduce related
changes without a deprecation period or warning.
.. note::
Known limitations of the current HTTP/2 implementation of Scrapy include:
- No support for HTTP/2 Cleartext (h2c), since no major browser supports
HTTP/2 unencrypted (refer `http2 faq`_).
- No setting to specify a maximum `frame size`_ larger than the default
value, 16384. Connections to servers that send a larger frame will
fail.
- No support for `server pushes`_, which are ignored.
- No support for the :signal:`bytes_received` and
:signal:`headers_received` signals.
.. _frame size: https://tools.ietf.org/html/rfc7540#section-4.2
.. _http2 faq: https://http2.github.io/faq/#does-http2-require-encryption
.. _server pushes: https://tools.ietf.org/html/rfc7540#section-8.2
.. setting:: DOWNLOAD_TIMEOUT
DOWNLOAD_TIMEOUT
@ -662,8 +751,6 @@ If you want to disable it set to 0.
spider attribute and per-request using :reqmeta:`download_maxsize`
Request.meta key.
This feature needs Twisted >= 11.1.
.. setting:: DOWNLOAD_WARNSIZE
DOWNLOAD_WARNSIZE
@ -681,8 +768,6 @@ If you want to disable it set to 0.
spider attribute and per-request using :reqmeta:`download_warnsize`
Request.meta key.
This feature needs Twisted >= 11.1.
.. setting:: DOWNLOAD_FAIL_ON_DATALOSS
DOWNLOAD_FAIL_ON_DATALOSS
@ -709,6 +794,15 @@ Optionally, this can be set per-request basis by using the
If :setting:`RETRY_ENABLED` is ``True`` and this setting is set to ``True``,
the ``ResponseFailed([_DataLoss])`` failure will be retried as usual.
.. warning::
This setting is ignored by the
:class:`~scrapy.core.downloader.handlers.http2.H2DownloadHandler`
download handler (see :setting:`DOWNLOAD_HANDLERS`). In case of a data loss
error, the corresponding HTTP/2 connection may be corrupted, affecting other
requests that use the same connection; hence, a ``ResponseFailed([InvalidBodyLengthError])``
failure is always raised for every request that was using that connection.
.. setting:: DUPEFILTER_CLASS
DUPEFILTER_CLASS
@ -798,6 +892,14 @@ The Feed Temp dir allows you to set a custom folder to save crawler
temporary files before uploading with :ref:`FTP feed storage <topics-feed-storage-ftp>` and
:ref:`Amazon S3 <topics-feed-storage-s3>`.
.. setting:: FEED_STORAGE_GCS_ACL
FEED_STORAGE_GCS_ACL
--------------------
The Access Control List (ACL) used when storing items to :ref:`Google Cloud Storage <topics-feed-storage-gcs>`.
For more information on how to set this value, please refer to the column *JSON API* in `Google Cloud documentation <https://cloud.google.com/storage/docs/access-control/lists>`_.
.. setting:: FTP_PASSIVE_MODE
FTP_PASSIVE_MODE
@ -837,6 +939,15 @@ Default: ``"anonymous"``
The username to use for FTP connections when there is no ``"ftp_user"``
in ``Request`` meta.
.. setting:: GCS_PROJECT_ID
GCS_PROJECT_ID
-----------------
Default: ``None``
The Project ID that will be used when storing data on `Google Cloud Storage`_.
.. setting:: ITEM_PIPELINES
ITEM_PIPELINES
@ -899,10 +1010,9 @@ LOG_FORMAT
Default: ``'%(asctime)s [%(name)s] %(levelname)s: %(message)s'``
String for formatting log messages. Refer to the `Python logging documentation`_ for the whole list of available
placeholders.
.. _Python logging documentation: https://docs.python.org/2/library/logging.html#logrecord-attributes
String for formatting log messages. Refer to the
:ref:`Python logging documentation <logrecord-attributes>` for the qwhole
list of available placeholders.
.. setting:: LOG_DATEFORMAT
@ -912,10 +1022,9 @@ LOG_DATEFORMAT
Default: ``'%Y-%m-%d %H:%M:%S'``
String for formatting date/time, expansion of the ``%(asctime)s`` placeholder
in :setting:`LOG_FORMAT`. Refer to the `Python datetime documentation`_ for the whole list of available
directives.
.. _Python datetime documentation: https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
in :setting:`LOG_FORMAT`. Refer to the
:ref:`Python datetime documentation <strftime-strptime-behavior>` for the
whole list of available directives.
.. setting:: LOG_FORMATTER
@ -1027,8 +1136,6 @@ See :ref:`topics-extensions-ref-memusage`.
MEMUSAGE_CHECK_INTERVAL_SECONDS
-------------------------------
.. versionadded:: 1.1
Default: ``60.0``
Scope: ``scrapy.extensions.memusage``
@ -1116,17 +1223,6 @@ multi-purpose thread pool used by various Scrapy components. Threaded
DNS Resolver, BlockingFeedStorage, S3FilesStore just to name a few. Increase
this value if you're experiencing problems with insufficient blocking IO.
.. setting:: REDIRECT_MAX_TIMES
REDIRECT_MAX_TIMES
------------------
Default: ``20``
Defines the maximum times a request can be redirected. After this maximum the
request's response is returned as is. We used Firefox default value for the
same task.
.. setting:: REDIRECT_PRIORITY_ADJUST
REDIRECT_PRIORITY_ADJUST
@ -1141,20 +1237,6 @@ Adjust redirect request priority relative to original request:
- **a positive priority adjust (default) means higher priority.**
- a negative priority adjust means lower priority.
.. setting:: RETRY_PRIORITY_ADJUST
RETRY_PRIORITY_ADJUST
---------------------
Default: ``-1``
Scope: ``scrapy.downloadermiddlewares.retry.RetryMiddleware``
Adjust retry request priority relative to original request:
- a positive priority adjust means higher priority.
- **a negative priority adjust (default) means lower priority.**
.. setting:: ROBOTSTXT_OBEY
ROBOTSTXT_OBEY
@ -1202,7 +1284,8 @@ SCHEDULER
Default: ``'scrapy.core.scheduler.Scheduler'``
The scheduler to use for crawling.
The scheduler class to be used for crawling.
See the :ref:`topics-scheduler` topic for details.
.. setting:: SCHEDULER_DEBUG
@ -1320,8 +1403,6 @@ The class that will be used for loading spiders, which must implement the
SPIDER_LOADER_WARN_ONLY
-----------------------
.. versionadded:: 1.3.3
Default: ``False``
By default, when Scrapy tries to import spider classes from :setting:`SPIDER_MODULES`,
@ -1422,17 +1503,6 @@ Default: ``True``
A boolean which specifies if the :ref:`telnet console <topics-telnetconsole>`
will be enabled (provided its extension is also enabled).
.. setting:: TELNETCONSOLE_PORT
TELNETCONSOLE_PORT
------------------
Default: ``[6023, 6073]``
The port range to use for the telnet console. If set to ``None`` or ``0``, a
dynamically assigned port is used. For more info see
:ref:`topics-telnetconsole`.
.. setting:: TEMPLATES_DIR
TEMPLATES_DIR
@ -1553,7 +1623,7 @@ Default: ``2083``
Scope: ``spidermiddlewares.urllength``
The maximum URL length to allow for crawled URLs. For more information about
the default value for this setting see: https://boutell.com/newfaq/misc/urllength.html
the default value for this setting see: https://support.microsoft.com/en-us/topic/maximum-url-length-is-2-083-characters-in-internet-explorer-174e7c8a-6666-f4e0-6fd6-908b53c12246
.. setting:: USER_AGENT
@ -1576,7 +1646,7 @@ case to see how to enable and use them.
.. settingslist::
.. _Amazon web services: https://aws.amazon.com/
.. _breadth-first order: https://en.wikipedia.org/wiki/Breadth-first_search
.. _depth-first order: https://en.wikipedia.org/wiki/Depth-first_search
.. _Google Cloud Storage: https://cloud.google.com/storage/

56
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@ -95,20 +95,21 @@ convenience.
Available Shortcuts
-------------------
* ``shelp()`` - print a help with the list of available objects and shortcuts
- ``shelp()`` - print a help with the list of available objects and
shortcuts
* ``fetch(url[, redirect=True])`` - fetch a new response from the given
URL and update all related objects accordingly. You can optionaly ask for
HTTP 3xx redirections to not be followed by passing ``redirect=False``
- ``fetch(url[, redirect=True])`` - fetch a new response from the given URL
and update all related objects accordingly. You can optionaly ask for HTTP
3xx redirections to not be followed by passing ``redirect=False``
* ``fetch(request)`` - fetch a new response from the given request and
update all related objects accordingly.
- ``fetch(request)`` - fetch a new response from the given request and update
all related objects accordingly.
* ``view(response)`` - open the given response in your local web browser, for
inspection. This will add a `\<base\> tag`_ to the response body in order
for external links (such as images and style sheets) to display properly.
Note, however, that this will create a temporary file in your computer,
which won't be removed automatically.
- ``view(response)`` - open the given response in your local web browser, for
inspection. This will add a `\<base\> tag`_ to the response body in order
for external links (such as images and style sheets) to display properly.
Note, however, that this will create a temporary file in your computer,
which won't be removed automatically.
.. _<base> tag: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
@ -122,21 +123,21 @@ content).
Those objects are:
* ``crawler`` - the current :class:`~scrapy.crawler.Crawler` object.
- ``crawler`` - the current :class:`~scrapy.crawler.Crawler` object.
* ``spider`` - the Spider which is known to handle the URL, or a
:class:`~scrapy.spiders.Spider` object if there is no spider found for
the current URL
- ``spider`` - the Spider which is known to handle the URL, or a
:class:`~scrapy.spiders.Spider` object if there is no spider found for the
current URL
* ``request`` - a :class:`~scrapy.http.Request` object of the last fetched
page. You can modify this request using :meth:`~scrapy.http.Request.replace`
or fetch a new request (without leaving the shell) using the ``fetch``
shortcut.
- ``request`` - a :class:`~scrapy.http.Request` object of the last fetched
page. You can modify this request using
:meth:`~scrapy.http.Request.replace` or fetch a new request (without
leaving the shell) using the ``fetch`` shortcut.
* ``response`` - a :class:`~scrapy.http.Response` object containing the last
fetched page
- ``response`` - a :class:`~scrapy.http.Response` object containing the last
fetched page
* ``settings`` - the current :ref:`Scrapy settings <topics-settings>`
- ``settings`` - the current :ref:`Scrapy settings <topics-settings>`
Example of shell session
========================
@ -156,6 +157,17 @@ First, we launch the shell::
scrapy shell 'https://scrapy.org' --nolog
.. note::
Remember to always enclose URLs in quotes when running the Scrapy shell from
the command line, otherwise URLs containing arguments (i.e. the ``&`` character)
will not work.
On Windows, use double quotes instead::
scrapy shell "https://scrapy.org" --nolog
Then, the shell fetches the URL (using the Scrapy downloader) and prints the
list of available objects and useful shortcuts (you'll notice that these lines
all start with the ``[s]`` prefix)::

199
docs/topics/signals.rst
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@ -16,8 +16,7 @@ deliver the arguments that the handler receives.
You can connect to signals (or send your own) through the
:ref:`topics-api-signals`.
Here is a simple example showing how you can catch signals and perform some action:
::
Here is a simple example showing how you can catch signals and perform some action::
from scrapy import signals
from scrapy import Spider
@ -52,9 +51,45 @@ Deferred signal handlers
========================
Some signals support returning :class:`~twisted.internet.defer.Deferred`
objects from their handlers, see the :ref:`topics-signals-ref` below to know
which ones.
objects from their handlers, allowing you to run asynchronous code that
does not block Scrapy. If a signal handler returns a
:class:`~twisted.internet.defer.Deferred`, Scrapy waits for that
:class:`~twisted.internet.defer.Deferred` to fire.
Let's take an example::
class SignalSpider(scrapy.Spider):
name = 'signals'
start_urls = ['http://quotes.toscrape.com/page/1/']
@classmethod
def from_crawler(cls, crawler, *args, **kwargs):
spider = super(SignalSpider, cls).from_crawler(crawler, *args, **kwargs)
crawler.signals.connect(spider.item_scraped, signal=signals.item_scraped)
return spider
def item_scraped(self, item):
# Send the scraped item to the server
d = treq.post(
'http://example.com/post',
json.dumps(item).encode('ascii'),
headers={b'Content-Type': [b'application/json']}
)
# The next item will be scraped only after
# deferred (d) is fired
return d
def parse(self, response):
for quote in response.css('div.quote'):
yield {
'text': quote.css('span.text::text').get(),
'author': quote.css('small.author::text').get(),
'tags': quote.css('div.tags a.tag::text').getall(),
}
See the :ref:`topics-signals-ref` below to know which signals support
:class:`~twisted.internet.defer.Deferred`.
.. _topics-signals-ref:
@ -66,22 +101,25 @@ Built-in signals reference
Here's the list of Scrapy built-in signals and their meaning.
engine_started
Engine signals
--------------
engine_started
~~~~~~~~~~~~~~
.. signal:: engine_started
.. function:: engine_started()
Sent when the Scrapy engine has started crawling.
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
.. note:: This signal may be fired *after* the :signal:`spider_opened` signal,
depending on how the spider was started. So **don't** rely on this signal
getting fired before :signal:`spider_opened`.
engine_stopped
--------------
~~~~~~~~~~~~~~
.. signal:: engine_stopped
.. function:: engine_stopped()
@ -89,10 +127,21 @@ engine_stopped
Sent when the Scrapy engine is stopped (for example, when a crawling
process has finished).
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
Item signals
------------
.. note::
As at max :setting:`CONCURRENT_ITEMS` items are processed in
parallel, many deferreds are fired together using
:class:`~twisted.internet.defer.DeferredList`. Hence the next
batch waits for the :class:`~twisted.internet.defer.DeferredList`
to fire and then runs the respective item signal handler for
the next batch of scraped items.
item_scraped
------------
~~~~~~~~~~~~
.. signal:: item_scraped
.. function:: item_scraped(item, response, spider)
@ -100,10 +149,10 @@ item_scraped
Sent when an item has been scraped, after it has passed all the
:ref:`topics-item-pipeline` stages (without being dropped).
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
:param item: the item scraped
:type item: dict or :class:`~scrapy.item.Item` object
:param item: the scraped item
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -112,7 +161,7 @@ item_scraped
:type response: :class:`~scrapy.http.Response` object
item_dropped
------------
~~~~~~~~~~~~
.. signal:: item_dropped
.. function:: item_dropped(item, response, exception, spider)
@ -120,10 +169,10 @@ item_dropped
Sent after an item has been dropped from the :ref:`topics-item-pipeline`
when some stage raised a :exc:`~scrapy.exceptions.DropItem` exception.
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
:param item: the item dropped from the :ref:`topics-item-pipeline`
:type item: dict or :class:`~scrapy.item.Item` object
:type item: :ref:`item object <item-types>`
:param spider: the spider which scraped the item
:type spider: :class:`~scrapy.spiders.Spider` object
@ -137,7 +186,7 @@ item_dropped
:type exception: :exc:`~scrapy.exceptions.DropItem` exception
item_error
------------
~~~~~~~~~~
.. signal:: item_error
.. function:: item_error(item, response, spider, failure)
@ -145,10 +194,10 @@ item_error
Sent when a :ref:`topics-item-pipeline` generates an error (i.e. raises
an exception), except :exc:`~scrapy.exceptions.DropItem` exception.
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
:param item: the item dropped from the :ref:`topics-item-pipeline`
:type item: dict or :class:`~scrapy.item.Item` object
:param item: the item that caused the error in the :ref:`topics-item-pipeline`
:type item: :ref:`item object <item-types>`
:param response: the response being processed when the exception was raised
:type response: :class:`~scrapy.http.Response` object
@ -159,8 +208,11 @@ item_error
:param failure: the exception raised
:type failure: twisted.python.failure.Failure
Spider signals
--------------
spider_closed
-------------
~~~~~~~~~~~~~
.. signal:: spider_closed
.. function:: spider_closed(spider, reason)
@ -168,7 +220,7 @@ spider_closed
Sent after a spider has been closed. This can be used to release per-spider
resources reserved on :signal:`spider_opened`.
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
:param spider: the spider which has been closed
:type spider: :class:`~scrapy.spiders.Spider` object
@ -183,7 +235,7 @@ spider_closed
:type reason: str
spider_opened
-------------
~~~~~~~~~~~~~
.. signal:: spider_opened
.. function:: spider_opened(spider)
@ -192,13 +244,13 @@ spider_opened
reserve per-spider resources, but can be used for any task that needs to be
performed when a spider is opened.
This signal supports returning deferreds from their handlers.
This signal supports returning deferreds from its handlers.
:param spider: the spider which has been opened
:type spider: :class:`~scrapy.spiders.Spider` object
spider_idle
-----------
~~~~~~~~~~~
.. signal:: spider_idle
.. function:: spider_idle(spider)
@ -216,7 +268,7 @@ spider_idle
You may raise a :exc:`~scrapy.exceptions.DontCloseSpider` exception to
prevent the spider from being closed.
This signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param spider: the spider which has gone idle
:type spider: :class:`~scrapy.spiders.Spider` object
@ -228,14 +280,14 @@ spider_idle
due to duplication).
spider_error
------------
~~~~~~~~~~~~
.. signal:: spider_error
.. function:: spider_error(failure, response, spider)
Sent when a spider callback generates an error (i.e. raises an exception).
This signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param failure: the exception raised
:type failure: twisted.python.failure.Failure
@ -246,8 +298,11 @@ spider_error
:param spider: the spider which raised the exception
:type spider: :class:`~scrapy.spiders.Spider` object
Request signals
---------------
request_scheduled
-----------------
~~~~~~~~~~~~~~~~~
.. signal:: request_scheduled
.. function:: request_scheduled(request, spider)
@ -255,7 +310,7 @@ request_scheduled
Sent when the engine schedules a :class:`~scrapy.http.Request`, to be
downloaded later.
The signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param request: the request that reached the scheduler
:type request: :class:`~scrapy.http.Request` object
@ -264,7 +319,7 @@ request_scheduled
:type spider: :class:`~scrapy.spiders.Spider` object
request_dropped
---------------
~~~~~~~~~~~~~~~
.. signal:: request_dropped
.. function:: request_dropped(request, spider)
@ -272,7 +327,7 @@ request_dropped
Sent when a :class:`~scrapy.http.Request`, scheduled by the engine to be
downloaded later, is rejected by the scheduler.
The signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param request: the request that reached the scheduler
:type request: :class:`~scrapy.http.Request` object
@ -281,14 +336,14 @@ request_dropped
:type spider: :class:`~scrapy.spiders.Spider` object
request_reached_downloader
---------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~
.. signal:: request_reached_downloader
.. function:: request_reached_downloader(request, spider)
Sent when a :class:`~scrapy.http.Request` reached downloader.
The signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param request: the request that reached downloader
:type request: :class:`~scrapy.http.Request` object
@ -297,7 +352,7 @@ request_reached_downloader
:type spider: :class:`~scrapy.spiders.Spider` object
request_left_downloader
-----------------------
~~~~~~~~~~~~~~~~~~~~~~~
.. signal:: request_left_downloader
.. function:: request_left_downloader(request, spider)
@ -315,8 +370,71 @@ request_left_downloader
:param spider: the spider that yielded the request
:type spider: :class:`~scrapy.spiders.Spider` object
bytes_received
~~~~~~~~~~~~~~
.. versionadded:: 2.2
.. signal:: bytes_received
.. function:: bytes_received(data, request, spider)
Sent by the HTTP 1.1 and S3 download handlers when a group of bytes is
received for a specific request. This signal might be fired multiple
times for the same request, with partial data each time. For instance,
a possible scenario for a 25 kb response would be two signals fired
with 10 kb of data, and a final one with 5 kb of data.
Handlers for this signal can stop the download of a response while it
is in progress by raising the :exc:`~scrapy.exceptions.StopDownload`
exception. Please refer to the :ref:`topics-stop-response-download` topic
for additional information and examples.
This signal does not support returning deferreds from its handlers.
:param data: the data received by the download handler
:type data: :class:`bytes` object
:param request: the request that generated the download
:type request: :class:`~scrapy.http.Request` object
:param spider: the spider associated with the response
:type spider: :class:`~scrapy.spiders.Spider` object
headers_received
~~~~~~~~~~~~~~~~
.. versionadded:: 2.5
.. signal:: headers_received
.. function:: headers_received(headers, request, spider)
Sent by the HTTP 1.1 and S3 download handlers when the response headers are
available for a given request, before downloading any additional content.
Handlers for this signal can stop the download of a response while it
is in progress by raising the :exc:`~scrapy.exceptions.StopDownload`
exception. Please refer to the :ref:`topics-stop-response-download` topic
for additional information and examples.
This signal does not support returning deferreds from its handlers.
:param headers: the headers received by the download handler
:type headers: :class:`scrapy.http.headers.Headers` object
:param body_length: expected size of the response body, in bytes
:type body_length: `int`
:param request: the request that generated the download
:type request: :class:`~scrapy.http.Request` object
:param spider: the spider associated with the response
:type spider: :class:`~scrapy.spiders.Spider` object
Response signals
----------------
response_received
-----------------
~~~~~~~~~~~~~~~~~
.. signal:: response_received
.. function:: response_received(response, request, spider)
@ -324,7 +442,7 @@ response_received
Sent when the engine receives a new :class:`~scrapy.http.Response` from the
downloader.
This signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param response: the response received
:type response: :class:`~scrapy.http.Response` object
@ -335,15 +453,20 @@ response_received
:param spider: the spider for which the response is intended
:type spider: :class:`~scrapy.spiders.Spider` object
.. note:: The ``request`` argument might not contain the original request that
reached the downloader, if a :ref:`topics-downloader-middleware` modifies
the :class:`~scrapy.http.Response` object and sets a specific ``request``
attribute.
response_downloaded
-------------------
~~~~~~~~~~~~~~~~~~~
.. signal:: response_downloaded
.. function:: response_downloaded(response, request, spider)
Sent by the downloader right after a ``HTTPResponse`` is downloaded.
This signal does not support returning deferreds from their handlers.
This signal does not support returning deferreds from its handlers.
:param response: the response downloaded
:type response: :class:`~scrapy.http.Response` object

32
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@ -102,29 +102,28 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
it has processed the response.
:meth:`process_spider_output` must return an iterable of
:class:`~scrapy.http.Request`, dict or :class:`~scrapy.item.Item`
objects.
:class:`~scrapy.http.Request` objects and :ref:`item object
<topics-items>`.
:param response: the response which generated this output from the
spider
:type response: :class:`~scrapy.http.Response` object
:param result: the result returned by the spider
:type result: an iterable of :class:`~scrapy.http.Request`, dict
or :class:`~scrapy.item.Item` objects
:type result: an iterable of :class:`~scrapy.http.Request` objects and
:ref:`item object <topics-items>`
:param spider: the spider whose result is being processed
:type spider: :class:`~scrapy.spiders.Spider` object
.. method:: process_spider_exception(response, exception, spider)
This method is called when a spider or :meth:`process_spider_output`
method (from a previous spider middleware) raises an exception.
:meth:`process_spider_exception` should return either ``None`` or an
iterable of :class:`~scrapy.http.Request`, dict or
:class:`~scrapy.item.Item` objects.
iterable of :class:`~scrapy.http.Request` objects and :ref:`item object
<topics-items>`.
If it returns ``None``, Scrapy will continue processing this exception,
executing any other :meth:`process_spider_exception` in the following
@ -140,15 +139,13 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
:type response: :class:`~scrapy.http.Response` object
:param exception: the exception raised
:type exception: `Exception`_ object
:type exception: :exc:`Exception` object
:param spider: the spider which raised the exception
:type spider: :class:`~scrapy.spiders.Spider` object
.. method:: process_start_requests(start_requests, spider)
.. versionadded:: 0.15
This method is called with the start requests of the spider, and works
similarly to the :meth:`process_spider_output` method, except that it
doesn't have a response associated and must return only requests (not
@ -173,20 +170,16 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
:type spider: :class:`~scrapy.spiders.Spider` object
.. method:: from_crawler(cls, crawler)
If present, this classmethod is called to create a middleware instance
from a :class:`~scrapy.crawler.Crawler`. It must return a new instance
of the middleware. Crawler object provides access to all Scrapy core
components like settings and signals; it is a way for middleware to
access them and hook its functionality into Scrapy.
:param crawler: crawler that uses this middleware
:type crawler: :class:`~scrapy.crawler.Crawler` object
.. _Exception: https://docs.python.org/2/library/exceptions.html#exceptions.Exception
.. _topics-spider-middleware-ref:
Built-in spider middleware reference
@ -260,7 +253,8 @@ this::
The ``handle_httpstatus_list`` key of :attr:`Request.meta
<scrapy.http.Request.meta>` can also be used to specify which response codes to
allow on a per-request basis. You can also set the meta key ``handle_httpstatus_all``
to ``True`` if you want to allow any response code for a request.
to ``True`` if you want to allow any response code for a request, and ``False`` to
disable the effects of the ``handle_httpstatus_all`` key.
Keep in mind, however, that it's usually a bad idea to handle non-200
responses, unless you really know what you're doing.
@ -346,8 +340,6 @@ RefererMiddleware settings
REFERER_ENABLED
^^^^^^^^^^^^^^^
.. versionadded:: 0.15
Default: ``True``
Whether to enable referer middleware.
@ -357,8 +349,6 @@ Whether to enable referer middleware.
REFERRER_POLICY
^^^^^^^^^^^^^^^
.. versionadded:: 1.4
Default: ``'scrapy.spidermiddlewares.referer.DefaultReferrerPolicy'``
.. reqmeta:: referrer_policy

61
docs/topics/spiders.rst
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@ -23,8 +23,8 @@ For spiders, the scraping cycle goes through something like this:
:attr:`~scrapy.spiders.Spider.parse` method as callback function for the
Requests.
2. In the callback function, you parse the response (web page) and return either
dicts with extracted data, :class:`~scrapy.item.Item` objects,
2. In the callback function, you parse the response (web page) and return
:ref:`item objects <topics-items>`,
:class:`~scrapy.http.Request` objects, or an iterable of these objects.
Those Requests will also contain a callback (maybe
the same) and will then be downloaded by Scrapy and then their
@ -121,7 +121,7 @@ scrapy.Spider
send log messages through it as described on
:ref:`topics-logging-from-spiders`.
.. method:: from_crawler(crawler, \*args, \**kwargs)
.. method:: from_crawler(crawler, *args, **kwargs)
This is the class method used by Scrapy to create your spiders.
@ -179,8 +179,8 @@ scrapy.Spider
the same requirements as the :class:`Spider` class.
This method, as well as any other Request callback, must return an
iterable of :class:`~scrapy.http.Request` and/or
dicts or :class:`~scrapy.item.Item` objects.
iterable of :class:`~scrapy.http.Request` and/or :ref:`item objects
<topics-items>`.
:param response: the response to parse
:type response: :class:`~scrapy.http.Response`
@ -234,7 +234,7 @@ Return multiple Requests and items from a single callback::
yield scrapy.Request(response.urljoin(href), self.parse)
Instead of :attr:`~.start_urls` you can use :meth:`~.start_requests` directly;
to give data more structure you can use :ref:`topics-items`::
to give data more structure you can use :class:`~scrapy.item.Item` objects::
import scrapy
from myproject.items import MyItem
@ -279,7 +279,7 @@ Spiders can access arguments in their `__init__` methods::
def __init__(self, category=None, *args, **kwargs):
super(MySpider, self).__init__(*args, **kwargs)
self.start_urls = ['http://www.example.com/categories/%s' % category]
self.start_urls = [f'http://www.example.com/categories/{category}']
# ...
The default `__init__` method will take any spider arguments
@ -292,15 +292,21 @@ The above example can also be written as follows::
name = 'myspider'
def start_requests(self):
yield scrapy.Request('http://www.example.com/categories/%s' % self.category)
yield scrapy.Request(f'http://www.example.com/categories/{self.category}')
If you are :ref:`running Scrapy from a script <run-from-script>`, you can
specify spider arguments when calling
:class:`CrawlerProcess.crawl <scrapy.crawler.CrawlerProcess.crawl>` or
:class:`CrawlerRunner.crawl <scrapy.crawler.CrawlerRunner.crawl>`::
process = CrawlerProcess()
process.crawl(MySpider, category="electronics")
Keep in mind that spider arguments are only strings.
The spider will not do any parsing on its own.
If you were to set the ``start_urls`` attribute from the command line,
you would have to parse it on your own into a list
using something like
`ast.literal_eval <https://docs.python.org/3/library/ast.html#ast.literal_eval>`_
or `json.loads <https://docs.python.org/3/library/json.html#json.loads>`_
using something like :func:`ast.literal_eval` or :func:`json.loads`
and then set it as an attribute.
Otherwise, you would cause iteration over a ``start_urls`` string
(a very common python pitfall)
@ -362,11 +368,12 @@ CrawlSpider
This spider also exposes an overrideable method:
.. method:: parse_start_url(response)
.. method:: parse_start_url(response, **kwargs)
This method is called for the start_urls responses. It allows to parse
This method is called for each response produced for the URLs in
the spider's ``start_urls`` attribute. It allows to parse
the initial responses and must return either an
:class:`~scrapy.item.Item` object, a :class:`~scrapy.http.Request`
:ref:`item object <topics-items>`, a :class:`~scrapy.http.Request`
object, or an iterable containing any of them.
Crawling rules
@ -385,16 +392,11 @@ Crawling rules
object with that name will be used) to be called for each link extracted with
the specified link extractor. This callback receives a :class:`~scrapy.http.Response`
as its first argument and must return either a single instance or an iterable of
:class:`~scrapy.item.Item`, ``dict`` and/or :class:`~scrapy.http.Request` objects
:ref:`item objects <topics-items>` and/or :class:`~scrapy.http.Request` objects
(or any subclass of them). As mentioned above, the received :class:`~scrapy.http.Response`
object will contain the text of the link that produced the :class:`~scrapy.http.Request`
in its ``meta`` dictionary (under the ``link_text`` key)
.. warning:: When writing crawl spider rules, avoid using ``parse`` as
callback, since the :class:`CrawlSpider` uses the ``parse`` method
itself to implement its logic. So if you override the ``parse`` method,
the crawl spider will no longer work.
``cb_kwargs`` is a dict containing the keyword arguments to be passed to the
callback function.
@ -420,6 +422,11 @@ Crawling rules
It receives a :class:`Twisted Failure <twisted.python.failure.Failure>`
instance as first parameter.
.. warning:: Because of its internal implementation, you must explicitly set
callbacks for new requests when writing :class:`CrawlSpider`-based spiders;
unexpected behaviour can occur otherwise.
.. versionadded:: 2.0
The *errback* parameter.
@ -453,6 +460,11 @@ Let's now take a look at an example CrawlSpider with rules::
item['name'] = response.xpath('//td[@id="item_name"]/text()').get()
item['description'] = response.xpath('//td[@id="item_description"]/text()').get()
item['link_text'] = response.meta['link_text']
url = response.xpath('//td[@id="additional_data"]/@href').get()
return response.follow(url, self.parse_additional_page, cb_kwargs=dict(item=item))
def parse_additional_page(self, response, item):
item['additional_data'] = response.xpath('//p[@id="additional_data"]/text()').get()
return item
@ -533,7 +545,7 @@ XMLFeedSpider
(``itertag``). Receives the response and an
:class:`~scrapy.selector.Selector` for each node. Overriding this
method is mandatory. Otherwise, you spider won't work. This method
must return either a :class:`~scrapy.item.Item` object, a
must return an :ref:`item object <topics-items>`, a
:class:`~scrapy.http.Request` object, or an iterable containing any of
them.
@ -543,7 +555,12 @@ XMLFeedSpider
spider, and it's intended to perform any last time processing required
before returning the results to the framework core, for example setting the
item IDs. It receives a list of results and the response which originated
those results. It must return a list of results (Items or Requests).
those results. It must return a list of results (items or requests).
.. warning:: Because of its internal implementation, you must explicitly set
callbacks for new requests when writing :class:`XMLFeedSpider`-based spiders;
unexpected behaviour can occur otherwise.
XMLFeedSpider example

14
docs/topics/telnetconsole.rst
View File

@ -40,10 +40,10 @@ the console you need to type::
Connected to localhost.
Escape character is '^]'.
Username:
Password:
Password:
>>>
By default Username is ``scrapy`` and Password is autogenerated. The
By default Username is ``scrapy`` and Password is autogenerated. The
autogenerated Password can be seen on Scrapy logs like the example below::
2018-10-16 14:35:21 [scrapy.extensions.telnet] INFO: Telnet Password: 16f92501e8a59326
@ -63,7 +63,7 @@ Available variables in the telnet console
=========================================
The telnet console is like a regular Python shell running inside the Scrapy
process, so you can do anything from it including importing new modules, etc.
process, so you can do anything from it including importing new modules, etc.
However, the telnet console comes with some default variables defined for
convenience:
@ -89,13 +89,11 @@ convenience:
+----------------+-------------------------------------------------------------------+
| ``prefs`` | for memory debugging (see :ref:`topics-leaks`) |
+----------------+-------------------------------------------------------------------+
| ``p`` | a shortcut to the `pprint.pprint`_ function |
| ``p`` | a shortcut to the :func:`pprint.pprint` function |
+----------------+-------------------------------------------------------------------+
| ``hpy`` | for memory debugging (see :ref:`topics-leaks`) |
+----------------+-------------------------------------------------------------------+
.. _pprint.pprint: https://docs.python.org/library/pprint.html#pprint.pprint
Telnet console usage examples
=============================
@ -112,11 +110,10 @@ using the telnet console::
Execution engine status
time()-engine.start_time : 8.62972998619
engine.has_capacity() : False
len(engine.downloader.active) : 16
engine.scraper.is_idle() : False
engine.spider.name : followall
engine.spider_is_idle(engine.spider) : False
engine.spider_is_idle() : False
engine.slot.closing : False
len(engine.slot.inprogress) : 16
len(engine.slot.scheduler.dqs or []) : 0
@ -208,4 +205,3 @@ Default: ``None``
The password used for the telnet console, default behaviour is to have it
autogenerated

85
docs/utils/linkfix.py
View File

@ -14,50 +14,57 @@ Author: dufferzafar
import re
# Used for remembering the file (and its contents)
# so we don't have to open the same file again.
_filename = None
_contents = None
# A regex that matches standard linkcheck output lines
line_re = re.compile(u'(.*)\:\d+\:\s\[(.*)\]\s(?:(.*)\sto\s(.*)|(.*))')
def main():
# Read lines from the linkcheck output file
try:
with open("build/linkcheck/output.txt") as out:
output_lines = out.readlines()
except IOError:
print("linkcheck output not found; please run linkcheck first.")
exit(1)
# Used for remembering the file (and its contents)
# so we don't have to open the same file again.
_filename = None
_contents = None
# For every line, fix the respective file
for line in output_lines:
match = re.match(line_re, line)
# A regex that matches standard linkcheck output lines
line_re = re.compile(r'(.*)\:\d+\:\s\[(.*)\]\s(?:(.*)\sto\s(.*)|(.*))')
if match:
newfilename = match.group(1)
errortype = match.group(2)
# Read lines from the linkcheck output file
try:
with open("build/linkcheck/output.txt") as out:
output_lines = out.readlines()
except IOError:
print("linkcheck output not found; please run linkcheck first.")
exit(1)
# Broken links can't be fixed and
# I am not sure what do with the local ones.
if errortype.lower() in ["broken", "local"]:
print("Not Fixed: " + line)
# For every line, fix the respective file
for line in output_lines:
match = re.match(line_re, line)
if match:
newfilename = match.group(1)
errortype = match.group(2)
# Broken links can't be fixed and
# I am not sure what do with the local ones.
if errortype.lower() in ["broken", "local"]:
print("Not Fixed: " + line)
else:
# If this is a new file
if newfilename != _filename:
# Update the previous file
if _filename:
with open(_filename, "w") as _file:
_file.write(_contents)
_filename = newfilename
# Read the new file to memory
with open(_filename) as _file:
_contents = _file.read()
_contents = _contents.replace(match.group(3), match.group(4))
else:
# If this is a new file
if newfilename != _filename:
# We don't understand what the current line means!
print("Not Understood: " + line)
# Update the previous file
if _filename:
with open(_filename, "w") as _file:
_file.write(_contents)
_filename = newfilename
# Read the new file to memory
with open(_filename) as _file:
_contents = _file.read()
_contents = _contents.replace(match.group(3), match.group(4))
else:
# We don't understand what the current line means!
print("Not Understood: " + line)
if __name__ == '__main__':
main()

22
docs/versioning.rst
View File

@ -1,7 +1,7 @@
.. _versioning:
============================
Versioning and API Stability
Versioning and API stability
============================
Versioning
@ -34,7 +34,7 @@ For example:
production)
API Stability
API stability
=============
API stability was one of the major goals for the *1.0* release.
@ -47,5 +47,23 @@ new methods or functionality but the existing methods should keep working the
same way.
.. _deprecation-policy:
Deprecation policy
==================
We aim to maintain support for deprecated Scrapy features for at least 1 year.
For example, if a feature is deprecated in a Scrapy version released on
June 15th 2020, that feature should continue to work in versions released on
June 14th 2021 or before that.
Any new Scrapy release after a year *may* remove support for that deprecated
feature.
All deprecated features removed in a Scrapy release are explicitly mentioned in
the :ref:`release notes <news>`.
.. _odd-numbered versions for development releases: https://en.wikipedia.org/wiki/Software_versioning#Odd-numbered_versions_for_development_releases

2
extras/qps-bench-server.py
View File

@ -37,7 +37,7 @@ class Root(Resource):
if now - self.lastmark >= 3:
self.lastmark = now
qps = len(self.tail) / sum(self.tail)
print('samplesize={0} concurrent={1} qps={2:0.2f}'.format(len(self.tail), self.concurrent, qps))
print(f'samplesize={len(self.tail)} concurrent={self.concurrent} qps={qps:0.2f}')
if 'latency' in request.args:
latency = float(request.args['latency'][0])

6
extras/qpsclient.py
View File

@ -27,7 +27,7 @@ class QPSSpider(Spider):
slots = 1
def __init__(self, *a, **kw):
super(QPSSpider, self).__init__(*a, **kw)
super().__init__(*a, **kw)
if self.qps is not None:
self.qps = float(self.qps)
self.download_delay = 1 / self.qps
@ -37,11 +37,11 @@ class QPSSpider(Spider):
def start_requests(self):
url = self.benchurl
if self.latency is not None:
url += '?latency={0}'.format(self.latency)
url += f'?latency={self.latency}'
slots = int(self.slots)
if slots > 1:
urls = [url.replace('localhost', '127.0.0.%d' % (x + 1)) for x in range(slots)]
urls = [url.replace('localhost', f'127.0.0.{x + 1}') for x in range(slots)]
else:
urls = [url]

116
pylintrc Normal file
View File

@ -0,0 +1,116 @@
[MASTER]
persistent=no
jobs=1 # >1 hides results
[MESSAGES CONTROL]
disable=abstract-method,
anomalous-backslash-in-string,
arguments-differ,
attribute-defined-outside-init,
bad-classmethod-argument,
bad-continuation,
bad-indentation,
bad-mcs-classmethod-argument,
bad-super-call,
bad-whitespace,
bare-except,
blacklisted-name,
broad-except,
c-extension-no-member,
catching-non-exception,
cell-var-from-loop,
comparison-with-callable,
consider-iterating-dictionary,
consider-using-in,
consider-using-set-comprehension,
consider-using-sys-exit,
consider-using-with,
cyclic-import,
dangerous-default-value,
deprecated-method,
deprecated-module,
duplicate-code, # https://github.com/PyCQA/pylint/issues/214
eval-used,
expression-not-assigned,
fixme,
function-redefined,
global-statement,
import-error,
import-outside-toplevel,
import-self,
inconsistent-return-statements,
inherit-non-class,
invalid-name,
invalid-overridden-method,
isinstance-second-argument-not-valid-type,
keyword-arg-before-vararg,
line-too-long,
logging-format-interpolation,
logging-not-lazy,
lost-exception,
method-hidden,
misplaced-comparison-constant,
missing-docstring,
missing-final-newline,
multiple-imports,
multiple-statements,
no-else-continue,
no-else-raise,
no-else-return,
no-init,
no-member,
no-method-argument,
no-name-in-module,
no-self-argument,
no-self-use,
no-value-for-parameter,
not-an-iterable,
not-callable,
pointless-statement,
pointless-string-statement,
protected-access,
raise-missing-from,
redefined-argument-from-local,
redefined-builtin,
redefined-outer-name,
reimported,
signature-differs,
singleton-comparison,
super-init-not-called,
super-with-arguments,
superfluous-parens,
too-few-public-methods,
too-many-ancestors,
too-many-arguments,
too-many-branches,
too-many-format-args,
too-many-function-args,
too-many-instance-attributes,
too-many-lines,
too-many-locals,
too-many-public-methods,
too-many-return-statements,
trailing-newlines,
trailing-whitespace,
unbalanced-tuple-unpacking,
undefined-variable,
undefined-loop-variable,
unexpected-special-method-signature,
ungrouped-imports,
unidiomatic-typecheck,
unnecessary-comprehension,
unnecessary-lambda,
unnecessary-pass,
unreachable,
unsubscriptable-object,
unused-argument,
unused-import,
unused-variable,
unused-wildcard-import,
used-before-assignment,
useless-object-inheritance, # Required for Python 2 support
useless-return,
useless-super-delegation,
wildcard-import,
wrong-import-order,
wrong-import-position

233
pytest.ini
View File

@ -1,4 +1,5 @@
[pytest]
xfail_strict = true
usefixtures = chdir
python_files=test_*.py __init__.py
python_classes=
@ -17,235 +18,7 @@ addopts =
--ignore=docs/topics/stats.rst
--ignore=docs/topics/telnetconsole.rst
--ignore=docs/utils
twisted = 1
markers =
only_asyncio: marks tests as only enabled when --reactor=asyncio is passed
flake8-ignore =
W503
# Files that are only meant to provide top-level imports are expected not
# to use any of their imports:
scrapy/core/downloader/handlers/http.py F401
scrapy/http/__init__.py F401
# Issues pending a review:
# extras
extras/qps-bench-server.py E501
extras/qpsclient.py E501 E501
# scrapy/commands
scrapy/commands/__init__.py E128 E501
scrapy/commands/check.py E501
scrapy/commands/crawl.py E501
scrapy/commands/edit.py E501
scrapy/commands/fetch.py E401 E501 E128 E731
scrapy/commands/genspider.py E128 E501
scrapy/commands/parse.py E128 E501 E731
scrapy/commands/runspider.py E501
scrapy/commands/settings.py E128
scrapy/commands/shell.py E128 E501
scrapy/commands/startproject.py E127 E501 E128
scrapy/commands/version.py E501 E128
# scrapy/contracts
scrapy/contracts/__init__.py E501 W504
scrapy/contracts/default.py E128
# scrapy/core
scrapy/core/engine.py E501 E128 E127
scrapy/core/scheduler.py E501
scrapy/core/scraper.py E501 E128 W504
scrapy/core/spidermw.py E501 E731 E126
scrapy/core/downloader/__init__.py E501
scrapy/core/downloader/contextfactory.py E501 E128 E126
scrapy/core/downloader/middleware.py E501
scrapy/core/downloader/tls.py E501
scrapy/core/downloader/webclient.py E731 E501 E128 E126
scrapy/core/downloader/handlers/__init__.py E501
scrapy/core/downloader/handlers/ftp.py E501 E128 E127
scrapy/core/downloader/handlers/http10.py E501
scrapy/core/downloader/handlers/http11.py E501
scrapy/core/downloader/handlers/s3.py E501 E128 E126
# scrapy/downloadermiddlewares
scrapy/downloadermiddlewares/ajaxcrawl.py E501
scrapy/downloadermiddlewares/decompression.py E501
scrapy/downloadermiddlewares/defaultheaders.py E501
scrapy/downloadermiddlewares/httpcache.py E501 E126
scrapy/downloadermiddlewares/httpcompression.py E501 E128
scrapy/downloadermiddlewares/httpproxy.py E501
scrapy/downloadermiddlewares/redirect.py E501 W504
scrapy/downloadermiddlewares/retry.py E501 E126
scrapy/downloadermiddlewares/robotstxt.py E501
scrapy/downloadermiddlewares/stats.py E501
# scrapy/extensions
scrapy/extensions/closespider.py E501 E128 E123
scrapy/extensions/corestats.py E501
scrapy/extensions/feedexport.py E128 E501
scrapy/extensions/httpcache.py E128 E501
scrapy/extensions/memdebug.py E501
scrapy/extensions/spiderstate.py E501
scrapy/extensions/telnet.py E501 W504
scrapy/extensions/throttle.py E501
# scrapy/http
scrapy/http/common.py E501
scrapy/http/cookies.py E501
scrapy/http/request/__init__.py E501
scrapy/http/request/form.py E501 E123
scrapy/http/request/json_request.py E501
scrapy/http/response/__init__.py E501 E128
scrapy/http/response/text.py E501 E128 E124
# scrapy/linkextractors
scrapy/linkextractors/__init__.py E731 E501 E402 W504
scrapy/linkextractors/lxmlhtml.py E501 E731
# scrapy/loader
scrapy/loader/__init__.py E501 E128
scrapy/loader/processors.py E501
# scrapy/pipelines
scrapy/pipelines/__init__.py E501
scrapy/pipelines/files.py E116 E501
scrapy/pipelines/images.py E501
scrapy/pipelines/media.py E125 E501
# scrapy/selector
scrapy/selector/__init__.py F403
scrapy/selector/unified.py E501 E111
# scrapy/settings
scrapy/settings/__init__.py E501
scrapy/settings/default_settings.py E501 E114 E116
scrapy/settings/deprecated.py E501
# scrapy/spidermiddlewares
scrapy/spidermiddlewares/httperror.py E501
scrapy/spidermiddlewares/offsite.py E501
scrapy/spidermiddlewares/referer.py E501 E129 W504
scrapy/spidermiddlewares/urllength.py E501
# scrapy/spiders
scrapy/spiders/__init__.py E501 E402
scrapy/spiders/crawl.py E501
scrapy/spiders/feed.py E501
scrapy/spiders/sitemap.py E501
# scrapy/utils
scrapy/utils/asyncio.py E501
scrapy/utils/benchserver.py E501
scrapy/utils/conf.py E402 E501
scrapy/utils/datatypes.py E501
scrapy/utils/decorators.py E501
scrapy/utils/defer.py E501 E128
scrapy/utils/deprecate.py E128 E501 E127
scrapy/utils/gz.py E501 W504
scrapy/utils/http.py F403
scrapy/utils/httpobj.py E501
scrapy/utils/iterators.py E501
scrapy/utils/log.py E128 E501
scrapy/utils/markup.py F403
scrapy/utils/misc.py E501
scrapy/utils/multipart.py F403
scrapy/utils/project.py E501
scrapy/utils/python.py E501
scrapy/utils/reactor.py E501
scrapy/utils/reqser.py E501
scrapy/utils/request.py E127 E501
scrapy/utils/response.py E501 E128
scrapy/utils/signal.py E501 E128
scrapy/utils/sitemap.py E501
scrapy/utils/spider.py E501
scrapy/utils/ssl.py E501
scrapy/utils/test.py E501
scrapy/utils/url.py E501 F403 E128 F405
# scrapy
scrapy/__init__.py E402 E501
scrapy/cmdline.py E501
scrapy/crawler.py E501
scrapy/dupefilters.py E501
scrapy/exceptions.py E501
scrapy/exporters.py E501
scrapy/interfaces.py E501
scrapy/item.py E501 E128
scrapy/link.py E501
scrapy/logformatter.py E501
scrapy/mail.py E402 E128 E501
scrapy/middleware.py E128 E501
scrapy/pqueues.py E501
scrapy/resolver.py E501
scrapy/responsetypes.py E128 E501
scrapy/robotstxt.py E501
scrapy/shell.py E501
scrapy/signalmanager.py E501
scrapy/spiderloader.py F841 E501 E126
scrapy/squeues.py E128
scrapy/statscollectors.py E501
# tests
tests/__init__.py E402 E501
tests/mockserver.py E401 E501 E126 E123
tests/pipelines.py F841
tests/spiders.py E501 E127
tests/test_closespider.py E501 E127
tests/test_command_fetch.py E501
tests/test_command_parse.py E501 E128
tests/test_command_shell.py E501 E128
tests/test_commands.py E128 E501
tests/test_contracts.py E501 E128
tests/test_crawl.py E501 E741
tests/test_crawler.py F841 E501
tests/test_dependencies.py F841 E501
tests/test_downloader_handlers.py E124 E127 E128 E501 E126 E123
tests/test_downloadermiddleware.py E501
tests/test_downloadermiddleware_ajaxcrawlable.py E501
tests/test_downloadermiddleware_cookies.py E731 E741 E501 E128 E126
tests/test_downloadermiddleware_decompression.py E127
tests/test_downloadermiddleware_defaultheaders.py E501
tests/test_downloadermiddleware_downloadtimeout.py E501
tests/test_downloadermiddleware_httpcache.py E501
tests/test_downloadermiddleware_httpcompression.py E501 E126 E123
tests/test_downloadermiddleware_httpproxy.py E501 E128
tests/test_downloadermiddleware_redirect.py E501 E128 E127
tests/test_downloadermiddleware_retry.py E501 E128 E126
tests/test_downloadermiddleware_robotstxt.py E501
tests/test_downloadermiddleware_stats.py E501
tests/test_dupefilters.py E501 E741 E128 E124
tests/test_engine.py E401 E501 E128
tests/test_exporters.py E501 E731 E128 E124
tests/test_extension_telnet.py F841
tests/test_feedexport.py E501 F841
tests/test_http_cookies.py E501
tests/test_http_headers.py E501
tests/test_http_request.py E402 E501 E127 E128 E128 E126 E123
tests/test_http_response.py E501 E128
tests/test_item.py E128 F841
tests/test_link.py E501
tests/test_linkextractors.py E501 E128 E124
tests/test_loader.py E501 E731 E741 E128 E117
tests/test_logformatter.py E128 E501 E122
tests/test_mail.py E128 E501
tests/test_middleware.py E501 E128
tests/test_pipeline_crawl.py E501 E128 E126
tests/test_pipeline_files.py E501
tests/test_pipeline_images.py F841 E501
tests/test_pipeline_media.py E501 E741 E731 E128
tests/test_proxy_connect.py E501 E741
tests/test_request_cb_kwargs.py E501
tests/test_responsetypes.py E501
tests/test_robotstxt_interface.py E501 E501
tests/test_scheduler.py E501 E126 E123
tests/test_selector.py E501 E127
tests/test_spider.py E501
tests/test_spidermiddleware.py E501
tests/test_spidermiddleware_httperror.py E128 E501 E127 E121
tests/test_spidermiddleware_offsite.py E501 E128 E111
tests/test_spidermiddleware_output_chain.py E501
tests/test_spidermiddleware_referer.py E501 F841 E125 E124 E501 E121
tests/test_squeues.py E501 E741
tests/test_utils_asyncio.py E501
tests/test_utils_conf.py E501 E128
tests/test_utils_curl.py E501
tests/test_utils_datatypes.py E402 E501
tests/test_utils_defer.py E501 F841
tests/test_utils_deprecate.py F841 E501
tests/test_utils_http.py E501 E128 W504
tests/test_utils_iterators.py E501 E128 E129
tests/test_utils_log.py E741
tests/test_utils_python.py E501 E731
tests/test_utils_reqser.py E501 E128
tests/test_utils_request.py E501 E128
tests/test_utils_response.py E501
tests/test_utils_signal.py E741 F841 E731
tests/test_utils_sitemap.py E128 E501 E124
tests/test_utils_url.py E501 E127 E125 E501 E126 E123
tests/test_webclient.py E501 E128 E122 E402 E123 E126
tests/test_cmdline/__init__.py E501
tests/test_settings/__init__.py E501 E128
tests/test_spiderloader/__init__.py E128 E501
tests/test_utils_misc/__init__.py E501
filterwarnings=
ignore::DeprecationWarning:twisted.web.test.test_webclient

2
scrapy/VERSION
View File

@ -1 +1 @@
2.0.0
2.5.0

47
scrapy/__init__.py
View File

@ -2,33 +2,11 @@
Scrapy - a web crawling and web scraping framework written for Python
"""
__all__ = ['__version__', 'version_info', 'twisted_version',
'Spider', 'Request', 'FormRequest', 'Selector', 'Item', 'Field']
# Scrapy version
import pkgutil
__version__ = pkgutil.get_data(__package__, 'VERSION').decode('ascii').strip()
version_info = tuple(int(v) if v.isdigit() else v
for v in __version__.split('.'))
del pkgutil
# Check minimum required Python version
import sys
if sys.version_info < (3, 5):
print("Scrapy %s requires Python 3.5" % __version__)
sys.exit(1)
# Ignore noisy twisted deprecation warnings
import warnings
warnings.filterwarnings('ignore', category=DeprecationWarning, module='twisted')
del warnings
# Apply monkey patches to fix issues in external libraries
from scrapy import _monkeypatches
del _monkeypatches
from twisted import version as _txv
twisted_version = (_txv.major, _txv.minor, _txv.micro)
# Declare top-level shortcuts
from scrapy.spiders import Spider
@ -36,4 +14,29 @@ from scrapy.http import Request, FormRequest
from scrapy.selector import Selector
from scrapy.item import Item, Field
__all__ = [
'__version__', 'version_info', 'twisted_version', 'Spider',
'Request', 'FormRequest', 'Selector', 'Item', 'Field',
]
# Scrapy and Twisted versions
__version__ = (pkgutil.get_data(__package__, "VERSION") or b"").decode("ascii").strip()
version_info = tuple(int(v) if v.isdigit() else v for v in __version__.split('.'))
twisted_version = (_txv.major, _txv.minor, _txv.micro)
# Check minimum required Python version
if sys.version_info < (3, 6):
print("Scrapy %s requires Python 3.6+" % __version__)
sys.exit(1)
# Ignore noisy twisted deprecation warnings
warnings.filterwarnings('ignore', category=DeprecationWarning, module='twisted')
del pkgutil
del sys
del warnings

11
scrapy/_monkeypatches.py
View File

@ -1,11 +0,0 @@
import copyreg
# Undo what Twisted's perspective broker adds to pickle register
# to prevent bugs like Twisted#7989 while serializing requests
import twisted.persisted.styles # NOQA
# Remove only entries with twisted serializers for non-twisted types.
for k, v in frozenset(copyreg.dispatch_table.items()):
if not str(getattr(k, '__module__', '')).startswith('twisted') \
and str(getattr(v, '__module__', '')).startswith('twisted'):
copyreg.dispatch_table.pop(k)

31
scrapy/cmdline.py
View File

@ -19,10 +19,12 @@ def _iter_command_classes(module_name):
# scrapy.utils.spider.iter_spider_classes
for module in walk_modules(module_name):
for obj in vars(module).values():
if inspect.isclass(obj) and \
issubclass(obj, ScrapyCommand) and \
obj.__module__ == module.__name__ and \
not obj == ScrapyCommand:
if (
inspect.isclass(obj)
and issubclass(obj, ScrapyCommand)
and obj.__module__ == module.__name__
and not obj == ScrapyCommand
):
yield obj
@ -42,7 +44,7 @@ def _get_commands_from_entry_points(inproject, group='scrapy.commands'):
if inspect.isclass(obj):
cmds[entry_point.name] = obj()
else:
raise Exception("Invalid entry point %s" % entry_point.name)
raise Exception(f"Invalid entry point {entry_point.name}")
return cmds
@ -65,11 +67,11 @@ def _pop_command_name(argv):
def _print_header(settings, inproject):
version = scrapy.__version__
if inproject:
print("Scrapy %s - project: %s\n" % (scrapy.__version__,
settings['BOT_NAME']))
print(f"Scrapy {version} - project: {settings['BOT_NAME']}\n")
else:
print("Scrapy %s - no active project\n" % scrapy.__version__)
print(f"Scrapy {version} - no active project\n")
def _print_commands(settings, inproject):
@ -79,7 +81,7 @@ def _print_commands(settings, inproject):
print("Available commands:")
cmds = _get_commands_dict(settings, inproject)
for cmdname, cmdclass in sorted(cmds.items()):
print(" %-13s %s" % (cmdname, cmdclass.short_desc()))
print(f" {cmdname:<13} {cmdclass.short_desc()}")
if not inproject:
print()
print(" [ more ] More commands available when run from project directory")
@ -89,7 +91,7 @@ def _print_commands(settings, inproject):
def _print_unknown_command(settings, cmdname, inproject):
_print_header(settings, inproject)
print("Unknown command: %s\n" % cmdname)
print(f"Unknown command: {cmdname}\n")
print('Use "scrapy" to see available commands')
@ -131,7 +133,7 @@ def execute(argv=None, settings=None):
sys.exit(2)
cmd = cmds[cmdname]
parser.usage = "scrapy %s %s" % (cmdname, cmd.syntax())
parser.usage = f"scrapy {cmdname} {cmd.syntax()}"
parser.description = cmd.long_desc()
settings.setdict(cmd.default_settings, priority='command')
cmd.settings = settings
@ -153,7 +155,7 @@ def _run_command(cmd, args, opts):
def _run_command_profiled(cmd, args, opts):
if opts.profile:
sys.stderr.write("scrapy: writing cProfile stats to %r\n" % opts.profile)
sys.stderr.write(f"scrapy: writing cProfile stats to {opts.profile!r}\n")
loc = locals()
p = cProfile.Profile()
p.runctx('cmd.run(args, opts)', globals(), loc)
@ -165,6 +167,7 @@ if __name__ == '__main__':
try:
execute()
finally:
# Twisted prints errors in DebugInfo.__del__, but PyPy does not run gc.collect()
# on exit: http://doc.pypy.org/en/latest/cpython_differences.html?highlight=gc.collect#differences-related-to-garbage-collection-strategies
# Twisted prints errors in DebugInfo.__del__, but PyPy does not run gc.collect() on exit:
# http://doc.pypy.org/en/latest/cpython_differences.html
# ?highlight=gc.collect#differences-related-to-garbage-collection-strategies
garbage_collect()

52
scrapy/commands/__init__.py
View File

@ -3,9 +3,11 @@ Base class for Scrapy commands
"""
import os
from optparse import OptionGroup
from typing import Any, Dict
from twisted.python import failure
from scrapy.utils.conf import arglist_to_dict
from scrapy.utils.conf import arglist_to_dict, feed_process_params_from_cli
from scrapy.exceptions import UsageError
@ -15,7 +17,7 @@ class ScrapyCommand:
crawler_process = None
# default settings to be used for this command instead of global defaults
default_settings = {}
default_settings: Dict[str, Any] = {}
exitcode = 0
@ -23,7 +25,8 @@ class ScrapyCommand:
self.settings = None # set in scrapy.cmdline
def set_crawler(self, crawler):
assert not hasattr(self, '_crawler'), "crawler already set"
if hasattr(self, '_crawler'):
raise RuntimeError("crawler already set")
self._crawler = crawler
def syntax(self):
@ -58,17 +61,17 @@ class ScrapyCommand:
"""
group = OptionGroup(parser, "Global Options")
group.add_option("--logfile", metavar="FILE",
help="log file. if omitted stderr will be used")
help="log file. if omitted stderr will be used")
group.add_option("-L", "--loglevel", metavar="LEVEL", default=None,
help="log level (default: %s)" % self.settings['LOG_LEVEL'])
help=f"log level (default: {self.settings['LOG_LEVEL']})")
group.add_option("--nolog", action="store_true",
help="disable logging completely")
help="disable logging completely")
group.add_option("--profile", metavar="FILE", default=None,
help="write python cProfile stats to FILE")
help="write python cProfile stats to FILE")
group.add_option("--pidfile", metavar="FILE",
help="write process ID to FILE")
help="write process ID to FILE")
group.add_option("-s", "--set", action="append", default=[], metavar="NAME=VALUE",
help="set/override setting (may be repeated)")
help="set/override setting (may be repeated)")
group.add_option("--pdb", action="store_true", help="enable pdb on failure")
parser.add_option_group(group)
@ -103,3 +106,34 @@ class ScrapyCommand:
Entry point for running commands
"""
raise NotImplementedError
class BaseRunSpiderCommand(ScrapyCommand):
"""
Common class used to share functionality between the crawl, parse and runspider commands
"""
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
help="set spider argument (may be repeated)")
parser.add_option("-o", "--output", metavar="FILE", action="append",
help="append scraped items to the end of FILE (use - for stdout)")
parser.add_option("-O", "--overwrite-output", metavar="FILE", action="append",
help="dump scraped items into FILE, overwriting any existing file")
parser.add_option("-t", "--output-format", metavar="FORMAT",
help="format to use for dumping items")
def process_options(self, args, opts):
ScrapyCommand.process_options(self, args, opts)
try:
opts.spargs = arglist_to_dict(opts.spargs)
except ValueError:
raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)
if opts.output or opts.overwrite_output:
feeds = feed_process_params_from_cli(
self.settings,
opts.output,
opts.output_format,
opts.overwrite_output,
)
self.settings.set('FEEDS', feeds, priority='cmdline')

2
scrapy/commands/bench.py
View File

@ -50,7 +50,7 @@ class _BenchSpider(scrapy.Spider):
def start_requests(self):
qargs = {'total': self.total, 'show': self.show}
url = '{}?{}'.format(self.baseurl, urlencode(qargs, doseq=1))
url = f'{self.baseurl}?{urlencode(qargs, doseq=True)}'
return [scrapy.Request(url, dont_filter=True)]
def parse(self, response):

38
scrapy/commands/check.py
View File

@ -17,7 +17,7 @@ class TextTestResult(_TextTestResult):
plural = "s" if run != 1 else ""
writeln(self.separator2)
writeln("Ran %d contract%s in %.3fs" % (run, plural, stop - start))
writeln(f"Ran {run} contract{plural} in {stop - start:.3f}s")
writeln()
infos = []
@ -25,14 +25,14 @@ class TextTestResult(_TextTestResult):
write("FAILED")
failed, errored = map(len, (self.failures, self.errors))
if failed:
infos.append("failures=%d" % failed)
infos.append(f"failures={failed}")
if errored:
infos.append("errors=%d" % errored)
infos.append(f"errors={errored}")
else:
write("OK")
if infos:
writeln(" (%s)" % (", ".join(infos),))
writeln(f" ({', '.join(infos)})")
else:
write("\n")
@ -78,19 +78,19 @@ class Command(ScrapyCommand):
elif tested_methods:
self.crawler_process.crawl(spidercls)
# start checks
if opts.list:
for spider, methods in sorted(contract_reqs.items()):
if not methods and not opts.verbose:
continue
print(spider)
for method in sorted(methods):
print(' * %s' % method)
else:
start = time.time()
self.crawler_process.start()
stop = time.time()
# start checks
if opts.list:
for spider, methods in sorted(contract_reqs.items()):
if not methods and not opts.verbose:
continue
print(spider)
for method in sorted(methods):
print(f' * {method}')
else:
start = time.time()
self.crawler_process.start()
stop = time.time()
result.printErrors()
result.printSummary(start, stop)
self.exitcode = int(not result.wasSuccessful())
result.printErrors()
result.printSummary(start, stop)
self.exitcode = int(not result.wasSuccessful())

32
scrapy/commands/crawl.py
View File

@ -1,9 +1,8 @@
from scrapy.commands import ScrapyCommand
from scrapy.utils.conf import arglist_to_dict, feed_process_params_from_cli
from scrapy.commands import BaseRunSpiderCommand
from scrapy.exceptions import UsageError
class Command(ScrapyCommand):
class Command(BaseRunSpiderCommand):
requires_project = True
@ -13,30 +12,11 @@ class Command(ScrapyCommand):
def short_desc(self):
return "Run a spider"
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
help="set spider argument (may be repeated)")
parser.add_option("-o", "--output", metavar="FILE", action="append",
help="dump scraped items into FILE (use - for stdout)")
parser.add_option("-t", "--output-format", metavar="FORMAT",
help="format to use for dumping items with -o")
def process_options(self, args, opts):
ScrapyCommand.process_options(self, args, opts)
try:
opts.spargs = arglist_to_dict(opts.spargs)
except ValueError:
raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)
if opts.output:
feeds = feed_process_params_from_cli(self.settings, opts.output, opts.output_format)
self.settings.set('FEEDS', feeds, priority='cmdline')
def run(self, args, opts):
if len(args) < 1:
raise UsageError()
elif len(args) > 1:
raise UsageError("running 'scrapy crawl' with more than one spider is no longer supported")
raise UsageError("running 'scrapy crawl' with more than one spider is not supported")
spname = args[0]
crawl_defer = self.crawler_process.crawl(spname, **opts.spargs)
@ -46,6 +26,8 @@ class Command(ScrapyCommand):
else:
self.crawler_process.start()
if self.crawler_process.bootstrap_failed or \
(hasattr(self.crawler_process, 'has_exception') and self.crawler_process.has_exception):
if (
self.crawler_process.bootstrap_failed
or hasattr(self.crawler_process, 'has_exception') and self.crawler_process.has_exception
):
self.exitcode = 1

4
scrapy/commands/edit.py
View File

@ -32,8 +32,8 @@ class Command(ScrapyCommand):
try:
spidercls = self.crawler_process.spider_loader.load(args[0])
except KeyError:
return self._err("Spider not found: %s" % args[0])
return self._err(f"Spider not found: {args[0]}")
sfile = sys.modules[spidercls.__module__].__file__
sfile = sfile.replace('.pyc', '.py')
self.exitcode = os.system('%s "%s"' % (editor, sfile))
self.exitcode = os.system(f'{editor} "{sfile}"')

14
scrapy/commands/fetch.py
View File

@ -19,16 +19,18 @@ class Command(ScrapyCommand):
return "Fetch a URL using the Scrapy downloader"
def long_desc(self):
return "Fetch a URL using the Scrapy downloader and print its content " \
"to stdout. You may want to use --nolog to disable logging"
return (
"Fetch a URL using the Scrapy downloader and print its content"
" to stdout. You may want to use --nolog to disable logging"
)
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("--spider", dest="spider", help="use this spider")
parser.add_option("--headers", dest="headers", action="store_true",
help="print response HTTP headers instead of body")
parser.add_option("--no-redirect", dest="no_redirect", action="store_true",
default=False, help="do not handle HTTP 3xx status codes and print response as-is")
parser.add_option("--no-redirect", dest="no_redirect", action="store_true", default=False,
help="do not handle HTTP 3xx status codes and print response as-is")
def _print_headers(self, headers, prefix):
for key, values in headers.items():
@ -49,8 +51,8 @@ class Command(ScrapyCommand):
def run(self, args, opts):
if len(args) != 1 or not is_url(args[0]):
raise UsageError()
cb = lambda x: self._print_response(x, opts)
request = Request(args[0], callback=cb, dont_filter=True)
request = Request(args[0], callback=self._print_response,
cb_kwargs={"opts": opts}, dont_filter=True)
# by default, let the framework handle redirects,
# i.e. command handles all codes expect 3xx
if not opts.no_redirect:

77
scrapy/commands/genspider.py
View File

@ -36,15 +36,15 @@ class Command(ScrapyCommand):
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("-l", "--list", dest="list", action="store_true",
help="List available templates")
help="List available templates")
parser.add_option("-e", "--edit", dest="edit", action="store_true",
help="Edit spider after creating it")
help="Edit spider after creating it")
parser.add_option("-d", "--dump", dest="dump", metavar="TEMPLATE",
help="Dump template to standard output")
help="Dump template to standard output")
parser.add_option("-t", "--template", dest="template", default="basic",
help="Uses a custom template.")
help="Uses a custom template.")
parser.add_option("--force", dest="force", action="store_true",
help="If the spider already exists, overwrite it with the template")
help="If the spider already exists, overwrite it with the template")
def run(self, args, opts):
if opts.list:
@ -66,31 +66,25 @@ class Command(ScrapyCommand):
print("Cannot create a spider with the same name as your project")
return
try:
spidercls = self.crawler_process.spider_loader.load(name)
except KeyError:
pass
else:
# if spider already exists and not --force then halt
if not opts.force:
print("Spider %r already exists in module:" % name)
print(" %s" % spidercls.__module__)
return
if not opts.force and self._spider_exists(name):
return
template_file = self._find_template(opts.template)
if template_file:
self._genspider(module, name, domain, opts.template, template_file)
if opts.edit:
self.exitcode = os.system('scrapy edit "%s"' % name)
self.exitcode = os.system(f'scrapy edit "{name}"')
def _genspider(self, module, name, domain, template_name, template_file):
"""Generate the spider module, based on the given template"""
capitalized_module = ''.join(s.capitalize() for s in module.split('_'))
tvars = {
'project_name': self.settings.get('BOT_NAME'),
'ProjectName': string_camelcase(self.settings.get('BOT_NAME')),
'module': module,
'name': name,
'domain': domain,
'classname': '%sSpider' % ''.join(s.capitalize() for s in module.split('_'))
'classname': f'{capitalized_module}Spider'
}
if self.settings.get('NEWSPIDER_MODULE'):
spiders_module = import_module(self.settings['NEWSPIDER_MODULE'])
@ -98,29 +92,58 @@ class Command(ScrapyCommand):
else:
spiders_module = None
spiders_dir = "."
spider_file = "%s.py" % join(spiders_dir, module)
spider_file = f"{join(spiders_dir, module)}.py"
shutil.copyfile(template_file, spider_file)
render_templatefile(spider_file, **tvars)
print("Created spider %r using template %r "
% (name, template_name), end=('' if spiders_module else '\n'))
print(f"Created spider {name!r} using template {template_name!r} ",
end=('' if spiders_module else '\n'))
if spiders_module:
print("in module:\n %s.%s" % (spiders_module.__name__, module))
print(f"in module:\n {spiders_module.__name__}.{module}")
def _find_template(self, template):
template_file = join(self.templates_dir, '%s.tmpl' % template)
template_file = join(self.templates_dir, f'{template}.tmpl')
if exists(template_file):
return template_file
print("Unable to find template: %s\n" % template)
print(f"Unable to find template: {template}\n")
print('Use "scrapy genspider --list" to see all available templates.')
def _list_templates(self):
print("Available templates:")
for filename in sorted(os.listdir(self.templates_dir)):
if filename.endswith('.tmpl'):
print(" %s" % splitext(filename)[0])
print(f" {splitext(filename)[0]}")
def _spider_exists(self, name):
if not self.settings.get('NEWSPIDER_MODULE'):
# if run as a standalone command and file with same filename already exists
if exists(name + ".py"):
print(f"{abspath(name + '.py')} already exists")
return True
return False
try:
spidercls = self.crawler_process.spider_loader.load(name)
except KeyError:
pass
else:
# if spider with same name exists
print(f"Spider {name!r} already exists in module:")
print(f" {spidercls.__module__}")
return True
# a file with the same name exists in the target directory
spiders_module = import_module(self.settings['NEWSPIDER_MODULE'])
spiders_dir = dirname(spiders_module.__file__)
spiders_dir_abs = abspath(spiders_dir)
if exists(join(spiders_dir_abs, name + ".py")):
print(f"{join(spiders_dir_abs, (name + '.py'))} already exists")
return True
return False
@property
def templates_dir(self):
_templates_base_dir = self.settings['TEMPLATES_DIR'] or \
join(scrapy.__path__[0], 'templates')
return join(_templates_base_dir, 'spiders')
return join(
self.settings['TEMPLATES_DIR'] or join(scrapy.__path__[0], 'templates'),
'spiders'
)

67
scrapy/commands/parse.py
View File

@ -1,26 +1,26 @@
import json
import logging
from typing import Dict
from itemadapter import is_item, ItemAdapter
from w3lib.url import is_url
from scrapy.commands import ScrapyCommand
from scrapy.commands import BaseRunSpiderCommand
from scrapy.http import Request
from scrapy.item import BaseItem
from scrapy.utils import display
from scrapy.utils.conf import arglist_to_dict
from scrapy.utils.spider import iterate_spider_output, spidercls_for_request
from scrapy.exceptions import UsageError
logger = logging.getLogger(__name__)
class Command(ScrapyCommand):
class Command(BaseRunSpiderCommand):
requires_project = True
spider = None
items = {}
requests = {}
items: Dict[int, list] = {}
requests: Dict[int, list] = {}
first_response = None
@ -31,31 +31,29 @@ class Command(ScrapyCommand):
return "Parse URL (using its spider) and print the results"
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
BaseRunSpiderCommand.add_options(self, parser)
parser.add_option("--spider", dest="spider", default=None,
help="use this spider without looking for one")
parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
help="set spider argument (may be repeated)")
help="use this spider without looking for one")
parser.add_option("--pipelines", action="store_true",
help="process items through pipelines")
help="process items through pipelines")
parser.add_option("--nolinks", dest="nolinks", action="store_true",
help="don't show links to follow (extracted requests)")
help="don't show links to follow (extracted requests)")
parser.add_option("--noitems", dest="noitems", action="store_true",
help="don't show scraped items")
help="don't show scraped items")
parser.add_option("--nocolour", dest="nocolour", action="store_true",
help="avoid using pygments to colorize the output")
help="avoid using pygments to colorize the output")
parser.add_option("-r", "--rules", dest="rules", action="store_true",
help="use CrawlSpider rules to discover the callback")
help="use CrawlSpider rules to discover the callback")
parser.add_option("-c", "--callback", dest="callback",
help="use this callback for parsing, instead looking for a callback")
help="use this callback for parsing, instead looking for a callback")
parser.add_option("-m", "--meta", dest="meta",
help="inject extra meta into the Request, it must be a valid raw json string")
help="inject extra meta into the Request, it must be a valid raw json string")
parser.add_option("--cbkwargs", dest="cbkwargs",
help="inject extra callback kwargs into the Request, it must be a valid raw json string")
help="inject extra callback kwargs into the Request, it must be a valid raw json string")
parser.add_option("-d", "--depth", dest="depth", type="int", default=1,
help="maximum depth for parsing requests [default: %default]")
help="maximum depth for parsing requests [default: %default]")
parser.add_option("-v", "--verbose", dest="verbose", action="store_true",
help="print each depth level one by one")
help="print each depth level one by one")
@property
def max_level(self):
@ -81,7 +79,7 @@ class Command(ScrapyCommand):
items = self.items.get(lvl, [])
print("# Scraped Items ", "-" * 60)
display.pprint([dict(x) for x in items], colorize=colour)
display.pprint([ItemAdapter(x).asdict() for x in items], colorize=colour)
def print_requests(self, lvl=None, colour=True):
if lvl is None:
@ -100,13 +98,13 @@ class Command(ScrapyCommand):
if opts.verbose:
for level in range(1, self.max_level + 1):
print('\n>>> DEPTH LEVEL: %s <<<' % level)
print(f'\n>>> DEPTH LEVEL: {level} <<<')
if not opts.noitems:
self.print_items(level, colour)
if not opts.nolinks:
self.print_requests(level, colour)
else:
print('\n>>> STATUS DEPTH LEVEL %s <<<' % self.max_level)
print(f'\n>>> STATUS DEPTH LEVEL {self.max_level} <<<')
if not opts.noitems:
self.print_items(colour=colour)
if not opts.nolinks:
@ -117,7 +115,7 @@ class Command(ScrapyCommand):
items, requests = [], []
for x in iterate_spider_output(callback(response, **cb_kwargs)):
if isinstance(x, (BaseItem, dict)):
if is_item(x):
items.append(x)
elif isinstance(x, Request):
requests.append(x)
@ -146,9 +144,8 @@ class Command(ScrapyCommand):
if not self.spidercls:
logger.error('Unable to find spider for: %(url)s', {'url': url})
# Request requires callback argument as callable or None, not string
request = Request(url, None)
_start_requests = lambda s: [self.prepare_request(s, request, opts)]
def _start_requests(spider):
yield self.prepare_request(spider, Request(url), opts)
self.spidercls.start_requests = _start_requests
def start_parsing(self, url, opts):
@ -201,12 +198,15 @@ class Command(ScrapyCommand):
self.add_items(depth, items)
self.add_requests(depth, requests)
scraped_data = items if opts.output else []
if depth < opts.depth:
for req in requests:
req.meta['_depth'] = depth + 1
req.meta['_callback'] = req.callback
req.callback = callback
return requests
scraped_data += requests
return scraped_data
# update request meta if any extra meta was passed through the --meta/-m opts.
if opts.meta:
@ -222,18 +222,11 @@ class Command(ScrapyCommand):
return request
def process_options(self, args, opts):
ScrapyCommand.process_options(self, args, opts)
BaseRunSpiderCommand.process_options(self, args, opts)
self.process_spider_arguments(opts)
self.process_request_meta(opts)
self.process_request_cb_kwargs(opts)
def process_spider_arguments(self, opts):
try:
opts.spargs = arglist_to_dict(opts.spargs)
except ValueError:
raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)
def process_request_meta(self, opts):
if opts.meta:
try:

34
scrapy/commands/runspider.py
View File

@ -3,17 +3,16 @@ import os
from importlib import import_module
from scrapy.utils.spider import iter_spider_classes
from scrapy.commands import ScrapyCommand
from scrapy.exceptions import UsageError
from scrapy.utils.conf import arglist_to_dict, feed_process_params_from_cli
from scrapy.commands import BaseRunSpiderCommand
def _import_file(filepath):
abspath = os.path.abspath(filepath)
dirname, file = os.path.split(abspath)
fname, fext = os.path.splitext(file)
if fext != '.py':
raise ValueError("Not a Python source file: %s" % abspath)
if fext not in ('.py', '.pyw'):
raise ValueError(f"Not a Python source file: {abspath}")
if dirname:
sys.path = [dirname] + sys.path
try:
@ -24,7 +23,7 @@ def _import_file(filepath):
return module
class Command(ScrapyCommand):
class Command(BaseRunSpiderCommand):
requires_project = False
default_settings = {'SPIDER_LOADER_WARN_ONLY': True}
@ -38,38 +37,19 @@ class Command(ScrapyCommand):
def long_desc(self):
return "Run the spider defined in the given file"
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("-a", dest="spargs", action="append", default=[], metavar="NAME=VALUE",
help="set spider argument (may be repeated)")
parser.add_option("-o", "--output", metavar="FILE", action="append",
help="dump scraped items into FILE (use - for stdout)")
parser.add_option("-t", "--output-format", metavar="FORMAT",
help="format to use for dumping items with -o")
def process_options(self, args, opts):
ScrapyCommand.process_options(self, args, opts)
try:
opts.spargs = arglist_to_dict(opts.spargs)
except ValueError:
raise UsageError("Invalid -a value, use -a NAME=VALUE", print_help=False)
if opts.output:
feeds = feed_process_params_from_cli(self.settings, opts.output, opts.output_format)
self.settings.set('FEEDS', feeds, priority='cmdline')
def run(self, args, opts):
if len(args) != 1:
raise UsageError()
filename = args[0]
if not os.path.exists(filename):
raise UsageError("File not found: %s\n" % filename)
raise UsageError(f"File not found: {filename}\n")
try:
module = _import_file(filename)
except (ImportError, ValueError) as e:
raise UsageError("Unable to load %r: %s\n" % (filename, e))
raise UsageError(f"Unable to load {filename!r}: {e}\n")
spclasses = list(iter_spider_classes(module))
if not spclasses:
raise UsageError("No spider found in file: %s\n" % filename)
raise UsageError(f"No spider found in file: {filename}\n")
spidercls = spclasses.pop()
self.crawler_process.crawl(spidercls, **opts.spargs)

10
scrapy/commands/settings.py
View File

@ -19,15 +19,15 @@ class Command(ScrapyCommand):
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("--get", dest="get", metavar="SETTING",
help="print raw setting value")
help="print raw setting value")
parser.add_option("--getbool", dest="getbool", metavar="SETTING",
help="print setting value, interpreted as a boolean")
help="print setting value, interpreted as a boolean")
parser.add_option("--getint", dest="getint", metavar="SETTING",
help="print setting value, interpreted as an integer")
help="print setting value, interpreted as an integer")
parser.add_option("--getfloat", dest="getfloat", metavar="SETTING",
help="print setting value, interpreted as a float")
help="print setting value, interpreted as a float")
parser.add_option("--getlist", dest="getlist", metavar="SETTING",
help="print setting value, interpreted as a list")
help="print setting value, interpreted as a list")
def run(self, args, opts):
settings = self.crawler_process.settings

8
scrapy/commands/shell.py
View File

@ -34,11 +34,11 @@ class Command(ScrapyCommand):
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("-c", dest="code",
help="evaluate the code in the shell, print the result and exit")
help="evaluate the code in the shell, print the result and exit")
parser.add_option("--spider", dest="spider",
help="use this spider")
parser.add_option("--no-redirect", dest="no_redirect", action="store_true",
default=False, help="do not handle HTTP 3xx status codes and print response as-is")
help="use this spider")
parser.add_option("--no-redirect", dest="no_redirect", action="store_true", default=False,
help="do not handle HTTP 3xx status codes and print response as-is")
def update_vars(self, vars):
"""You can use this function to update the Scrapy objects that will be

36
scrapy/commands/startproject.py
View File

@ -4,6 +4,7 @@ import string
from importlib import import_module
from os.path import join, exists, abspath
from shutil import ignore_patterns, move, copy2, copystat
from stat import S_IWUSR as OWNER_WRITE_PERMISSION
import scrapy
from scrapy.commands import ScrapyCommand
@ -19,7 +20,12 @@ TEMPLATES_TO_RENDER = (
('${project_name}', 'middlewares.py.tmpl'),
)
IGNORE = ignore_patterns('*.pyc', '.svn')
IGNORE = ignore_patterns('*.pyc', '__pycache__', '.svn')
def _make_writable(path):
current_permissions = os.stat(path).st_mode
os.chmod(path, current_permissions | OWNER_WRITE_PERMISSION)
class Command(ScrapyCommand):
@ -46,7 +52,7 @@ class Command(ScrapyCommand):
print('Error: Project names must begin with a letter and contain'
' only\nletters, numbers and underscores')
elif _module_exists(project_name):
print('Error: Module %r already exists' % project_name)
print(f'Error: Module {project_name!r} already exists')
else:
return True
return False
@ -77,7 +83,10 @@ class Command(ScrapyCommand):
self._copytree(srcname, dstname)
else:
copy2(srcname, dstname)
_make_writable(dstname)
copystat(src, dst)
_make_writable(dst)
def run(self, args, opts):
if len(args) not in (1, 2):
@ -91,7 +100,7 @@ class Command(ScrapyCommand):
if exists(join(project_dir, 'scrapy.cfg')):
self.exitcode = 1
print('Error: scrapy.cfg already exists in %s' % abspath(project_dir))
print(f'Error: scrapy.cfg already exists in {abspath(project_dir)}')
return
if not self._is_valid_name(project_name):
@ -102,19 +111,18 @@ class Command(ScrapyCommand):
move(join(project_dir, 'module'), join(project_dir, project_name))
for paths in TEMPLATES_TO_RENDER:
path = join(*paths)
tplfile = join(project_dir,
string.Template(path).substitute(project_name=project_name))
render_templatefile(tplfile, project_name=project_name,
ProjectName=string_camelcase(project_name))
print("New Scrapy project '%s', using template directory '%s', "
"created in:" % (project_name, self.templates_dir))
print(" %s\n" % abspath(project_dir))
tplfile = join(project_dir, string.Template(path).substitute(project_name=project_name))
render_templatefile(tplfile, project_name=project_name, ProjectName=string_camelcase(project_name))
print(f"New Scrapy project '{project_name}', using template directory "
f"'{self.templates_dir}', created in:")
print(f" {abspath(project_dir)}\n")
print("You can start your first spider with:")
print(" cd %s" % project_dir)
print(f" cd {project_dir}")
print(" scrapy genspider example example.com")
@property
def templates_dir(self):
_templates_base_dir = self.settings['TEMPLATES_DIR'] or \
join(scrapy.__path__[0], 'templates')
return join(_templates_base_dir, 'project')
return join(
self.settings['TEMPLATES_DIR'] or join(scrapy.__path__[0], 'templates'),
'project'
)

7
scrapy/commands/version.py
View File

@ -17,14 +17,13 @@ class Command(ScrapyCommand):
def add_options(self, parser):
ScrapyCommand.add_options(self, parser)
parser.add_option("--verbose", "-v", dest="verbose", action="store_true",
help="also display twisted/python/platform info (useful for bug reports)")
help="also display twisted/python/platform info (useful for bug reports)")
def run(self, args, opts):
if opts.verbose:
versions = scrapy_components_versions()
width = max(len(n) for (n, _) in versions)
patt = "%-{}s : %s".format(width)
for name, version in versions:
print(patt % (name, version))
print(f"{name:<{width}} : {version}")
else:
print("Scrapy %s" % scrapy.__version__)
print(f"Scrapy {scrapy.__version__}")

5
scrapy/commands/view.py
View File

@ -8,11 +8,10 @@ class Command(fetch.Command):
return "Open URL in browser, as seen by Scrapy"
def long_desc(self):
return "Fetch a URL using the Scrapy downloader and show its " \
"contents in a browser"
return "Fetch a URL using the Scrapy downloader and show its contents in a browser"
def add_options(self, parser):
super(Command, self).add_options(parser)
super().add_options(parser)
parser.remove_option("--headers")
def _print_response(self, response, opts):

135
scrapy/contracts/__init__.py
View File

@ -1,26 +1,87 @@
import sys
import re
import sys
from functools import wraps
from inspect import getmembers
from typing import Dict
from unittest import TestCase
from scrapy.http import Request
from scrapy.utils.spider import iterate_spider_output
from scrapy.utils.python import get_spec
from scrapy.utils.spider import iterate_spider_output
class Contract:
""" Abstract class for contracts """
request_cls = None
def __init__(self, method, *args):
self.testcase_pre = _create_testcase(method, f'@{self.name} pre-hook')
self.testcase_post = _create_testcase(method, f'@{self.name} post-hook')
self.args = args
def add_pre_hook(self, request, results):
if hasattr(self, 'pre_process'):
cb = request.callback
@wraps(cb)
def wrapper(response, **cb_kwargs):
try:
results.startTest(self.testcase_pre)
self.pre_process(response)
results.stopTest(self.testcase_pre)
except AssertionError:
results.addFailure(self.testcase_pre, sys.exc_info())
except Exception:
results.addError(self.testcase_pre, sys.exc_info())
else:
results.addSuccess(self.testcase_pre)
finally:
return list(iterate_spider_output(cb(response, **cb_kwargs)))
request.callback = wrapper
return request
def add_post_hook(self, request, results):
if hasattr(self, 'post_process'):
cb = request.callback
@wraps(cb)
def wrapper(response, **cb_kwargs):
output = list(iterate_spider_output(cb(response, **cb_kwargs)))
try:
results.startTest(self.testcase_post)
self.post_process(output)
results.stopTest(self.testcase_post)
except AssertionError:
results.addFailure(self.testcase_post, sys.exc_info())
except Exception:
results.addError(self.testcase_post, sys.exc_info())
else:
results.addSuccess(self.testcase_post)
finally:
return output
request.callback = wrapper
return request
def adjust_request_args(self, args):
return args
class ContractsManager:
contracts = {}
contracts: Dict[str, Contract] = {}
def __init__(self, contracts):
for contract in contracts:
self.contracts[contract.name] = contract
def tested_methods_from_spidercls(self, spidercls):
is_method = re.compile(r"^\s*@", re.MULTILINE).search
methods = []
for key, value in getmembers(spidercls):
if (callable(value) and value.__doc__ and
re.search(r'^\s*@', value.__doc__, re.MULTILINE)):
if callable(value) and value.__doc__ and is_method(value.__doc__):
methods.append(key)
return methods
@ -107,73 +168,13 @@ class ContractsManager:
request.errback = eb_wrapper
class Contract:
""" Abstract class for contracts """
request_cls = None
def __init__(self, method, *args):
self.testcase_pre = _create_testcase(method, '@%s pre-hook' % self.name)
self.testcase_post = _create_testcase(method, '@%s post-hook' % self.name)
self.args = args
def add_pre_hook(self, request, results):
if hasattr(self, 'pre_process'):
cb = request.callback
@wraps(cb)
def wrapper(response, **cb_kwargs):
try:
results.startTest(self.testcase_pre)
self.pre_process(response)
results.stopTest(self.testcase_pre)
except AssertionError:
results.addFailure(self.testcase_pre, sys.exc_info())
except Exception:
results.addError(self.testcase_pre, sys.exc_info())
else:
results.addSuccess(self.testcase_pre)
finally:
return list(iterate_spider_output(cb(response, **cb_kwargs)))
request.callback = wrapper
return request
def add_post_hook(self, request, results):
if hasattr(self, 'post_process'):
cb = request.callback
@wraps(cb)
def wrapper(response, **cb_kwargs):
output = list(iterate_spider_output(cb(response, **cb_kwargs)))
try:
results.startTest(self.testcase_post)
self.post_process(output)
results.stopTest(self.testcase_post)
except AssertionError:
results.addFailure(self.testcase_post, sys.exc_info())
except Exception:
results.addError(self.testcase_post, sys.exc_info())
else:
results.addSuccess(self.testcase_post)
finally:
return output
request.callback = wrapper
return request
def adjust_request_args(self, args):
return args
def _create_testcase(method, desc):
spider = method.__self__.name
class ContractTestCase(TestCase):
def __str__(_self):
return "[%s] %s (%s)" % (spider, method.__name__, desc)
return f"[{spider}] {method.__name__} ({desc})"
name = '%s_%s' % (spider, method.__name__)
name = f'{spider}_{method.__name__}'
setattr(ContractTestCase, name, lambda x: x)
return ContractTestCase(name)

40
scrapy/contracts/default.py
View File

@ -1,10 +1,10 @@
import json
from scrapy.item import BaseItem
from scrapy.http import Request
from scrapy.exceptions import ContractFail
from itemadapter import is_item, ItemAdapter
from scrapy.contracts import Contract
from scrapy.exceptions import ContractFail
from scrapy.http import Request
# contracts
@ -48,19 +48,22 @@ class ReturnsContract(Contract):
"""
name = 'returns'
objects = {
'request': Request,
'requests': Request,
'item': (BaseItem, dict),
'items': (BaseItem, dict),
object_type_verifiers = {
'request': lambda x: isinstance(x, Request),
'requests': lambda x: isinstance(x, Request),
'item': is_item,
'items': is_item,
}
def __init__(self, *args, **kwargs):
super(ReturnsContract, self).__init__(*args, **kwargs)
super().__init__(*args, **kwargs)
assert len(self.args) in [1, 2, 3]
if len(self.args) not in [1, 2, 3]:
raise ValueError(
f"Incorrect argument quantity: expected 1, 2 or 3, got {len(self.args)}"
)
self.obj_name = self.args[0] or None
self.obj_type = self.objects[self.obj_name]
self.obj_type_verifier = self.object_type_verifiers[self.obj_name]
try:
self.min_bound = int(self.args[1])
@ -75,7 +78,7 @@ class ReturnsContract(Contract):
def post_process(self, output):
occurrences = 0
for x in output:
if isinstance(x, self.obj_type):
if self.obj_type_verifier(x):
occurrences += 1
assertion = (self.min_bound <= occurrences <= self.max_bound)
@ -84,10 +87,9 @@ class ReturnsContract(Contract):
if self.min_bound == self.max_bound:
expected = self.min_bound
else:
expected = '%s..%s' % (self.min_bound, self.max_bound)
expected = f'{self.min_bound}..{self.max_bound}'
raise ContractFail("Returned %s %s, expected %s" %
(occurrences, self.obj_name, expected))
raise ContractFail(f"Returned {occurrences} {self.obj_name}, expected {expected}")
class ScrapesContract(Contract):
@ -99,8 +101,8 @@ class ScrapesContract(Contract):
def post_process(self, output):
for x in output:
if isinstance(x, (BaseItem, dict)):
missing = [arg for arg in self.args if arg not in x]
if is_item(x):
missing = [arg for arg in self.args if arg not in ItemAdapter(x)]
if missing:
raise ContractFail(
"Missing fields: %s" % ", ".join(missing))
missing_fields = ", ".join(missing)
raise ContractFail(f"Missing fields: {missing_fields}")

18
scrapy/core/downloader/__init__.py
View File

@ -41,17 +41,17 @@ class Slot:
def __repr__(self):
cls_name = self.__class__.__name__
return "%s(concurrency=%r, delay=%0.2f, randomize_delay=%r)" % (
cls_name, self.concurrency, self.delay, self.randomize_delay)
return (f"{cls_name}(concurrency={self.concurrency!r}, "
f"delay={self.delay:.2f}, "
f"randomize_delay={self.randomize_delay!r})")
def __str__(self):
return (
"<downloader.Slot concurrency=%r delay=%0.2f randomize_delay=%r "
"len(active)=%d len(queue)=%d len(transferring)=%d lastseen=%s>" % (
self.concurrency, self.delay, self.randomize_delay,
len(self.active), len(self.queue), len(self.transferring),
datetime.fromtimestamp(self.lastseen).isoformat()
)
f"<downloader.Slot concurrency={self.concurrency!r} "
f"delay={self.delay:.2f} randomize_delay={self.randomize_delay!r} "
f"len(active)={len(self.active)} len(queue)={len(self.queue)} "
f"len(transferring)={len(self.transferring)} "
f"lastseen={datetime.fromtimestamp(self.lastseen).isoformat()}>"
)
@ -173,7 +173,7 @@ class Downloader:
return response
dfd.addCallback(_downloaded)
# 3. After response arrives, remove the request from transferring
# 3. After response arrives, remove the request from transferring
# state to free up the transferring slot so it can be used by the
# following requests (perhaps those which came from the downloader
# middleware itself)

80
scrapy/core/downloader/contextfactory.py
View File

@ -1,10 +1,15 @@
import warnings
from OpenSSL import SSL
from twisted.internet._sslverify import _setAcceptableProtocols
from twisted.internet.ssl import optionsForClientTLS, CertificateOptions, platformTrust, AcceptableCiphers
from twisted.web.client import BrowserLikePolicyForHTTPS
from twisted.web.iweb import IPolicyForHTTPS
from zope.interface.declarations import implementer
from zope.interface.verify import verifyObject
from scrapy.core.downloader.tls import ScrapyClientTLSOptions, DEFAULT_CIPHERS
from scrapy.core.downloader.tls import DEFAULT_CIPHERS, openssl_methods, ScrapyClientTLSOptions
from scrapy.utils.misc import create_instance, load_object
@implementer(IPolicyForHTTPS)
@ -20,7 +25,7 @@ class ScrapyClientContextFactory(BrowserLikePolicyForHTTPS):
"""
def __init__(self, method=SSL.SSLv23_METHOD, tls_verbose_logging=False, tls_ciphers=None, *args, **kwargs):
super(ScrapyClientContextFactory, self).__init__(*args, **kwargs)
super().__init__(*args, **kwargs)
self._ssl_method = method
self.tls_verbose_logging = tls_verbose_logging
if tls_ciphers:
@ -45,12 +50,13 @@ class ScrapyClientContextFactory(BrowserLikePolicyForHTTPS):
# (https://github.com/scrapy/scrapy/issues/1429#issuecomment-131782133)
#
# * getattr() for `_ssl_method` attribute for context factories
# not calling super(..., self).__init__
return CertificateOptions(verify=False,
method=getattr(self, 'method',
getattr(self, '_ssl_method', None)),
fixBrokenPeers=True,
acceptableCiphers=self.tls_ciphers)
# not calling super().__init__
return CertificateOptions(
verify=False,
method=getattr(self, 'method', getattr(self, '_ssl_method', None)),
fixBrokenPeers=True,
acceptableCiphers=self.tls_ciphers,
)
# kept for old-style HTTP/1.0 downloader context twisted calls,
# e.g. connectSSL()
@ -80,14 +86,60 @@ class BrowserLikeContextFactory(ScrapyClientContextFactory):
The default OpenSSL method is ``TLS_METHOD`` (also called
``SSLv23_METHOD``) which allows TLS protocol negotiation.
"""
def creatorForNetloc(self, hostname, port):
def creatorForNetloc(self, hostname, port):
# trustRoot set to platformTrust() will use the platform's root CAs.
#
# This means that a website like https://www.cacert.org will be rejected
# by default, since CAcert.org CA certificate is seldom shipped.
return optionsForClientTLS(hostname.decode("ascii"),
trustRoot=platformTrust(),
extraCertificateOptions={
'method': self._ssl_method,
})
return optionsForClientTLS(
hostname=hostname.decode("ascii"),
trustRoot=platformTrust(),
extraCertificateOptions={'method': self._ssl_method},
)
@implementer(IPolicyForHTTPS)
class AcceptableProtocolsContextFactory:
"""Context factory to used to override the acceptable protocols
to set up the [OpenSSL.SSL.Context] for doing NPN and/or ALPN
negotiation.
"""
def __init__(self, context_factory, acceptable_protocols):
verifyObject(IPolicyForHTTPS, context_factory)
self._wrapped_context_factory = context_factory
self._acceptable_protocols = acceptable_protocols
def creatorForNetloc(self, hostname, port):
options = self._wrapped_context_factory.creatorForNetloc(hostname, port)
_setAcceptableProtocols(options._ctx, self._acceptable_protocols)
return options
def load_context_factory_from_settings(settings, crawler):
ssl_method = openssl_methods[settings.get('DOWNLOADER_CLIENT_TLS_METHOD')]
context_factory_cls = load_object(settings['DOWNLOADER_CLIENTCONTEXTFACTORY'])
# try method-aware context factory
try:
context_factory = create_instance(
objcls=context_factory_cls,
settings=settings,
crawler=crawler,
method=ssl_method,
)
except TypeError:
# use context factory defaults
context_factory = create_instance(
objcls=context_factory_cls,
settings=settings,
crawler=crawler,
)
msg = """
'%s' does not accept `method` argument (type OpenSSL.SSL method,\
e.g. OpenSSL.SSL.SSLv23_METHOD) and/or `tls_verbose_logging` argument and/or `tls_ciphers` argument.\
Please upgrade your context factory class to handle them or ignore them.""" % (
settings['DOWNLOADER_CLIENTCONTEXTFACTORY'],)
warnings.warn(msg)
return context_factory

3
scrapy/core/downloader/handlers/__init__.py
View File

@ -71,8 +71,7 @@ class DownloadHandlers:
scheme = urlparse_cached(request).scheme
handler = self._get_handler(scheme)
if not handler:
raise NotSupported("Unsupported URL scheme '%s': %s" %
(scheme, self._notconfigured[scheme]))
raise NotSupported(f"Unsupported URL scheme '{scheme}': {self._notconfigured[scheme]}")
return handler.download_request(request, spider)
@defer.inlineCallbacks

18
scrapy/core/downloader/handlers/ftp.py
View File

@ -86,19 +86,19 @@ class FTPDownloadHandler:
password = request.meta.get("ftp_password", self.default_password)
passive_mode = 1 if bool(request.meta.get("ftp_passive",
self.passive_mode)) else 0
creator = ClientCreator(reactor, FTPClient, user, password,
passive=passive_mode)
return creator.connectTCP(parsed_url.hostname, parsed_url.port or 21).addCallback(self.gotClient,
request, unquote(parsed_url.path))
creator = ClientCreator(reactor, FTPClient, user, password, passive=passive_mode)
dfd = creator.connectTCP(parsed_url.hostname, parsed_url.port or 21)
return dfd.addCallback(self.gotClient, request, unquote(parsed_url.path))
def gotClient(self, client, request, filepath):
self.client = client
protocol = ReceivedDataProtocol(request.meta.get("ftp_local_filename"))
return client.retrieveFile(filepath, protocol)\
.addCallbacks(callback=self._build_response,
callbackArgs=(request, protocol),
errback=self._failed,
errbackArgs=(request,))
return client.retrieveFile(filepath, protocol).addCallbacks(
callback=self._build_response,
callbackArgs=(request, protocol),
errback=self._failed,
errbackArgs=(request,),
)
def _build_response(self, result, request, protocol):
self.result = result

211
scrapy/core/downloader/handlers/http11.py
View File

@ -1,5 +1,6 @@
"""Download handlers for http and https schemes"""
import ipaddress
import logging
import re
import warnings
@ -11,18 +12,19 @@ from urllib.parse import urldefrag
from twisted.internet import defer, protocol, ssl
from twisted.internet.endpoints import TCP4ClientEndpoint
from twisted.internet.error import TimeoutError
from twisted.python.failure import Failure
from twisted.web.client import Agent, HTTPConnectionPool, ResponseDone, ResponseFailed, URI
from twisted.web.http import _DataLoss, PotentialDataLoss
from twisted.web.http_headers import Headers as TxHeaders
from twisted.web.iweb import IBodyProducer, UNKNOWN_LENGTH
from zope.interface import implementer
from scrapy.core.downloader.tls import openssl_methods
from scrapy import signals
from scrapy.core.downloader.contextfactory import load_context_factory_from_settings
from scrapy.core.downloader.webclient import _parse
from scrapy.exceptions import ScrapyDeprecationWarning
from scrapy.exceptions import ScrapyDeprecationWarning, StopDownload
from scrapy.http import Headers
from scrapy.responsetypes import responsetypes
from scrapy.utils.misc import create_instance, load_object
from scrapy.utils.python import to_bytes, to_unicode
@ -33,34 +35,14 @@ class HTTP11DownloadHandler:
lazy = False
def __init__(self, settings, crawler=None):
self._crawler = crawler
from twisted.internet import reactor
self._pool = HTTPConnectionPool(reactor, persistent=True)
self._pool.maxPersistentPerHost = settings.getint('CONCURRENT_REQUESTS_PER_DOMAIN')
self._pool._factory.noisy = False
self._sslMethod = openssl_methods[settings.get('DOWNLOADER_CLIENT_TLS_METHOD')]
self._contextFactoryClass = load_object(settings['DOWNLOADER_CLIENTCONTEXTFACTORY'])
# try method-aware context factory
try:
self._contextFactory = create_instance(
objcls=self._contextFactoryClass,
settings=settings,
crawler=crawler,
method=self._sslMethod,
)
except TypeError:
# use context factory defaults
self._contextFactory = create_instance(
objcls=self._contextFactoryClass,
settings=settings,
crawler=crawler,
)
msg = """
'%s' does not accept `method` argument (type OpenSSL.SSL method,\
e.g. OpenSSL.SSL.SSLv23_METHOD) and/or `tls_verbose_logging` argument and/or `tls_ciphers` argument.\
Please upgrade your context factory class to handle them or ignore them.""" % (
settings['DOWNLOADER_CLIENTCONTEXTFACTORY'],)
warnings.warn(msg)
self._contextFactory = load_context_factory_from_settings(settings, crawler)
self._default_maxsize = settings.getint('DOWNLOAD_MAXSIZE')
self._default_warnsize = settings.getint('DOWNLOAD_WARNSIZE')
self._fail_on_dataloss = settings.getbool('DOWNLOAD_FAIL_ON_DATALOSS')
@ -78,6 +60,7 @@ class HTTP11DownloadHandler:
maxsize=getattr(spider, 'download_maxsize', self._default_maxsize),
warnsize=getattr(spider, 'download_warnsize', self._default_warnsize),
fail_on_dataloss=self._fail_on_dataloss,
crawler=self._crawler,
)
return agent.download_request(request)
@ -115,12 +98,13 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
with this endpoint comes from the pool and a CONNECT has already been issued
for it.
"""
_responseMatcher = re.compile(br'HTTP/1\.. (?P<status>\d{3})(?P<reason>.{,32})')
_truncatedLength = 1000
_responseAnswer = r'HTTP/1\.. (?P<status>\d{3})(?P<reason>.{,' + str(_truncatedLength) + r'})'
_responseMatcher = re.compile(_responseAnswer.encode())
def __init__(self, reactor, host, port, proxyConf, contextFactory, timeout=30, bindAddress=None):
proxyHost, proxyPort, self._proxyAuthHeader = proxyConf
super(TunnelingTCP4ClientEndpoint, self).__init__(reactor, proxyHost, proxyPort, timeout, bindAddress)
super().__init__(reactor, proxyHost, proxyPort, timeout, bindAddress)
self._tunnelReadyDeferred = defer.Deferred()
self._tunneledHost = host
self._tunneledPort = port
@ -161,10 +145,11 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
extra = {'status': int(respm.group('status')),
'reason': respm.group('reason').strip()}
else:
extra = rcvd_bytes[:32]
extra = rcvd_bytes[:self._truncatedLength]
self._tunnelReadyDeferred.errback(
TunnelError('Could not open CONNECT tunnel with proxy %s:%s [%r]' % (
self._host, self._port, extra)))
TunnelError('Could not open CONNECT tunnel with proxy '
f'{self._host}:{self._port} [{extra!r}]')
)
def connectFailed(self, reason):
"""Propagates the errback to the appropriate deferred."""
@ -172,7 +157,7 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
def connect(self, protocolFactory):
self._protocolFactory = protocolFactory
connectDeferred = super(TunnelingTCP4ClientEndpoint, self).connect(protocolFactory)
connectDeferred = super().connect(protocolFactory)
connectDeferred.addCallback(self.requestTunnel)
connectDeferred.addErrback(self.connectFailed)
return self._tunnelReadyDeferred
@ -209,7 +194,7 @@ class TunnelingAgent(Agent):
def __init__(self, reactor, proxyConf, contextFactory=None,
connectTimeout=None, bindAddress=None, pool=None):
super(TunnelingAgent, self).__init__(reactor, contextFactory, connectTimeout, bindAddress, pool)
super().__init__(reactor, contextFactory, connectTimeout, bindAddress, pool)
self._proxyConf = proxyConf
self._contextFactory = contextFactory
@ -229,7 +214,7 @@ class TunnelingAgent(Agent):
# otherwise, same remote host connection request could reuse
# a cached tunneled connection to a different proxy
key = key + self._proxyConf
return super(TunnelingAgent, self)._requestWithEndpoint(
return super()._requestWithEndpoint(
key=key,
endpoint=endpoint,
method=method,
@ -243,7 +228,7 @@ class TunnelingAgent(Agent):
class ScrapyProxyAgent(Agent):
def __init__(self, reactor, proxyURI, connectTimeout=None, bindAddress=None, pool=None):
super(ScrapyProxyAgent, self).__init__(
super().__init__(
reactor=reactor,
connectTimeout=connectTimeout,
bindAddress=bindAddress,
@ -275,7 +260,7 @@ class ScrapyAgent:
_TunnelingAgent = TunnelingAgent
def __init__(self, contextFactory=None, connectTimeout=10, bindAddress=None, pool=None,
maxsize=0, warnsize=0, fail_on_dataloss=True):
maxsize=0, warnsize=0, fail_on_dataloss=True, crawler=None):
self._contextFactory = contextFactory
self._connectTimeout = connectTimeout
self._bindAddress = bindAddress
@ -284,6 +269,7 @@ class ScrapyAgent:
self._warnsize = warnsize
self._fail_on_dataloss = fail_on_dataloss
self._txresponse = None
self._crawler = crawler
def _get_agent(self, request, timeout):
from twisted.internet import reactor
@ -295,11 +281,14 @@ class ScrapyAgent:
proxyHost = to_unicode(proxyHost)
omitConnectTunnel = b'noconnect' in proxyParams
if omitConnectTunnel:
warnings.warn("Using HTTPS proxies in the noconnect mode is deprecated. "
"If you use Crawlera, it doesn't require this mode anymore, "
"so you should update scrapy-crawlera to 1.3.0+ "
"and remove '?noconnect' from the Crawlera URL.",
ScrapyDeprecationWarning)
warnings.warn(
"Using HTTPS proxies in the noconnect mode is deprecated. "
"If you use Zyte Smart Proxy Manager, it doesn't require "
"this mode anymore, so you should update scrapy-crawlera "
"to scrapy-zyte-smartproxy and remove '?noconnect' "
"from the Zyte Smart Proxy Manager URL.",
ScrapyDeprecationWarning,
)
if scheme == b'https' and not omitConnectTunnel:
proxyAuth = request.headers.get(b'Proxy-Authorization', None)
proxyConf = (proxyHost, proxyPort, proxyAuth)
@ -364,16 +353,53 @@ class ScrapyAgent:
if self._txresponse:
self._txresponse._transport.stopProducing()
raise TimeoutError("Getting %s took longer than %s seconds." % (url, timeout))
raise TimeoutError(f"Getting {url} took longer than {timeout} seconds.")
def _cb_latency(self, result, request, start_time):
request.meta['download_latency'] = time() - start_time
return result
@staticmethod
def _headers_from_twisted_response(response):
headers = Headers()
if response.length != UNKNOWN_LENGTH:
headers[b'Content-Length'] = str(response.length).encode()
headers.update(response.headers.getAllRawHeaders())
return headers
def _cb_bodyready(self, txresponse, request):
headers_received_result = self._crawler.signals.send_catch_log(
signal=signals.headers_received,
headers=self._headers_from_twisted_response(txresponse),
body_length=txresponse.length,
request=request,
spider=self._crawler.spider,
)
for handler, result in headers_received_result:
if isinstance(result, Failure) and isinstance(result.value, StopDownload):
logger.debug("Download stopped for %(request)s from signal handler %(handler)s",
{"request": request, "handler": handler.__qualname__})
txresponse._transport.stopProducing()
with suppress(AttributeError):
txresponse._transport._producer.loseConnection()
return {
"txresponse": txresponse,
"body": b"",
"flags": ["download_stopped"],
"certificate": None,
"ip_address": None,
"failure": result if result.value.fail else None,
}
# deliverBody hangs for responses without body
if txresponse.length == 0:
return txresponse, b'', None, None
return {
"txresponse": txresponse,
"body": b"",
"flags": None,
"certificate": None,
"ip_address": None,
}
maxsize = request.meta.get('download_maxsize', self._maxsize)
warnsize = request.meta.get('download_warnsize', self._warnsize)
@ -381,13 +407,14 @@ class ScrapyAgent:
fail_on_dataloss = request.meta.get('download_fail_on_dataloss', self._fail_on_dataloss)
if maxsize and expected_size > maxsize:
error_msg = ("Cancelling download of %(url)s: expected response "
"size (%(size)s) larger than download max size (%(maxsize)s).")
error_args = {'url': request.url, 'size': expected_size, 'maxsize': maxsize}
warning_msg = ("Cancelling download of %(url)s: expected response "
"size (%(size)s) larger than download max size (%(maxsize)s).")
warning_args = {'url': request.url, 'size': expected_size, 'maxsize': maxsize}
logger.warning(warning_msg, warning_args)
logger.error(error_msg, error_args)
txresponse._transport._producer.loseConnection()
raise defer.CancelledError(error_msg % error_args)
raise defer.CancelledError(warning_msg % warning_args)
if warnsize and expected_size > warnsize:
logger.warning("Expected response size (%(size)s) larger than "
@ -400,7 +427,15 @@ class ScrapyAgent:
d = defer.Deferred(_cancel)
txresponse.deliverBody(
_ResponseReader(d, txresponse, request, maxsize, warnsize, fail_on_dataloss)
_ResponseReader(
finished=d,
txresponse=txresponse,
request=request,
maxsize=maxsize,
warnsize=warnsize,
fail_on_dataloss=fail_on_dataloss,
crawler=self._crawler,
)
)
# save response for timeouts
@ -409,12 +444,27 @@ class ScrapyAgent:
return d
def _cb_bodydone(self, result, request, url):
txresponse, body, flags, certificate = result
status = int(txresponse.code)
headers = Headers(txresponse.headers.getAllRawHeaders())
respcls = responsetypes.from_args(headers=headers, url=url, body=body)
return respcls(url=url, status=status, headers=headers, body=body,
flags=flags, certificate=certificate)
headers = self._headers_from_twisted_response(result["txresponse"])
respcls = responsetypes.from_args(headers=headers, url=url, body=result["body"])
try:
version = result["txresponse"].version
protocol = f"{to_unicode(version[0])}/{version[1]}.{version[2]}"
except (AttributeError, TypeError, IndexError):
protocol = None
response = respcls(
url=url,
status=int(result["txresponse"].code),
headers=headers,
body=result["body"],
flags=result["flags"],
certificate=result["certificate"],
ip_address=result["ip_address"],
protocol=protocol,
)
if result.get("failure"):
result["failure"].value.response = response
return result["failure"]
return response
@implementer(IBodyProducer)
@ -437,7 +487,7 @@ class _RequestBodyProducer:
class _ResponseReader(protocol.Protocol):
def __init__(self, finished, txresponse, request, maxsize, warnsize, fail_on_dataloss):
def __init__(self, finished, txresponse, request, maxsize, warnsize, fail_on_dataloss, crawler):
self._finished = finished
self._txresponse = txresponse
self._request = request
@ -449,12 +499,27 @@ class _ResponseReader(protocol.Protocol):
self._reached_warnsize = False
self._bytes_received = 0
self._certificate = None
self._ip_address = None
self._crawler = crawler
def _finish_response(self, flags=None, failure=None):
self._finished.callback({
"txresponse": self._txresponse,
"body": self._bodybuf.getvalue(),
"flags": flags,
"certificate": self._certificate,
"ip_address": self._ip_address,
"failure": failure,
})
def connectionMade(self):
if self._certificate is None:
with suppress(AttributeError):
self._certificate = ssl.Certificate(self.transport._producer.getPeerCertificate())
if self._ip_address is None:
self._ip_address = ipaddress.ip_address(self.transport._producer.getPeer().host)
def dataReceived(self, bodyBytes):
# This maybe called several times after cancel was called with buffered data.
if self._finished.called:
@ -463,12 +528,27 @@ class _ResponseReader(protocol.Protocol):
self._bodybuf.write(bodyBytes)
self._bytes_received += len(bodyBytes)
bytes_received_result = self._crawler.signals.send_catch_log(
signal=signals.bytes_received,
data=bodyBytes,
request=self._request,
spider=self._crawler.spider,
)
for handler, result in bytes_received_result:
if isinstance(result, Failure) and isinstance(result.value, StopDownload):
logger.debug("Download stopped for %(request)s from signal handler %(handler)s",
{"request": self._request, "handler": handler.__qualname__})
self.transport.stopProducing()
self.transport._producer.loseConnection()
failure = result if result.value.fail else None
self._finish_response(flags=["download_stopped"], failure=failure)
if self._maxsize and self._bytes_received > self._maxsize:
logger.error("Received (%(bytes)s) bytes larger than download "
"max size (%(maxsize)s) in request %(request)s.",
{'bytes': self._bytes_received,
'maxsize': self._maxsize,
'request': self._request})
logger.warning("Received (%(bytes)s) bytes larger than download "
"max size (%(maxsize)s) in request %(request)s.",
{'bytes': self._bytes_received,
'maxsize': self._maxsize,
'request': self._request})
# Clear buffer earlier to avoid keeping data in memory for a long time.
self._bodybuf.truncate(0)
self._finished.cancel()
@ -484,18 +564,17 @@ class _ResponseReader(protocol.Protocol):
if self._finished.called:
return
body = self._bodybuf.getvalue()
if reason.check(ResponseDone):
self._finished.callback((self._txresponse, body, None, self._certificate))
self._finish_response()
return
if reason.check(PotentialDataLoss):
self._finished.callback((self._txresponse, body, ['partial'], self._certificate))
self._finish_response(flags=["partial"])
return
if reason.check(ResponseFailed) and any(r.check(_DataLoss) for r in reason.value.reasons):
if not self._fail_on_dataloss:
self._finished.callback((self._txresponse, body, ['dataloss'], self._certificate))
self._finish_response(flags=["dataloss"])
return
elif not self._fail_on_dataloss_warned:

129
scrapy/core/downloader/handlers/http2.py Normal file
View File

@ -0,0 +1,129 @@
import warnings
from time import time
from typing import Optional, Type, TypeVar
from urllib.parse import urldefrag
from twisted.internet.base import DelayedCall
from twisted.internet.defer import Deferred
from twisted.internet.error import TimeoutError
from twisted.web.client import URI
from scrapy.core.downloader.contextfactory import load_context_factory_from_settings
from scrapy.core.downloader.webclient import _parse
from scrapy.core.http2.agent import H2Agent, H2ConnectionPool, ScrapyProxyH2Agent
from scrapy.crawler import Crawler
from scrapy.http import Request, Response
from scrapy.settings import Settings
from scrapy.spiders import Spider
from scrapy.utils.python import to_bytes
H2DownloadHandlerOrSubclass = TypeVar("H2DownloadHandlerOrSubclass", bound="H2DownloadHandler")
class H2DownloadHandler:
def __init__(self, settings: Settings, crawler: Optional[Crawler] = None):
self._crawler = crawler
from twisted.internet import reactor
self._pool = H2ConnectionPool(reactor, settings)
self._context_factory = load_context_factory_from_settings(settings, crawler)
@classmethod
def from_crawler(cls: Type[H2DownloadHandlerOrSubclass], crawler: Crawler) -> H2DownloadHandlerOrSubclass:
return cls(crawler.settings, crawler)
def download_request(self, request: Request, spider: Spider) -> Deferred:
agent = ScrapyH2Agent(
context_factory=self._context_factory,
pool=self._pool,
crawler=self._crawler,
)
return agent.download_request(request, spider)
def close(self) -> None:
self._pool.close_connections()
class ScrapyH2Agent:
_Agent = H2Agent
_ProxyAgent = ScrapyProxyH2Agent
def __init__(
self, context_factory,
pool: H2ConnectionPool,
connect_timeout: int = 10,
bind_address: Optional[bytes] = None,
crawler: Optional[Crawler] = None,
) -> None:
self._context_factory = context_factory
self._connect_timeout = connect_timeout
self._bind_address = bind_address
self._pool = pool
self._crawler = crawler
def _get_agent(self, request: Request, timeout: Optional[float]) -> H2Agent:
from twisted.internet import reactor
bind_address = request.meta.get('bindaddress') or self._bind_address
proxy = request.meta.get('proxy')
if proxy:
_, _, proxy_host, proxy_port, proxy_params = _parse(proxy)
scheme = _parse(request.url)[0]
proxy_host = proxy_host.decode()
omit_connect_tunnel = b'noconnect' in proxy_params
if omit_connect_tunnel:
warnings.warn(
"Using HTTPS proxies in the noconnect mode is not "
"supported by the downloader handler. If you use Zyte "
"Smart Proxy Manager, it doesn't require this mode "
"anymore, so you should update scrapy-crawlera to "
"scrapy-zyte-smartproxy and remove '?noconnect' from the "
"Zyte Smart Proxy Manager URL."
)
if scheme == b'https' and not omit_connect_tunnel:
# ToDo
raise NotImplementedError('Tunneling via CONNECT method using HTTP/2.0 is not yet supported')
return self._ProxyAgent(
reactor=reactor,
context_factory=self._context_factory,
proxy_uri=URI.fromBytes(to_bytes(proxy, encoding='ascii')),
connect_timeout=timeout,
bind_address=bind_address,
pool=self._pool,
)
return self._Agent(
reactor=reactor,
context_factory=self._context_factory,
connect_timeout=timeout,
bind_address=bind_address,
pool=self._pool,
)
def download_request(self, request: Request, spider: Spider) -> Deferred:
from twisted.internet import reactor
timeout = request.meta.get('download_timeout') or self._connect_timeout
agent = self._get_agent(request, timeout)
start_time = time()
d = agent.request(request, spider)
d.addCallback(self._cb_latency, request, start_time)
timeout_cl = reactor.callLater(timeout, d.cancel)
d.addBoth(self._cb_timeout, request, timeout, timeout_cl)
return d
@staticmethod
def _cb_latency(response: Response, request: Request, start_time: float) -> Response:
request.meta['download_latency'] = time() - start_time
return response
@staticmethod
def _cb_timeout(response: Response, request: Request, timeout: float, timeout_cl: DelayedCall) -> Response:
if timeout_cl.active():
timeout_cl.cancel()
return response
url = urldefrag(request.url)[0]
raise TimeoutError(f"Getting {url} took longer than {timeout} seconds.")

72
scrapy/core/downloader/handlers/s3.py
View File

@ -2,41 +2,20 @@ from urllib.parse import unquote
from scrapy.core.downloader.handlers.http import HTTPDownloadHandler
from scrapy.exceptions import NotConfigured
from scrapy.utils.boto import is_botocore
from scrapy.utils.boto import is_botocore_available
from scrapy.utils.httpobj import urlparse_cached
from scrapy.utils.misc import create_instance
def _get_boto_connection():
from boto.s3.connection import S3Connection
class _v19_S3Connection(S3Connection):
"""A dummy S3Connection wrapper that doesn't do any synchronous download"""
def _mexe(self, method, bucket, key, headers, *args, **kwargs):
return headers
class _v20_S3Connection(S3Connection):
"""A dummy S3Connection wrapper that doesn't do any synchronous download"""
def _mexe(self, http_request, *args, **kwargs):
http_request.authorize(connection=self)
return http_request.headers
try:
import boto.auth # noqa: F401
except ImportError:
_S3Connection = _v19_S3Connection
else:
_S3Connection = _v20_S3Connection
return _S3Connection
class S3DownloadHandler:
def __init__(self, settings, *,
crawler=None,
aws_access_key_id=None, aws_secret_access_key=None,
httpdownloadhandler=HTTPDownloadHandler, **kw):
if not is_botocore_available():
raise NotConfigured('missing botocore library')
if not aws_access_key_id:
aws_access_key_id = settings['AWS_ACCESS_KEY_ID']
if not aws_secret_access_key:
@ -51,23 +30,15 @@ class S3DownloadHandler:
self.anon = kw.get('anon')
self._signer = None
if is_botocore():
import botocore.auth
import botocore.credentials
kw.pop('anon', None)
if kw:
raise TypeError('Unexpected keyword arguments: %s' % kw)
if not self.anon:
SignerCls = botocore.auth.AUTH_TYPE_MAPS['s3']
self._signer = SignerCls(botocore.credentials.Credentials(
aws_access_key_id, aws_secret_access_key))
else:
_S3Connection = _get_boto_connection()
try:
self.conn = _S3Connection(
aws_access_key_id, aws_secret_access_key, **kw)
except Exception as ex:
raise NotConfigured(str(ex))
import botocore.auth
import botocore.credentials
kw.pop('anon', None)
if kw:
raise TypeError(f'Unexpected keyword arguments: {kw}')
if not self.anon:
SignerCls = botocore.auth.AUTH_TYPE_MAPS['s3']
self._signer = SignerCls(botocore.credentials.Credentials(
aws_access_key_id, aws_secret_access_key))
_http_handler = create_instance(
objcls=httpdownloadhandler,
@ -85,14 +56,14 @@ class S3DownloadHandler:
scheme = 'https' if request.meta.get('is_secure') else 'http'
bucket = p.hostname
path = p.path + '?' + p.query if p.query else p.path
url = '%s://%s.s3.amazonaws.com%s' % (scheme, bucket, path)
url = f'{scheme}://{bucket}.s3.amazonaws.com{path}'
if self.anon:
request = request.replace(url=url)
elif self._signer is not None:
import botocore.awsrequest
awsrequest = botocore.awsrequest.AWSRequest(
method=request.method,
url='%s://s3.amazonaws.com/%s%s' % (scheme, bucket, path),
url=f'{scheme}://s3.amazonaws.com/{bucket}{path}',
headers=request.headers.to_unicode_dict(),
data=request.body)
self._signer.add_auth(awsrequest)
@ -100,11 +71,12 @@ class S3DownloadHandler:
url=url, headers=awsrequest.headers.items())
else:
signed_headers = self.conn.make_request(
method=request.method,
bucket=bucket,
key=unquote(p.path),
query_args=unquote(p.query),
headers=request.headers,
data=request.body)
method=request.method,
bucket=bucket,
key=unquote(p.path),
query_args=unquote(p.query),
headers=request.headers,
data=request.body,
)
request = request.replace(url=url, headers=signed_headers)
return self._download_http(request, spider)

47
scrapy/core/downloader/middleware.py
View File

@ -3,8 +3,12 @@ Downloader Middleware manager
See documentation in docs/topics/downloader-middleware.rst
"""
from twisted.internet import defer
from typing import Callable, Union
from twisted.internet import defer
from twisted.python.failure import Failure
from scrapy import Spider
from scrapy.exceptions import _InvalidOutput
from scrapy.http import Request, Response
from scrapy.middleware import MiddlewareManager
@ -29,50 +33,51 @@ class DownloaderMiddlewareManager(MiddlewareManager):
if hasattr(mw, 'process_exception'):
self.methods['process_exception'].appendleft(mw.process_exception)
def download(self, download_func, request, spider):
def download(self, download_func: Callable, request: Request, spider: Spider):
@defer.inlineCallbacks
def process_request(request):
def process_request(request: Request):
for method in self.methods['process_request']:
response = yield deferred_from_coro(method(request=request, spider=spider))
if response is not None and not isinstance(response, (Response, Request)):
raise _InvalidOutput(
"Middleware %s.process_request must return None, Response or Request, got %s"
% (method.__self__.__class__.__name__, response.__class__.__name__)
f"Middleware {method.__qualname__} must return None, Response or "
f"Request, got {response.__class__.__name__}"
)
if response:
defer.returnValue(response)
defer.returnValue((yield download_func(request=request, spider=spider)))
return response
return (yield download_func(request=request, spider=spider))
@defer.inlineCallbacks
def process_response(response):
assert response is not None, 'Received None in process_response'
if isinstance(response, Request):
defer.returnValue(response)
def process_response(response: Union[Response, Request]):
if response is None:
raise TypeError("Received None in process_response")
elif isinstance(response, Request):
return response
for method in self.methods['process_response']:
response = yield deferred_from_coro(method(request=request, response=response, spider=spider))
if not isinstance(response, (Response, Request)):
raise _InvalidOutput(
"Middleware %s.process_response must return Response or Request, got %s"
% (method.__self__.__class__.__name__, type(response))
f"Middleware {method.__qualname__} must return Response or Request, "
f"got {type(response)}"
)
if isinstance(response, Request):
defer.returnValue(response)
defer.returnValue(response)
return response
return response
@defer.inlineCallbacks
def process_exception(_failure):
exception = _failure.value
def process_exception(failure: Failure):
exception = failure.value
for method in self.methods['process_exception']:
response = yield deferred_from_coro(method(request=request, exception=exception, spider=spider))
if response is not None and not isinstance(response, (Response, Request)):
raise _InvalidOutput(
"Middleware %s.process_exception must return None, Response or Request, got %s"
% (method.__self__.__class__.__name__, type(response))
f"Middleware {method.__qualname__} must return None, Response or "
f"Request, got {type(response)}"
)
if response:
defer.returnValue(response)
defer.returnValue(_failure)
return response
return failure
deferred = mustbe_deferred(process_request, request)
deferred.addErrback(process_exception)

29
scrapy/core/downloader/tls.py
View File

@ -5,7 +5,6 @@ from service_identity.exceptions import CertificateError
from twisted.internet._sslverify import ClientTLSOptions, verifyHostname, VerificationError
from twisted.internet.ssl import AcceptableCiphers
from scrapy import twisted_version
from scrapy.utils.ssl import x509name_to_string, get_temp_key_info
@ -28,13 +27,6 @@ openssl_methods = {
}
if twisted_version < (17, 0, 0):
from twisted.internet._sslverify import _maybeSetHostNameIndication as set_tlsext_host_name
else:
def set_tlsext_host_name(connection, hostNameBytes):
connection.set_tlsext_host_name(hostNameBytes)
class ScrapyClientTLSOptions(ClientTLSOptions):
"""
SSL Client connection creator ignoring certificate verification errors
@ -47,26 +39,19 @@ class ScrapyClientTLSOptions(ClientTLSOptions):
"""
def __init__(self, hostname, ctx, verbose_logging=False):
super(ScrapyClientTLSOptions, self).__init__(hostname, ctx)
super().__init__(hostname, ctx)
self.verbose_logging = verbose_logging
def _identityVerifyingInfoCallback(self, connection, where, ret):
if where & SSL.SSL_CB_HANDSHAKE_START:
set_tlsext_host_name(connection, self._hostnameBytes)
connection.set_tlsext_host_name(self._hostnameBytes)
elif where & SSL.SSL_CB_HANDSHAKE_DONE:
if self.verbose_logging:
if hasattr(connection, 'get_cipher_name'): # requires pyOPenSSL 0.15
if hasattr(connection, 'get_protocol_version_name'): # requires pyOPenSSL 16.0.0
logger.debug('SSL connection to %s using protocol %s, cipher %s',
self._hostnameASCII,
connection.get_protocol_version_name(),
connection.get_cipher_name(),
)
else:
logger.debug('SSL connection to %s using cipher %s',
self._hostnameASCII,
connection.get_cipher_name(),
)
logger.debug('SSL connection to %s using protocol %s, cipher %s',
self._hostnameASCII,
connection.get_protocol_version_name(),
connection.get_cipher_name(),
)
server_cert = connection.get_peer_certificate()
logger.debug('SSL connection certificate: issuer "%s", subject "%s"',
x509name_to_string(server_cert.get_issuer()),

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