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Merge branch 'master' into feat-685

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Adrián Chaves 2020-02-10 19:45:09 +01:00 committed by GitHub
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18
.bandit.yml Normal file
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skips:
- B101
- B105
- B301
- B303
- B306
- B307
- B311
- B320
- B321
- B402 # https://github.com/scrapy/scrapy/issues/4180
- B403
- B404
- B406
- B410
- B503
- B603
- B605

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.bumpversion.cfg
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@ -1,5 +1,5 @@
[bumpversion]
current_version = 1.6.0
current_version = 1.8.0
commit = True
tag = True
tag_name = {new_version}

3
.coveragerc
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@ -3,6 +3,3 @@ branch = true
include = scrapy/*
omit =
tests/*
scrapy/xlib/*
scrapy/conf.py
scrapy/log.py

41
.github/ISSUE_TEMPLATE/bug_report.md vendored Normal file
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@ -0,0 +1,41 @@
---
name: Bug report
about: Report a problem to help us improve
---
<!--
Thanks for taking an interest in Scrapy!
If you have a question that starts with "How to...", please see the Scrapy Community page: https://scrapy.org/community/.
The GitHub issue tracker's purpose is to deal with bug reports and feature requests for the project itself.
Keep in mind that by filing an issue, you are expected to comply with Scrapy's Code of Conduct, including treating everyone with respect: https://github.com/scrapy/scrapy/blob/master/CODE_OF_CONDUCT.md
The following is a suggested template to structure your issue, you can find more guidelines at https://doc.scrapy.org/en/latest/contributing.html#reporting-bugs
-->
### Description
[Description of the issue]
### Steps to Reproduce
1. [First Step]
2. [Second Step]
3. [and so on...]
**Expected behavior:** [What you expect to happen]
**Actual behavior:** [What actually happens]
**Reproduces how often:** [What percentage of the time does it reproduce?]
### Versions
Please paste here the output of executing `scrapy version --verbose` in the command line.
### Additional context
Any additional information, configuration, data or output from commands that might be necessary to reproduce or understand the issue. Please try not to include screenshots of code or the command line, paste the contents as text instead. You can use [GitHub Flavored Markdown](https://help.github.com/en/articles/creating-and-highlighting-code-blocks) to make the text look better.

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.github/ISSUE_TEMPLATE/feature_request.md vendored Normal file
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@ -0,0 +1,33 @@
---
name: Feature request
about: Suggest an idea for an enhancement or new feature
---
<!--
Thanks for taking an interest in Scrapy!
If you have a question that starts with "How to...", please see the Scrapy Community page: https://scrapy.org/community/.
The GitHub issue tracker's purpose is to deal with bug reports and feature requests for the project itself.
Keep in mind that by filing an issue, you are expected to comply with Scrapy's Code of Conduct, including treating everyone with respect: https://github.com/scrapy/scrapy/blob/master/CODE_OF_CONDUCT.md
The following is a suggested template to structure your pull request, you can find more guidelines at https://doc.scrapy.org/en/latest/contributing.html#writing-patches and https://doc.scrapy.org/en/latest/contributing.html#submitting-patches
-->
## Summary
One paragraph explanation of the feature.
## Motivation
Why are we doing this? What use cases does it support? What is the expected outcome?
## Describe alternatives you've considered
A clear and concise description of the alternative solutions you've considered. Be sure to explain why Scrapy's existing customizability isn't suitable for this feature.
## Additional context
Any additional information about the feature request here.

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.readthedocs.yml Normal file
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@ -0,0 +1,9 @@
version: 2
sphinx:
configuration: docs/conf.py
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
install:
- requirements: docs/requirements.txt

53
.travis.yml
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@ -1,4 +1,5 @@
language: python
dist: xenial
branches:
only:
- master
@ -6,35 +7,31 @@ branches:
- /^\d\.\d+\.\d+(rc\d+|\.dev\d+)?$/
matrix:
include:
- python: 2.7
env: TOXENV=py27
- python: 2.7
env: TOXENV=jessie
- python: 2.7
env: TOXENV=pypy
- python: 2.7
env: TOXENV=pypy3
- python: 3.4
env: TOXENV=py34
- python: 3.5
env: TOXENV=py35
- python: 3.6
env: TOXENV=py36
- python: 3.7
env: TOXENV=py37
dist: xenial
sudo: true
- python: 3.6
env: TOXENV=docs
- env: TOXENV=security
python: 3.8
- env: TOXENV=flake8
python: 3.8
- env: TOXENV=pypy3
- env: TOXENV=py35
python: 3.5
- env: TOXENV=pinned
python: 3.5
- env: TOXENV=py35-asyncio
python: 3.5.2
- env: TOXENV=py36
python: 3.6
- env: TOXENV=py37
python: 3.7
- env: TOXENV=py38
python: 3.8
- env: TOXENV=extra-deps
python: 3.8
- env: TOXENV=py38-asyncio
python: 3.8
- env: TOXENV=docs
python: 3.7 # Keep in sync with .readthedocs.yml
install:
- |
if [ "$TOXENV" = "pypy" ]; then
export PYPY_VERSION="pypy-6.0.0-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/pypy" "$HOME/virtualenvs/$PYPY_VERSION"
source "$HOME/virtualenvs/$PYPY_VERSION/bin/activate"
fi
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"
@ -65,4 +62,4 @@ deploy:
on:
tags: true
repo: scrapy/scrapy
condition: "$TOXENV == py27 && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$"
condition: "$TOXENV == py37 && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$"

2
CODE_OF_CONDUCT.md
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@ -68,7 +68,7 @@ members of the project's leadership.
## Attribution
This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
available at [http://contributor-covenant.org/version/1/4][version]
available at [http://contributor-covenant.org/version/1/4][version].
[homepage]: http://contributor-covenant.org
[version]: http://contributor-covenant.org/version/1/4/

20
README.rst
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@ -34,13 +34,13 @@ 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.
For more information including a list of features check the Scrapy homepage at:
https://scrapy.org
Check the Scrapy homepage at https://scrapy.org for more information,
including a list of features.
Requirements
============
* Python 2.7 or Python 3.4+
* Python 3.5+
* Works on Linux, Windows, Mac OSX, BSD
Install
@ -50,8 +50,8 @@ The quick way::
pip install scrapy
For more details see the install section in the documentation:
https://docs.scrapy.org/en/latest/intro/install.html
See the install section in the documentation at
https://docs.scrapy.org/en/latest/intro/install.html for more details.
Documentation
=============
@ -62,17 +62,17 @@ directory.
Releases
========
You can find release notes at https://docs.scrapy.org/en/latest/news.html
You can check https://docs.scrapy.org/en/latest/news.html for the release notes.
Community (blog, twitter, mail list, IRC)
=========================================
See https://scrapy.org/community/
See https://scrapy.org/community/ for details.
Contributing
============
See https://docs.scrapy.org/en/master/contributing.html
See https://docs.scrapy.org/en/master/contributing.html for details.
Code of Conduct
---------------
@ -86,9 +86,9 @@ Please report unacceptable behavior to opensource@scrapinghub.com.
Companies using Scrapy
======================
See https://scrapy.org/companies/
See https://scrapy.org/companies/ for a list.
Commercial Support
==================
See https://scrapy.org/support/
See https://scrapy.org/support/ for details.

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appveyor.yml
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@ -12,7 +12,8 @@ branches:
install:
- "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
- "SET TOX_TESTENV_PASSENV=HOME USERPROFILE HOMEPATH HOMEDRIVE"
- "SET PYTHONPATH=%APPVEYOR_BUILD_FOLDER%"
- "SET TOX_TESTENV_PASSENV=HOME HOMEDRIVE HOMEPATH PYTHONPATH USERPROFILE"
- "pip install -U tox"
build: false

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artwork/README.rst
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@ -1,5 +1,4 @@
:orphan:
==============
Scrapy artwork
==============

52
conftest.py
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@ -1,35 +1,51 @@
import glob
import six
from pathlib import Path
import pytest
from twisted import version as twisted_version
def _py_files(folder):
return glob.glob(folder + "/*.py") + glob.glob(folder + "/*/*.py")
return (str(p) for p in Path(folder).rglob('*.py'))
collect_ignore = [
# deprecated or moved modules
"scrapy/conf.py",
"scrapy/log.py",
# not a test, but looks like a test
"scrapy/utils/testsite.py",
# contains scripts to be run by tests/test_crawler.py::CrawlerProcessSubprocess
*_py_files("tests/CrawlerProcess")
]
if (twisted_version.major, twisted_version.minor, twisted_version.micro) >= (15, 5, 0):
collect_ignore += _py_files("scrapy/xlib/tx")
if six.PY3:
for line in open('tests/py3-ignores.txt'):
file_path = line.strip()
if file_path and file_path[0] != '#':
collect_ignore.append(file_path)
for line in open('tests/ignores.txt'):
file_path = line.strip()
if file_path and file_path[0] != '#':
collect_ignore.append(file_path)
@pytest.fixture()
def chdir(tmpdir):
"""Change to pytest-provided temporary directory"""
tmpdir.chdir()
def pytest_collection_modifyitems(session, config, items):
# Avoid executing tests when executing `--flake8` flag (pytest-flake8)
try:
from pytest_flake8 import Flake8Item
if config.getoption('--flake8'):
items[:] = [item for item in items if isinstance(item, Flake8Item)]
except ImportError:
pass
@pytest.fixture(scope='class')
def reactor_pytest(request):
if not request.cls:
# doctests
return
request.cls.reactor_pytest = request.config.getoption("--reactor")
return request.cls.reactor_pytest
@pytest.fixture(autouse=True)
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')

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debian/scrapy.lintian-overrides vendored
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@ -1,2 +1 @@
new-package-should-close-itp-bug
extra-license-file usr/share/pyshared/scrapy/xlib/pydispatch/license.txt

3
docs/Makefile
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@ -82,6 +82,9 @@ pydoc-topics: build
@echo "Building finished; now copy build/pydoc-topics/pydoc_topics.py " \
"into the Lib/ directory"
coverage: BUILDER = coverage
coverage: build
htmlview: html
$(PYTHON) -c "import webbrowser, os; webbrowser.open('file://' + \
os.path.realpath('build/html/index.html'))"

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docs/_tests/quotes.html Normal file
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@ -0,0 +1,281 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Quotes to Scrape</title>
<link rel="stylesheet" href="/static/bootstrap.min.css">
<link rel="stylesheet" href="/static/main.css">
</head>
<body>
<div class="container">
<div class="row header-box">
<div class="col-md-8">
<h1>
<a href="/" style="text-decoration: none">Quotes to Scrape</a>
</h1>
</div>
<div class="col-md-4">
<p>
<a href="/login">Login</a>
</p>
</div>
</div>
<div class="row">
<div class="col-md-8">
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="change,deep-thoughts,thinking,world" / >
<a class="tag" href="/tag/change/page/1/">change</a>
<a class="tag" href="/tag/deep-thoughts/page/1/">deep-thoughts</a>
<a class="tag" href="/tag/thinking/page/1/">thinking</a>
<a class="tag" href="/tag/world/page/1/">world</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is our choices, Harry, that show what we truly are, far more than our abilities.”</span>
<span>by <small class="author" itemprop="author">J.K. Rowling</small>
<a href="/author/J-K-Rowling">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="abilities,choices" / >
<a class="tag" href="/tag/abilities/page/1/">abilities</a>
<a class="tag" href="/tag/choices/page/1/">choices</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“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.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="inspirational,life,live,miracle,miracles" / >
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/live/page/1/">live</a>
<a class="tag" href="/tag/miracle/page/1/">miracle</a>
<a class="tag" href="/tag/miracles/page/1/">miracles</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.”</span>
<span>by <small class="author" itemprop="author">Jane Austen</small>
<a href="/author/Jane-Austen">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="aliteracy,books,classic,humor" / >
<a class="tag" href="/tag/aliteracy/page/1/">aliteracy</a>
<a class="tag" href="/tag/books/page/1/">books</a>
<a class="tag" href="/tag/classic/page/1/">classic</a>
<a class="tag" href="/tag/humor/page/1/">humor</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Imperfection is beauty, madness is genius and it&#39;s better to be absolutely ridiculous than absolutely boring.”</span>
<span>by <small class="author" itemprop="author">Marilyn Monroe</small>
<a href="/author/Marilyn-Monroe">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="be-yourself,inspirational" / >
<a class="tag" href="/tag/be-yourself/page/1/">be-yourself</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Try not to become a man of success. Rather become a man of value.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="adulthood,success,value" / >
<a class="tag" href="/tag/adulthood/page/1/">adulthood</a>
<a class="tag" href="/tag/success/page/1/">success</a>
<a class="tag" href="/tag/value/page/1/">value</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is better to be hated for what you are than to be loved for what you are not.”</span>
<span>by <small class="author" itemprop="author">André Gide</small>
<a href="/author/Andre-Gide">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="life,love" / >
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/love/page/1/">love</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“I have not failed. I&#39;ve just found 10,000 ways that won&#39;t work.”</span>
<span>by <small class="author" itemprop="author">Thomas A. Edison</small>
<a href="/author/Thomas-A-Edison">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="edison,failure,inspirational,paraphrased" / >
<a class="tag" href="/tag/edison/page/1/">edison</a>
<a class="tag" href="/tag/failure/page/1/">failure</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/paraphrased/page/1/">paraphrased</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A woman is like a tea bag; you never know how strong it is until it&#39;s in hot water.”</span>
<span>by <small class="author" itemprop="author">Eleanor Roosevelt</small>
<a href="/author/Eleanor-Roosevelt">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="misattributed-eleanor-roosevelt" / >
<a class="tag" href="/tag/misattributed-eleanor-roosevelt/page/1/">misattributed-eleanor-roosevelt</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A day without sunshine is like, you know, night.”</span>
<span>by <small class="author" itemprop="author">Steve Martin</small>
<a href="/author/Steve-Martin">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="humor,obvious,simile" / >
<a class="tag" href="/tag/humor/page/1/">humor</a>
<a class="tag" href="/tag/obvious/page/1/">obvious</a>
<a class="tag" href="/tag/simile/page/1/">simile</a>
</div>
</div>
<nav>
<ul class="pager">
<li class="next">
<a href="/page/2/">Next <span aria-hidden="true">&rarr;</span></a>
</li>
</ul>
</nav>
</div>
<div class="col-md-4 tags-box">
<h2>Top Ten tags</h2>
<span class="tag-item">
<a class="tag" style="font-size: 28px" href="/tag/love/">love</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 26px" href="/tag/inspirational/">inspirational</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 26px" href="/tag/life/">life</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 24px" href="/tag/humor/">humor</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 22px" href="/tag/books/">books</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 14px" href="/tag/reading/">reading</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 10px" href="/tag/friendship/">friendship</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 8px" href="/tag/friends/">friends</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 8px" href="/tag/truth/">truth</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 6px" href="/tag/simile/">simile</a>
</span>
</div>
</div>
</div>
<footer class="footer">
<div class="container">
<p class="text-muted">
Quotes by: <a href="https://www.goodreads.com/quotes">GoodReads.com</a>
</p>
<p class="copyright">
Made with <span class='sh-red'>❤</span> by <a href="https://scrapinghub.com">Scrapinghub</a>
</p>
</div>
</footer>
</body>
</html>

281
docs/_tests/quotes1.html Normal file
View File

@ -0,0 +1,281 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Quotes to Scrape</title>
<link rel="stylesheet" href="/static/bootstrap.min.css">
<link rel="stylesheet" href="/static/main.css">
</head>
<body>
<div class="container">
<div class="row header-box">
<div class="col-md-8">
<h1>
<a href="/" style="text-decoration: none">Quotes to Scrape</a>
</h1>
</div>
<div class="col-md-4">
<p>
<a href="/login">Login</a>
</p>
</div>
</div>
<div class="row">
<div class="col-md-8">
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="change,deep-thoughts,thinking,world" / >
<a class="tag" href="/tag/change/page/1/">change</a>
<a class="tag" href="/tag/deep-thoughts/page/1/">deep-thoughts</a>
<a class="tag" href="/tag/thinking/page/1/">thinking</a>
<a class="tag" href="/tag/world/page/1/">world</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is our choices, Harry, that show what we truly are, far more than our abilities.”</span>
<span>by <small class="author" itemprop="author">J.K. Rowling</small>
<a href="/author/J-K-Rowling">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="abilities,choices" / >
<a class="tag" href="/tag/abilities/page/1/">abilities</a>
<a class="tag" href="/tag/choices/page/1/">choices</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“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.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="inspirational,life,live,miracle,miracles" / >
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/live/page/1/">live</a>
<a class="tag" href="/tag/miracle/page/1/">miracle</a>
<a class="tag" href="/tag/miracles/page/1/">miracles</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.”</span>
<span>by <small class="author" itemprop="author">Jane Austen</small>
<a href="/author/Jane-Austen">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="aliteracy,books,classic,humor" / >
<a class="tag" href="/tag/aliteracy/page/1/">aliteracy</a>
<a class="tag" href="/tag/books/page/1/">books</a>
<a class="tag" href="/tag/classic/page/1/">classic</a>
<a class="tag" href="/tag/humor/page/1/">humor</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Imperfection is beauty, madness is genius and it&#39;s better to be absolutely ridiculous than absolutely boring.”</span>
<span>by <small class="author" itemprop="author">Marilyn Monroe</small>
<a href="/author/Marilyn-Monroe">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="be-yourself,inspirational" / >
<a class="tag" href="/tag/be-yourself/page/1/">be-yourself</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Try not to become a man of success. Rather become a man of value.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="adulthood,success,value" / >
<a class="tag" href="/tag/adulthood/page/1/">adulthood</a>
<a class="tag" href="/tag/success/page/1/">success</a>
<a class="tag" href="/tag/value/page/1/">value</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is better to be hated for what you are than to be loved for what you are not.”</span>
<span>by <small class="author" itemprop="author">André Gide</small>
<a href="/author/Andre-Gide">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="life,love" / >
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/love/page/1/">love</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“I have not failed. I&#39;ve just found 10,000 ways that won&#39;t work.”</span>
<span>by <small class="author" itemprop="author">Thomas A. Edison</small>
<a href="/author/Thomas-A-Edison">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="edison,failure,inspirational,paraphrased" / >
<a class="tag" href="/tag/edison/page/1/">edison</a>
<a class="tag" href="/tag/failure/page/1/">failure</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/paraphrased/page/1/">paraphrased</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A woman is like a tea bag; you never know how strong it is until it&#39;s in hot water.”</span>
<span>by <small class="author" itemprop="author">Eleanor Roosevelt</small>
<a href="/author/Eleanor-Roosevelt">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="misattributed-eleanor-roosevelt" / >
<a class="tag" href="/tag/misattributed-eleanor-roosevelt/page/1/">misattributed-eleanor-roosevelt</a>
</div>
</div>
<div class="quote" itemscope itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A day without sunshine is like, you know, night.”</span>
<span>by <small class="author" itemprop="author">Steve Martin</small>
<a href="/author/Steve-Martin">(about)</a>
</span>
<div class="tags">
Tags:
<meta class="keywords" itemprop="keywords" content="humor,obvious,simile" / >
<a class="tag" href="/tag/humor/page/1/">humor</a>
<a class="tag" href="/tag/obvious/page/1/">obvious</a>
<a class="tag" href="/tag/simile/page/1/">simile</a>
</div>
</div>
<nav>
<ul class="pager">
<li class="next">
<a href="/page/2/">Next <span aria-hidden="true">&rarr;</span></a>
</li>
</ul>
</nav>
</div>
<div class="col-md-4 tags-box">
<h2>Top Ten tags</h2>
<span class="tag-item">
<a class="tag" style="font-size: 28px" href="/tag/love/">love</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 26px" href="/tag/inspirational/">inspirational</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 26px" href="/tag/life/">life</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 24px" href="/tag/humor/">humor</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 22px" href="/tag/books/">books</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 14px" href="/tag/reading/">reading</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 10px" href="/tag/friendship/">friendship</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 8px" href="/tag/friends/">friends</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 8px" href="/tag/truth/">truth</a>
</span>
<span class="tag-item">
<a class="tag" style="font-size: 6px" href="/tag/simile/">simile</a>
</span>
</div>
</div>
</div>
<footer class="footer">
<div class="container">
<p class="text-muted">
Quotes by: <a href="https://www.goodreads.com/quotes">GoodReads.com</a>
</p>
<p class="copyright">
Made with <span class='sh-red'>❤</span> by <a href="https://scrapinghub.com">Scrapinghub</a>
</p>
</div>
</footer>
</body>
</html>

86
docs/conf.py
View File

@ -12,6 +12,7 @@
# serve to show the default.
import sys
from datetime import datetime
from os import path
# If your extensions are in another directory, add it here. If the directory
@ -27,8 +28,13 @@ sys.path.insert(0, path.dirname(path.dirname(__file__)))
# Add any Sphinx extension module names here, as strings. They can be extensions
# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
extensions = [
'hoverxref.extension',
'notfound.extension',
'scrapydocs',
'sphinx.ext.autodoc'
'sphinx.ext.autodoc',
'sphinx.ext.coverage',
'sphinx.ext.intersphinx',
'sphinx.ext.viewcode',
]
# Add any paths that contain templates here, relative to this directory.
@ -44,8 +50,8 @@ source_suffix = '.rst'
master_doc = 'index'
# General information about the project.
project = u'Scrapy'
copyright = u'2008–2018, Scrapy developers'
project = 'Scrapy'
copyright = '2008–{}, Scrapy developers'.format(datetime.now().year)
# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
@ -73,6 +79,8 @@ language = 'en'
# List of documents that shouldn't be included in the build.
#unused_docs = []
exclude_patterns = ['build']
# List of directories, relative to source directory, that shouldn't be searched
# for source files.
exclude_trees = ['.build']
@ -187,8 +195,8 @@ htmlhelp_basename = 'Scrapydoc'
# Grouping the document tree into LaTeX files. List of tuples
# (source start file, target name, title, author, document class [howto/manual]).
latex_documents = [
('index', 'Scrapy.tex', u'Scrapy Documentation',
u'Scrapy developers', 'manual'),
('index', 'Scrapy.tex', 'Scrapy Documentation',
'Scrapy developers', 'manual'),
]
# The name of an image file (relative to this directory) to place at the top of
@ -218,3 +226,71 @@ linkcheck_ignore = [
'http://localhost:\d+', 'http://hg.scrapy.org',
'http://directory.google.com/'
]
# Options for the Coverage extension
# ----------------------------------
coverage_ignore_pyobjects = [
# Contract’s add_pre_hook and add_post_hook are not documented because
# they should be transparent to contract developers, for whom pre_hook and
# post_hook should be the actual concern.
r'\bContract\.add_(pre|post)_hook$',
# ContractsManager is an internal class, developers are not expected to
# interact with it directly in any way.
r'\bContractsManager\b$',
# For default contracts we only want to document their general purpose in
# their __init__ method, the methods they reimplement to achieve that purpose
# should be irrelevant to developers using those contracts.
r'\w+Contract\.(adjust_request_args|(pre|post)_process)$',
# Methods of downloader middlewares are not documented, only the classes
# themselves, since downloader middlewares are controlled through Scrapy
# settings.
r'^scrapy\.downloadermiddlewares\.\w*?\.(\w*?Middleware|DownloaderStats)\.',
# Base classes of downloader middlewares are implementation details that
# are not meant for users.
r'^scrapy\.downloadermiddlewares\.\w*?\.Base\w*?Middleware',
# Private exception used by the command-line interface implementation.
r'^scrapy\.exceptions\.UsageError',
# Methods of BaseItemExporter subclasses are only documented in
# BaseItemExporter.
r'^scrapy\.exporters\.(?!BaseItemExporter\b)\w*?\.',
# Extension behavior is only modified through settings. Methods of
# extension classes, as well as helper functions, are implementation
# details that are not documented.
r'^scrapy\.extensions\.[a-z]\w*?\.[A-Z]\w*?\.', # methods
r'^scrapy\.extensions\.[a-z]\w*?\.[a-z]', # helper functions
# Never documented before, and deprecated now.
r'^scrapy\.item\.DictItem$',
r'^scrapy\.linkextractors\.FilteringLinkExtractor$',
# Implementation detail of LxmlLinkExtractor
r'^scrapy\.linkextractors\.lxmlhtml\.LxmlParserLinkExtractor',
]
# Options for the InterSphinx extension
# -------------------------------------
intersphinx_mapping = {
'coverage': ('https://coverage.readthedocs.io/en/stable', 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),
'tox': ('https://tox.readthedocs.io/en/latest', None),
'twisted': ('https://twistedmatrix.com/documents/current', None),
'twistedapi': ('https://twistedmatrix.com/documents/current/api', None),
}
# Options for sphinx-hoverxref options
# ------------------------------------
hoverxref_auto_ref = True

29
docs/conftest.py Normal file
View File

@ -0,0 +1,29 @@
import os
from doctest import ELLIPSIS, NORMALIZE_WHITESPACE
from scrapy.http.response.html import HtmlResponse
from sybil import Sybil
from sybil.parsers.codeblock import CodeBlockParser
from sybil.parsers.doctest import DocTestParser
from sybil.parsers.skip import skip
def load_response(url, filename):
input_path = os.path.join(os.path.dirname(__file__), '_tests', filename)
with open(input_path, 'rb') as input_file:
return HtmlResponse(url, body=input_file.read())
def setup(namespace):
namespace['load_response'] = load_response
pytest_collect_file = Sybil(
parsers=[
DocTestParser(optionflags=ELLIPSIS | NORMALIZE_WHITESPACE),
CodeBlockParser(future_imports=['print_function']),
skip,
],
pattern='*.rst',
setup=setup,
).pytest()

91
docs/contributing.rst
View File

@ -44,7 +44,7 @@ guidelines when you're going to report a new bug.
* check the :ref:`FAQ <faq>` first to see if your issue is addressed in a
well-known question
* if you have a general question about scrapy usage, please ask it at
* if you have a general question about Scrapy usage, please ask it at
`Stack Overflow <https://stackoverflow.com/questions/tagged/scrapy>`__
(use "scrapy" tag).
@ -99,6 +99,15 @@ Well-written patches should:
the documentation changes in the same patch. See `Documentation policies`_
below.
* if you're adding a private API, please add a regular expression to the
``coverage_ignore_pyobjects`` variable of ``docs/conf.py`` to exclude the new
private API from documentation coverage checks.
To see if your private API is skipped properly, generate a documentation
coverage report as follows::
tox -e docs-coverage
.. _submitting-patches:
Submitting patches
@ -162,57 +171,77 @@ Scrapy:
See https://help.github.com/articles/setting-your-username-in-git/ for
setup instructions.
.. _documentation-policies:
Documentation policies
======================
* **Don't** use docstrings for documenting classes, or methods which are
already documented in the official (sphinx) documentation. Alternatively,
**do** provide a docstring, but make sure sphinx documentation uses
autodoc_ extension to pull the docstring. For example, the
:meth:`ItemLoader.add_value` method should be either
documented only in the sphinx documentation (not as a docstring), or
it should have a docstring which is pulled to sphinx documentation using
autodoc_ extension.
For reference documentation of API members (classes, methods, etc.) use
docstrings and make sure that the Sphinx documentation uses the
:mod:`~sphinx.ext.autodoc` extension to pull the docstrings. API reference
documentation should follow docstring conventions (`PEP 257`_) and be
IDE-friendly: short, to the point, and it may provide short examples.
* **Do** use docstrings for documenting functions not present in the official
(sphinx) documentation, such as functions from ``scrapy.utils`` package and
its sub-modules.
Other types of documentation, such as tutorials or topics, should be covered in
files within the ``docs/`` directory. This includes documentation that is
specific to an API member, but goes beyond API reference documentation.
.. _autodoc: http://www.sphinx-doc.org/en/stable/ext/autodoc.html
In any case, if something is covered in a docstring, use the
:mod:`~sphinx.ext.autodoc` extension to pull the docstring into the
documentation instead of duplicating the docstring in files within the
``docs/`` directory.
Tests
=====
Tests are implemented using the `Twisted unit-testing framework`_, running
tests requires `tox`_.
Tests are implemented using the :doc:`Twisted unit-testing framework
<twisted:core/development/policy/test-standard>`. Running tests requires
:doc:`tox <tox:index>`.
.. _running-tests:
Running tests
-------------
Make sure you have a recent enough `tox`_ installation:
To run all tests::
``tox --version``
If your version is older than 1.7.0, please update it first:
``pip install -U tox``
To run all tests go to the root directory of Scrapy source code and run:
``tox``
tox
To run a specific test (say ``tests/test_loader.py``) use:
``tox -- tests/test_loader.py``
To see coverage report install `coverage`_ (``pip install coverage``) and run:
To run the tests on a specific :doc:`tox <tox:index>` environment, use
``-e <name>`` with an environment name from ``tox.ini``. For example, to run
the tests with Python 3.6 use::
tox -e py36
You can also specify a comma-separated list of environments, and use :ref:`tox’s
parallel mode <tox:parallel_mode>` to run the tests on multiple environments in
parallel::
tox -e py36,py38 -p auto
To pass command-line options to :doc:`pytest <pytest:index>`, add them after
``--`` in your call to :doc:`tox <tox:index>`. Using ``--`` overrides the
default positional arguments defined in ``tox.ini``, so you must include those
default positional arguments (``scrapy tests``) after ``--`` as well::
tox -- scrapy tests -x # stop after first failure
You can also use the `pytest-xdist`_ plugin. For example, to run all tests on
the Python 3.6 :doc:`tox <tox:index>` environment using all your CPU cores::
tox -e py36 -- scrapy tests -n auto
To see coverage report install :doc:`coverage <coverage:index>`
(``pip install coverage``) and run:
``coverage report``
see output of ``coverage --help`` for more options like html or xml report.
.. _coverage: https://pypi.python.org/pypi/coverage
Writing tests
-------------
@ -233,9 +262,9 @@ And their unit-tests are in::
.. _issue tracker: https://github.com/scrapy/scrapy/issues
.. _scrapy-users: https://groups.google.com/forum/#!forum/scrapy-users
.. _Scrapy subreddit: https://reddit.com/r/scrapy
.. _Twisted unit-testing framework: https://twistedmatrix.com/documents/current/core/development/policy/test-standard.html
.. _AUTHORS: https://github.com/scrapy/scrapy/blob/master/AUTHORS
.. _tests/: https://github.com/scrapy/scrapy/tree/master/tests
.. _open issues: https://github.com/scrapy/scrapy/issues
.. _pull request: https://help.github.com/send-pull-requests/
.. _tox: https://pypi.python.org/pypi/tox
.. _PEP 257: https://www.python.org/dev/peps/pep-0257/
.. _pull request: https://help.github.com/en/articles/creating-a-pull-request
.. _pytest-xdist: https://github.com/pytest-dev/pytest-xdist

59
docs/faq.rst
View File

@ -69,11 +69,11 @@ Here's an example spider using BeautifulSoup API, with ``lxml`` as the HTML pars
What Python versions does Scrapy support?
-----------------------------------------
Scrapy is supported under Python 2.7 and Python 3.4+
Scrapy is supported under Python 3.5+
under CPython (default Python implementation) and PyPy (starting with PyPy 5.9).
Python 2.6 support was dropped starting at Scrapy 0.20.
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
@ -129,13 +129,23 @@ Does Scrapy crawl in breadth-first or depth-first order?
By default, Scrapy uses a `LIFO`_ queue for storing pending requests, which
basically means that it crawls in `DFO order`_. This order is more convenient
in most cases. If you do want to crawl in true `BFO order`_, you can do it by
in most cases.
If you do want to crawl in true `BFO order`_, you can do it by
setting the following settings::
DEPTH_PRIORITY = 1
SCHEDULER_DISK_QUEUE = 'scrapy.squeues.PickleFifoDiskQueue'
SCHEDULER_MEMORY_QUEUE = 'scrapy.squeues.FifoMemoryQueue'
While pending requests are below the configured values of
:setting:`CONCURRENT_REQUESTS`, :setting:`CONCURRENT_REQUESTS_PER_DOMAIN` or
:setting:`CONCURRENT_REQUESTS_PER_IP`, those requests are sent
concurrently. As a result, the first few requests of a crawl rarely follow the
desired order. Lowering those settings to ``1`` enforces the desired order, but
it significantly slows down the crawl as a whole.
My Scrapy crawler has memory leaks. What can I do?
--------------------------------------------------
@ -319,6 +329,49 @@ I'm scraping a XML document and my XPath selector doesn't return any items
You may need to remove namespaces. See :ref:`removing-namespaces`.
.. _faq-split-item:
How to split an item into multiple items in an item pipeline?
-------------------------------------------------------------
:ref:`Item pipelines <topics-item-pipeline>` cannot yield multiple items per
input item. :ref:`Create a spider middleware <custom-spider-middleware>`
instead, and use its
:meth:`~scrapy.spidermiddlewares.SpiderMiddleware.process_spider_output`
method for this purpose. For example::
from copy import deepcopy
from scrapy.item import BaseItem
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']):
yield deepcopy(item)
Does Scrapy support IPv6 addresses?
-----------------------------------
Yes, by setting :setting:`DNS_RESOLVER` to ``scrapy.resolver.CachingHostnameResolver``.
Note that by doing so, you lose the ability to set a specific timeout for DNS requests
(the value of the :setting:`DNS_TIMEOUT` setting is ignored).
.. _faq-specific-reactor:
How to deal with ``<class 'ValueError'>: filedescriptor out of range in select()`` exceptions?
----------------------------------------------------------------------------------------------
This issue `has been reported`_ to appear when running broad crawls in macOS, where the default
Twisted reactor is :class:`twisted.internet.selectreactor.SelectReactor`. Switching to a
different reactor is possible by using the :setting:`TWISTED_REACTOR` setting.
.. _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)
.. _DFO order: https://en.wikipedia.org/wiki/Depth-first_search

6
docs/index.rst
View File

@ -158,6 +158,7 @@ Solving specific problems
topics/practices
topics/broad-crawls
topics/developer-tools
topics/dynamic-content
topics/leaks
topics/media-pipeline
topics/deploy
@ -169,7 +170,7 @@ Solving specific problems
Get answers to most frequently asked questions.
:doc:`topics/debug`
Learn how to debug common problems of your scrapy spider.
Learn how to debug common problems of your Scrapy spider.
:doc:`topics/contracts`
Learn how to use contracts for testing your spiders.
@ -183,6 +184,9 @@ Solving specific problems
:doc:`topics/developer-tools`
Learn how to scrape with your browser's developer tools.
:doc:`topics/dynamic-content`
Read webpage data that is loaded dynamically.
:doc:`topics/leaks`
Learn how to find and get rid of memory leaks in your crawler.

36
docs/intro/install.rst
View File

@ -7,7 +7,7 @@ Installation guide
Installing Scrapy
=================
Scrapy runs on Python 2.7 and Python 3.4 or above
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
@ -78,9 +78,9 @@ TL;DR: We recommend installing Scrapy inside a virtual environment
on all platforms.
Python packages can be installed either globally (a.k.a system wide),
or in user-space. We do not recommend installing scrapy system wide.
or in user-space. We do not recommend installing Scrapy system wide.
Instead, we recommend that you install scrapy within a so-called
Instead, we recommend that you install Scrapy within a so-called
"virtual environment" (`virtualenv`_).
Virtualenvs allow you to not conflict with already-installed Python
system packages (which could break some of your system tools and scripts),
@ -97,15 +97,13 @@ Check this `user guide`_ on how to create your virtualenv.
.. note::
If you use Linux or OS X, `virtualenvwrapper`_ is a handy tool to create virtualenvs.
Once you have created a virtualenv, you can install scrapy inside it with ``pip``,
Once you have created a virtualenv, you can install Scrapy inside it with ``pip``,
just like any other Python package.
(See :ref:`platform-specific guides <intro-install-platform-notes>`
below for non-Python dependencies that you may need to install beforehand).
Python virtualenvs can be created to use Python 2 by default, or Python 3 by default.
* If you want to install scrapy with Python 3, install scrapy within a Python 3 virtualenv.
* And if you want to install scrapy with Python 2, install scrapy within a Python 2 virtualenv.
Python virtualenvs can be created to use Python 2 by default, or Python 3 by default. As Scrapy
only supports Python 3, make sure you created a Python 3 virtualenv.
.. _virtualenv: https://virtualenv.pypa.io
.. _virtualenv installation instructions: https://virtualenv.pypa.io/en/stable/installation/
@ -146,19 +144,15 @@ albeit with potential issues with TLS connections.
typically too old and slow to catch up with latest Scrapy.
To install scrapy on Ubuntu (or Ubuntu-based) systems, you need to install
To install Scrapy on Ubuntu (or Ubuntu-based) systems, you need to install
these dependencies::
sudo apt-get install python-dev python-pip libxml2-dev libxslt1-dev zlib1g-dev libffi-dev libssl-dev
sudo apt-get install python3 python3-dev python3-pip libxml2-dev libxslt1-dev zlib1g-dev libffi-dev libssl-dev
- ``python-dev``, ``zlib1g-dev``, ``libxml2-dev`` and ``libxslt1-dev``
- ``python3-dev``, ``zlib1g-dev``, ``libxml2-dev`` and ``libxslt1-dev``
are required for ``lxml``
- ``libssl-dev`` and ``libffi-dev`` are required for ``cryptography``
If you want to install scrapy on Python 3, you’ll also need Python 3 development headers::
sudo apt-get install python3 python3-dev
Inside a :ref:`virtualenv <intro-using-virtualenv>`,
you can install Scrapy with ``pip`` after that::
@ -231,17 +225,17 @@ 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.
Most Scrapy dependencides now have binary wheels for CPython, but not for PyPy.
This means that these dependecies will be built during installation.
On OS X, 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>`_,
that is to ``brew install openssl`` and then export the flags that this command
recommends (only needed when installing scrapy). Installing on Linux has no special
recommends (only needed when installing Scrapy). Installing on Linux has no special
issues besides installing build dependencies.
Installing scrapy with PyPy on Windows is not tested.
Installing Scrapy with PyPy on Windows is not tested.
You can check that scrapy is installed correctly by running ``scrapy bench``.
You can check that Scrapy is installed correctly by running ``scrapy bench``.
If this command gives errors such as
``TypeError: ... got 2 unexpected keyword arguments``, this means
that setuptools was unable to pick up one PyPy-specific dependency.
@ -278,7 +272,7 @@ For details, see `Issue #2473 <https://github.com/scrapy/scrapy/issues/2473>`_.
.. _Python: https://www.python.org/
.. _pip: https://pip.pypa.io/en/latest/installing/
.. _lxml: http://lxml.de/
.. _lxml: https://lxml.de/index.html
.. _parsel: https://pypi.python.org/pypi/parsel
.. _w3lib: https://pypi.python.org/pypi/w3lib
.. _twisted: https://twistedmatrix.com/
@ -290,5 +284,5 @@ For details, see `Issue #2473 <https://github.com/scrapy/scrapy/issues/2473>`_.
.. _zsh: https://www.zsh.org/
.. _Scrapinghub: https://scrapinghub.com
.. _Anaconda: https://docs.anaconda.com/anaconda/
.. _Miniconda: https://conda.io/docs/user-guide/install/index.html
.. _Miniconda: https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html
.. _conda-forge: https://conda-forge.org/

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@ -34,8 +34,8 @@ http://quotes.toscrape.com, following the pagination::
def parse(self, response):
for quote in response.css('div.quote'):
yield {
'text': quote.css('span.text::text').get(),
'author': quote.xpath('span/small/text()').get(),
'text': quote.css('span.text::text').get(),
}
next_page = response.css('li.next a::attr("href")').get()

185
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@ -78,9 +78,9 @@ Our first Spider
Spiders are classes that you define and that Scrapy uses to scrape information
from a website (or a group of websites). They must subclass
:class:`scrapy.Spider` and define the initial requests to make, optionally how
to follow links in the pages, and how to parse the downloaded page content to
extract data.
:class:`~scrapy.spiders.Spider` and define the initial requests to make,
optionally how to follow links in the pages, and how to parse the downloaded
page content to extract data.
This is the code for our first Spider. Save it in a file named
``quotes_spider.py`` under the ``tutorial/spiders`` directory in your project::
@ -205,7 +205,7 @@ Extracting data
---------------
The best way to learn how to extract data with Scrapy is trying selectors
using the shell :ref:`Scrapy shell <topics-shell>`. Run::
using the :ref:`Scrapy shell <topics-shell>`. Run::
scrapy shell 'http://quotes.toscrape.com/page/1/'
@ -235,13 +235,16 @@ You will see something like::
[s] shelp() Shell help (print this help)
[s] fetch(req_or_url) Fetch request (or URL) and update local objects
[s] view(response) View response in a browser
>>>
Using the shell, you can try selecting elements using `CSS`_ with the response
object::
object:
>>> response.css('title')
[<Selector xpath='descendant-or-self::title' data='<title>Quotes to Scrape</title>'>]
.. invisible-code-block: python
response = load_response('http://quotes.toscrape.com/page/1/', 'quotes1.html')
>>> response.css('title')
[<Selector xpath='descendant-or-self::title' data='<title>Quotes to Scrape</title>'>]
The result of running ``response.css('title')`` is a list-like object called
:class:`~scrapy.selector.SelectorList`, which represents a list of
@ -249,30 +252,30 @@ The result of running ``response.css('title')`` is a list-like object called
and allow you to run further queries to fine-grain the selection or extract the
data.
To extract the text from the title above, you can do::
To extract the text from the title above, you can do:
>>> response.css('title::text').getall()
['Quotes to Scrape']
>>> response.css('title::text').getall()
['Quotes to Scrape']
There are two things to note here: one is that we've added ``::text`` to the
CSS query, to mean we want to select only the text elements directly inside
``<title>`` element. If we don't specify ``::text``, we'd get the full title
element, including its tags::
element, including its tags:
>>> response.css('title').getall()
['<title>Quotes to Scrape</title>']
>>> response.css('title').getall()
['<title>Quotes to Scrape</title>']
The other thing is that the result of calling ``.getall()`` is a list: it is
possible that a selector returns more than one result, so we extract them all.
When you know you just want the first result, as in this case, you can do::
When you know you just want the first result, as in this case, you can do:
>>> response.css('title::text').get()
'Quotes to Scrape'
>>> response.css('title::text').get()
'Quotes to Scrape'
As an alternative, you could've written::
As an alternative, you could've written:
>>> response.css('title::text')[0].get()
'Quotes to Scrape'
>>> response.css('title::text')[0].get()
'Quotes to Scrape'
However, using ``.get()`` directly on a :class:`~scrapy.selector.SelectorList`
instance avoids an ``IndexError`` and returns ``None`` when it doesn't
@ -285,19 +288,19 @@ 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`_::
expressions`_:
>>> response.css('title::text').re(r'Quotes.*')
['Quotes to Scrape']
>>> response.css('title::text').re(r'Q\w+')
['Quotes']
>>> response.css('title::text').re(r'(\w+) to (\w+)')
['Quotes', 'Scrape']
>>> response.css('title::text').re(r'Quotes.*')
['Quotes to Scrape']
>>> response.css('title::text').re(r'Q\w+')
['Quotes']
>>> response.css('title::text').re(r'(\w+) to (\w+)')
['Quotes', 'Scrape']
In order to find the proper CSS selectors to use, you might find useful opening
the response page from the shell in your web browser using ``view(response)``.
You can use your browser developer tools to inspect the HTML and come up
with a selector (see section about :ref:`topics-developer-tools`).
You can use your browser's developer tools to inspect the HTML and come up
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.
@ -309,12 +312,12 @@ visually selected elements, which works in many browsers.
XPath: a brief intro
^^^^^^^^^^^^^^^^^^^^
Besides `CSS`_, Scrapy selectors also support using `XPath`_ expressions::
Besides `CSS`_, Scrapy selectors also support using `XPath`_ expressions:
>>> response.xpath('//title')
[<Selector xpath='//title' data='<title>Quotes to Scrape</title>'>]
>>> response.xpath('//title/text()').get()
'Quotes to Scrape'
>>> response.xpath('//title')
[<Selector xpath='//title' data='<title>Quotes to Scrape</title>'>]
>>> response.xpath('//title/text()').get()
'Quotes to Scrape'
XPath expressions are very powerful, and are the foundation of Scrapy
Selectors. In fact, CSS selectors are converted to XPath under-the-hood. You
@ -369,45 +372,53 @@ we want::
$ scrapy shell 'http://quotes.toscrape.com'
We get a list of selectors for the quote HTML elements with::
We get a list of selectors for the quote HTML elements with:
>>> response.css("div.quote")
>>> response.css("div.quote")
[<Selector xpath="descendant-or-self::div[@class and contains(concat(' ', normalize-space(@class), ' '), ' quote ')]" data='<div class="quote" itemscope itemtype...'>,
<Selector xpath="descendant-or-self::div[@class and contains(concat(' ', normalize-space(@class), ' '), ' quote ')]" data='<div class="quote" itemscope itemtype...'>,
...]
Each of the selectors returned by the query above allows us to run further
queries over their sub-elements. Let's assign the first selector to a
variable, so that we can run our CSS selectors directly on a particular quote::
variable, so that we can run our CSS selectors directly on a particular quote:
>>> quote = response.css("div.quote")[0]
>>> quote = response.css("div.quote")[0]
Now, let's extract ``title``, ``author`` and the ``tags`` from that quote
using the ``quote`` object we just created::
Now, let's extract ``text``, ``author`` and the ``tags`` from that quote
using the ``quote`` object we just created:
>>> title = quote.css("span.text::text").get()
>>> title
'“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”'
>>> author = quote.css("small.author::text").get()
>>> author
'Albert Einstein'
>>> text = quote.css("span.text::text").get()
>>> text
'“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”'
>>> author = quote.css("small.author::text").get()
>>> author
'Albert Einstein'
Given that the tags are a list of strings, we can use the ``.getall()`` method
to get all of them::
to get all of them:
>>> tags = quote.css("div.tags a.tag::text").getall()
>>> tags
['change', 'deep-thoughts', 'thinking', 'world']
>>> tags = quote.css("div.tags a.tag::text").getall()
>>> tags
['change', 'deep-thoughts', 'thinking', 'world']
.. invisible-code-block: python
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::
quotes elements and put them together into a Python dictionary:
>>> for quote in response.css("div.quote"):
... text = quote.css("span.text::text").get()
... author = quote.css("small.author::text").get()
... tags = quote.css("div.tags a.tag::text").getall()
... print(dict(text=text, author=author, tags=tags))
{'tags': ['change', 'deep-thoughts', 'thinking', 'world'], 'author': 'Albert Einstein', 'text': '“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”'}
{'tags': ['abilities', 'choices'], 'author': 'J.K. Rowling', 'text': '“It is our choices, Harry, that show what we truly are, far more than our abilities.”'}
... a few more of these, omitted for brevity
>>>
>>> for quote in response.css("div.quote"):
... text = quote.css("span.text::text").get()
... author = quote.css("small.author::text").get()
... tags = quote.css("div.tags a.tag::text").getall()
... print(dict(text=text, author=author, tags=tags))
{'text': '“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”', 'author': 'Albert Einstein', 'tags': ['change', 'deep-thoughts', 'thinking', 'world']}
{'text': '“It is our choices, Harry, that show what we truly are, far more than our abilities.”', 'author': 'J.K. Rowling', 'tags': ['abilities', 'choices']}
...
Extracting data in our spider
-----------------------------
@ -505,23 +516,23 @@ markup:
</li>
</ul>
We can try extracting it in the shell::
We can try extracting it in the shell:
>>> response.css('li.next a').get()
'<a href="/page/2/">Next <span aria-hidden="true">→</span></a>'
>>> response.css('li.next a').get()
'<a href="/page/2/">Next <span aria-hidden="true">→</span></a>'
This gets the anchor element, but we want the attribute ``href``. For that,
Scrapy supports a CSS extension that let's you select the attribute contents,
like this::
Scrapy supports a CSS extension that lets you select the attribute contents,
like this:
>>> response.css('li.next a::attr(href)').get()
'/page/2/'
>>> response.css('li.next a::attr(href)').get()
'/page/2/'
There is also an ``attrib`` property available
(see :ref:`selecting-attributes` for more)::
(see :ref:`selecting-attributes` for more):
>>> response.css('li.next a').attrib['href']
'/page/2'
>>> response.css('li.next a').attrib['href']
'/page/2/'
Let's see now our spider modified to recursively follow the link to the next
page, extracting data from it::
@ -605,21 +616,25 @@ instance; you still have to yield this Request.
You can also pass a selector to ``response.follow`` instead of a string;
this selector should extract necessary attributes::
for href in response.css('li.next a::attr(href)'):
for href in response.css('ul.pager a::attr(href)'):
yield response.follow(href, callback=self.parse)
For ``<a>`` elements there is a shortcut: ``response.follow`` uses their href
attribute automatically. So the code can be shortened further::
for a in response.css('li.next a'):
for a in response.css('ul.pager a'):
yield response.follow(a, callback=self.parse)
.. note::
To create multiple requests from an iterable, you can use
:meth:`response.follow_all <scrapy.http.TextResponse.follow_all>` instead::
anchors = response.css('ul.pager a')
yield from response.follow_all(anchors, callback=self.parse)
or, shortening it further::
yield from response.follow_all(css='ul.pager a', callback=self.parse)
``response.follow(response.css('li.next a'))`` is not valid because
``response.css`` returns a list-like object with selectors for all results,
not a single selector. A ``for`` loop like in the example above, or
``response.follow(response.css('li.next a')[0])`` is fine.
More examples and patterns
--------------------------
@ -636,13 +651,11 @@ this time for scraping author information::
start_urls = ['http://quotes.toscrape.com/']
def parse(self, response):
# follow links to author pages
for href in response.css('.author + a::attr(href)'):
yield response.follow(href, self.parse_author)
author_page_links = response.css('.author + a')
yield from response.follow_all(author_page_links, self.parse_author)
# follow pagination links
for href in response.css('li.next a::attr(href)'):
yield response.follow(href, self.parse)
pagination_links = response.css('li.next a')
yield from response.follow_all(pagination_links, self.parse)
def parse_author(self, response):
def extract_with_css(query):
@ -658,8 +671,10 @@ This spider will start from the main page, it will follow all the links to the
authors pages calling the ``parse_author`` callback for each of them, and also
the pagination links with the ``parse`` callback as we saw before.
Here we're passing callbacks to ``response.follow`` as positional arguments
to make the code shorter; it also works for ``scrapy.Request``.
Here we're passing callbacks to
:meth:`response.follow_all <scrapy.http.TextResponse.follow_all>` as positional
arguments to make the code shorter; it also works for
:class:`~scrapy.http.Request`.
The ``parse_author`` callback defines a helper function to extract and cleanup the
data from a CSS query and yields the Python dict with the author data.

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6
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@ -1,2 +1,4 @@
Sphinx>=1.6
sphinx_rtd_theme
Sphinx>=2.1
sphinx-hoverxref
sphinx-notfound-page
sphinx_rtd_theme

6
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@ -99,6 +99,8 @@ how you :ref:`configure the downloader middlewares
Returns a deferred that is fired when the crawl is finished.
.. automethod:: stop
.. autoclass:: CrawlerRunner
:members:
@ -154,7 +156,7 @@ Settings API
SpiderLoader API
================
.. module:: scrapy.loader
.. module:: scrapy.spiderloader
:synopsis: The spider loader
.. class:: SpiderLoader
@ -271,5 +273,3 @@ class (which they all inherit from).
Close the given spider. After this is called, no more specific stats
can be accessed or collected.
.. _reactor: https://twistedmatrix.com/documents/current/core/howto/reactor-basics.html

3
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@ -166,11 +166,10 @@ for concurrency.
For more information about asynchronous programming and Twisted see these
links:
* `Introduction to Deferreds in Twisted`_
* :doc:`twisted:core/howto/defer-intro`
* `Twisted - hello, asynchronous programming`_
* `Twisted Introduction - Krondo`_
.. _Twisted: https://twistedmatrix.com/trac/
.. _Introduction to Deferreds in Twisted: https://twistedmatrix.com/documents/current/core/howto/defer-intro.html
.. _Twisted - hello, asynchronous programming: http://jessenoller.com/blog/2009/02/11/twisted-hello-asynchronous-programming/
.. _Twisted Introduction - Krondo: http://krondo.com/an-introduction-to-asynchronous-programming-and-twisted/

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@ -11,7 +11,7 @@ Design goals
============
1. be nicer to sites instead of using default download delay of zero
2. automatically adjust scrapy to the optimum crawling speed, so the user
2. automatically adjust Scrapy to the optimum crawling speed, so the user
doesn't have to tune the download delays to find the optimum one.
The user only needs to specify the maximum concurrent requests
it allows, and the extension does the rest.

71
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@ -39,24 +39,50 @@ you need to keep in mind when using Scrapy for doing broad crawls, along with
concrete suggestions of Scrapy settings to tune in order to achieve an
efficient broad crawl.
.. _broad-crawls-scheduler-priority-queue:
Use the right :setting:`SCHEDULER_PRIORITY_QUEUE`
=================================================
Scrapy’s default scheduler priority queue is ``'scrapy.pqueues.ScrapyPriorityQueue'``.
It works best during single-domain crawl. It does not work well with crawling
many different domains in parallel
To apply the recommended priority queue use::
SCHEDULER_PRIORITY_QUEUE = 'scrapy.pqueues.DownloaderAwarePriorityQueue'
.. _broad-crawls-concurrency:
Increase concurrency
====================
Concurrency is the number of requests that are processed in parallel. There is
a global limit and a per-domain limit.
a global limit (:setting:`CONCURRENT_REQUESTS`) and an additional limit that
can be set either per domain (:setting:`CONCURRENT_REQUESTS_PER_DOMAIN`) or per
IP (:setting:`CONCURRENT_REQUESTS_PER_IP`).
.. note:: The scheduler priority queue :ref:`recommended for broad crawls
<broad-crawls-scheduler-priority-queue>` does not support
:setting:`CONCURRENT_REQUESTS_PER_IP`.
The default global concurrency limit in Scrapy is not suitable for crawling
many different domains in parallel, so you will want to increase it. How much
to increase it will depend on how much CPU you crawler will have available. A
good starting point is ``100``, but the best way to find out is by doing some
trials and identifying at what concurrency your Scrapy process gets CPU
bounded. For optimum performance, you should pick a concurrency where CPU usage
is at 80-90%.
to increase it will depend on how much CPU and memory you crawler will have
available.
To increase the global concurrency use::
A good starting point is ``100``::
CONCURRENT_REQUESTS = 100
But the best way to find out is by doing some trials and identifying at what
concurrency your Scrapy process gets CPU bounded. For optimum performance, you
should pick a concurrency where CPU usage is at 80-90%.
Increasing concurrency also increases memory usage. If memory usage is a
concern, you might need to lower your global concurrency limit accordingly.
Increase Twisted IO thread pool maximum size
============================================
@ -85,7 +111,7 @@ When doing broad crawls you are often only interested in the crawl rates you
get and any errors found. These stats are reported by Scrapy when using the
``INFO`` log level. In order to save CPU (and log storage requirements) you
should not use ``DEBUG`` log level when preforming large broad crawls in
production. Using ``DEBUG`` level when developing your (broad) crawler may be
production. Using ``DEBUG`` level when developing your (broad) crawler may be
fine though.
To set the log level use::
@ -163,3 +189,32 @@ It is turned OFF by default because it has some performance overhead,
and enabling it for focused crawls doesn't make much sense.
.. _ajax crawlable: https://developers.google.com/webmasters/ajax-crawling/docs/getting-started
.. _broad-crawls-bfo:
Crawl in BFO order
==================
:ref:`Scrapy crawls in DFO order by default <faq-bfo-dfo>`.
In broad crawls, however, page crawling tends to be faster than page
processing. As a result, unprocessed early requests stay in memory until the
final depth is reached, which can significantly increase memory usage.
:ref:`Crawl in BFO order <faq-bfo-dfo>` instead to save memory.
Be mindful of memory leaks
==========================
If your broad crawl shows a high memory usage, in addition to :ref:`crawling in
BFO order <broad-crawls-bfo>` and :ref:`lowering concurrency
<broad-crawls-concurrency>` you should :ref:`debug your memory leaks
<topics-leaks>`.
Install a specific Twisted reactor
==================================
If the crawl is exceeding the system's capabilities, you might want to try
installing a specific Twisted reactor, via the :setting:`TWISTED_REACTOR` setting.

33
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@ -1,3 +1,5 @@
.. highlight:: none
.. _topics-commands:
=================
@ -27,7 +29,7 @@ in standard locations:
1. ``/etc/scrapy.cfg`` or ``c:\scrapy\scrapy.cfg`` (system-wide),
2. ``~/.config/scrapy.cfg`` (``$XDG_CONFIG_HOME``) and ``~/.scrapy.cfg`` (``$HOME``)
for global (user-wide) settings, and
3. ``scrapy.cfg`` inside a scrapy project's root (see next section).
3. ``scrapy.cfg`` inside a Scrapy project's root (see next section).
Settings from these files are merged in the listed order of preference:
user-defined values have higher priority than system-wide defaults
@ -66,7 +68,9 @@ structure by default, similar to this::
The directory where the ``scrapy.cfg`` file resides is known as the *project
root directory*. That file contains the name of the python module that defines
the project settings. Here is an example::
the project settings. Here is an example:
.. code-block:: ini
[settings]
default = myproject.settings
@ -80,7 +84,9 @@ A project root directory, the one that contains the ``scrapy.cfg``, may be
shared by multiple Scrapy projects, each with its own settings module.
In that case, you must define one or more aliases for those settings modules
under ``[settings]`` in your ``scrapy.cfg`` file::
under ``[settings]`` in your ``scrapy.cfg`` file:
.. code-block:: ini
[settings]
default = myproject1.settings
@ -277,6 +283,8 @@ check
Run contract checks.
.. skip: start
Usage examples::
$ scrapy check -l
@ -294,6 +302,8 @@ Usage examples::
[FAILED] first_spider:parse
>>> Returned 92 requests, expected 0..4
.. skip: end
.. command:: list
list
@ -461,6 +471,9 @@ Supported options:
* ``--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.
This must be a valid json string. Example: --cbkwargs='{"foo" : "bar"}'
* ``--pipelines``: process items through pipelines
* ``--rules`` or ``-r``: use :class:`~scrapy.spiders.CrawlSpider`
@ -478,6 +491,8 @@ Supported options:
* ``--verbose`` or ``-v``: display information for each depth level
.. skip: start
Usage example::
$ scrapy parse http://www.example.com/ -c parse_item
@ -492,6 +507,8 @@ Usage example::
# Requests -----------------------------------------------------------------
[]
.. skip: end
.. command:: settings
@ -570,7 +587,9 @@ Default: ``''`` (empty string)
A module to use for looking up custom Scrapy commands. This is used to add custom
commands for your Scrapy project.
Example::
Example:
.. code-block:: python
COMMANDS_MODULE = 'mybot.commands'
@ -585,7 +604,11 @@ 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.
The following example adds ``my_command`` command::
The following example adds ``my_command`` command:
.. skip: next
.. code-block:: python
from setuptools import setup, find_packages

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@ -6,10 +6,6 @@ Spiders Contracts
.. versionadded:: 0.15
.. note:: This is a new feature (introduced in Scrapy 0.15) and may be subject
to minor functionality/API updates. Check the :ref:`release notes <news>` to
be notified of updates.
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.
@ -35,12 +31,20 @@ This callback is tested using three built-in contracts:
.. class:: UrlContract
This contract (``@url``) sets the sample url used when checking other
This contract (``@url``) sets the sample URL used when checking other
contract conditions for this spider. This contract is mandatory. All
callbacks lacking this contract are ignored when running the checks::
@url url
.. class:: CallbackKeywordArgumentsContract
This contract (``@cb_kwargs``) sets the :attr:`cb_kwargs <scrapy.http.Request.cb_kwargs>`
attribute for the sample request. It must be a valid JSON dictionary.
::
@cb_kwargs {"arg1": "value1", "arg2": "value2", ...}
.. class:: ReturnsContract
This contract (``@returns``) sets lower and upper bounds for the items and
@ -60,7 +64,7 @@ Use the :command:`check` command to run the contract checks.
Custom Contracts
================
If you find you need more power than the built-in scrapy contracts you can
If you find you need more power than the built-in Scrapy contracts you can
create and load your own contracts in the project by using the
:setting:`SPIDER_CONTRACTS` setting::
@ -69,7 +73,7 @@ create and load your own contracts in the project by using the
'myproject.contracts.ItemValidate': 10,
}
Each contract must inherit from :class:`scrapy.contracts.Contract` and can
Each contract must inherit from :class:`~scrapy.contracts.Contract` and can
override three methods:
.. module:: scrapy.contracts
@ -102,9 +106,14 @@ override three methods:
This allows processing the output of the callback. Iterators are
converted listified before being passed to this hook.
Raise :class:`~scrapy.exceptions.ContractFail` from
:class:`~scrapy.contracts.Contract.pre_process` or
:class:`~scrapy.contracts.Contract.post_process` if expectations are not met:
.. autoclass:: scrapy.exceptions.ContractFail
Here is a demo contract which checks the presence of a custom header in the
response received. Raise :class:`scrapy.exceptions.ContractFail` in order to
get the failures pretty printed::
response received::
from scrapy.contracts import Contract
from scrapy.exceptions import ContractFail
@ -120,3 +129,24 @@ get the failures pretty printed::
for header in self.args:
if header not in response.headers:
raise ContractFail('X-CustomHeader not present')
.. _detecting-contract-check-runs:
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
your spiders or your settings when ``scrapy check`` is used::
import os
import scrapy
class ExampleSpider(scrapy.Spider):
name = 'example'
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

23
docs/topics/debug.rst
View File

@ -5,7 +5,7 @@ Debugging Spiders
=================
This document explains the most common techniques for debugging spiders.
Consider the following scrapy spider below::
Consider the following Scrapy spider below::
import scrapy
from myproject.items import MyItem
@ -28,16 +28,15 @@ Consider the following scrapy spider below::
item = MyItem()
# populate `item` fields
# and extract item_details_url
yield scrapy.Request(item_details_url, self.parse_details, meta={'item': item})
yield scrapy.Request(item_details_url, self.parse_details, cb_kwargs={'item': item})
def parse_details(self, response):
item = response.meta['item']
def parse_details(self, response, item):
# populate more `item` fields
return item
Basically this is a simple spider which parses two pages of items (the
start_urls). Items also have a details page with additional information, so we
use the ``meta`` functionality of :class:`~scrapy.http.Request` to pass a
use the ``cb_kwargs`` functionality of :class:`~scrapy.http.Request` to pass a
partially populated item.
@ -49,6 +48,10 @@ The most basic way of checking the output of your spider is to use the
of the spider at the method level. It has the advantage of being flexible and
simple to use, but does not allow debugging code inside a method.
.. highlight:: none
.. skip: start
In order to see the item scraped from a specific url::
$ scrapy parse --spider=myspider -c parse_item -d 2 <item_url>
@ -86,6 +89,8 @@ using::
$ scrapy parse --spider=myspider -d 3 'http://example.com/page1'
.. skip: end
Scrapy Shell
============
@ -95,13 +100,14 @@ spider, it is of little help to check what happens inside a callback, besides
showing the response received and the output. How to debug the situation when
``parse_details`` sometimes receives no item?
.. highlight:: python
Fortunately, the :command:`shell` is your bread and butter in this case (see
:ref:`topics-shell-inspect-response`)::
from scrapy.shell import inspect_response
def parse_details(self, response):
item = response.meta.get('item', None)
def parse_details(self, response, item=None):
if item:
# populate more `item` fields
return item
@ -134,8 +140,7 @@ Logging is another useful option for getting information about your spider run.
Although not as convenient, it comes with the advantage that the logs will be
available in all future runs should they be necessary again::
def parse_details(self, response):
item = response.meta.get('item', None)
def parse_details(self, response, item=None):
if item:
# populate more `item` fields
return item

74
docs/topics/developer-tools.rst
View File

@ -39,7 +39,7 @@ Therefore, you should keep in mind the following things:
.. _topics-inspector:
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
@ -79,13 +79,23 @@ sections and tags of a webpage, which greatly improves readability. You can
expand and collapse a tag by clicking on the arrow in front of it or by double
clicking directly on the tag. If we expand the ``span`` tag with the ``class=
"text"`` we will see the quote-text we clicked on. The `Inspector` lets you
copy XPaths to selected elements. Let's try it out: Right-click on the ``span``
tag, select ``Copy > XPath`` and paste it in the scrapy shell like so::
copy XPaths to selected elements. Let's try it out.
First open the Scrapy shell at http://quotes.toscrape.com/ in a terminal:
.. code-block:: none
$ scrapy shell "http://quotes.toscrape.com/"
(...)
>>> 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.”]
Then, back to your web browser, right-click on the ``span`` tag, select
``Copy > XPath`` and paste it in the Scrapy shell like so:
.. invisible-code-block: python
response = load_response('http://quotes.toscrape.com/', 'quotes.html')
>>> 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
basic selector. But this XPath is not really that clever. All it does is
@ -112,13 +122,13 @@ 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
the `has-class-extension`_::
the `has-class-extension`_:
>>> response.xpath('//span[has-class("text")]/text()').getall()
['"The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”,
'“It is our choices, Harry, that show what we truly are, far more than our abilities.”',
'“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.”',
(...)]
>>> response.xpath('//span[has-class("text")]/text()').getall()
['“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”',
'“It is our choices, Harry, that show what we truly are, far more than our abilities.”',
'“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
@ -132,7 +142,7 @@ 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="text"``, the second the text
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
@ -159,7 +169,11 @@ 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::
we'll check another quite useful command from the Scrapy shell:
.. skip: next
.. code-block:: none
$ scrapy shell "quotes.toscrape.com/scroll"
(...)
@ -203,7 +217,7 @@ where our quotes are coming from:
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 ``Reponse``.
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
@ -252,9 +266,33 @@ 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
into our ``url``.
into our ``url``.
You can see that with a few inspections in the `Network`-tool we
.. _requests-from-curl:
In more complex websites, it could be difficult to easily reproduce the
requests, as we could need to add ``headers`` or ``cookies`` to make it work.
In those cases you can export the requests in `cURL <https://curl.haxx.se/>`_
format, by right-clicking on each of them in the network tool and using the
:meth:`~scrapy.http.Request.from_curl()` method to generate an equivalent
request::
from scrapy import Request
request = Request.from_curl(
"curl 'http://quotes.toscrape.com/api/quotes?page=1' -H 'User-Agent: Mozil"
"la/5.0 (X11; Linux x86_64; rv:67.0) Gecko/20100101 Firefox/67.0' -H 'Acce"
"pt: */*' -H 'Accept-Language: ca,en-US;q=0.7,en;q=0.3' --compressed -H 'X"
"-Requested-With: XMLHttpRequest' -H 'Proxy-Authorization: Basic QFRLLTAzM"
"zEwZTAxLTk5MWUtNDFiNC1iZWRmLTJjNGI4M2ZiNDBmNDpAVEstMDMzMTBlMDEtOTkxZS00MW"
"I0LWJlZGYtMmM0YjgzZmI0MGY0' -H 'Connection: keep-alive' -H 'Referer: http"
"://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.
As you can see, with a few inspections in the `Network`-tool we
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
@ -262,7 +300,7 @@ to identifying the correct request and replicating it in your spider.
.. _Developer Tools: https://en.wikipedia.org/wiki/Web_development_tools
.. _quotes.toscrape.com: http://quotes.toscrape.com
.. _quotes.toscrape.com/scroll: quotes.toscrape.com/scroll/
.. _quotes.toscrape.com/scroll: http://quotes.toscrape.com/scroll
.. _quotes.toscrape.com/api/quotes?page=10: http://quotes.toscrape.com/api/quotes?page=10
.. _has-class-extension: https://parsel.readthedocs.io/en/latest/usage.html#other-xpath-extensions

374
docs/topics/downloader-middleware.rst
View File

@ -52,6 +52,8 @@ as its value. For example, if you want to disable the user-agent middleware::
Finally, keep in mind that some middlewares may need to be enabled through a
particular setting. See each middleware documentation for more info.
.. _topics-downloader-middleware-custom:
Writing your own downloader middleware
======================================
@ -197,7 +199,7 @@ CookiesMiddleware
This middleware enables working with sites that require cookies, such as
those that use sessions. It keeps track of cookies sent by web servers, and
send them back on subsequent requests (from that spider), just like web
sends them back on subsequent requests (from that spider), just like web
browsers do.
The following settings can be used to configure the cookie middleware:
@ -346,10 +348,9 @@ HttpCacheMiddleware
* :ref:`httpcache-storage-fs`
* :ref:`httpcache-storage-dbm`
* :ref:`httpcache-storage-leveldb`
You can change the HTTP cache storage backend with the :setting:`HTTPCACHE_STORAGE`
setting. Or you can also implement your own storage backend.
setting. Or you can also :ref:`implement your own storage backend. <httpcache-storage-custom>`
Scrapy ships with two HTTP cache policies:
@ -363,24 +364,25 @@ HttpCacheMiddleware
You can also avoid caching a response on every policy using :reqmeta:`dont_cache` meta key equals ``True``.
.. module:: scrapy.extensions.httpcache
:noindex:
.. _httpcache-policy-dummy:
Dummy policy (default)
~~~~~~~~~~~~~~~~~~~~~~
This policy has no awareness of any HTTP Cache-Control directives.
Every request and its corresponding response are cached. When the same
request is seen again, the response is returned without transferring
anything from the Internet.
.. class:: DummyPolicy
The Dummy policy is useful for testing spiders faster (without having
to wait for downloads every time) and for trying your spider offline,
when an Internet connection is not available. The goal is to be able to
"replay" a spider run *exactly as it ran before*.
This policy has no awareness of any HTTP Cache-Control directives.
Every request and its corresponding response are cached. When the same
request is seen again, the response is returned without transferring
anything from the Internet.
In order to use this policy, set:
* :setting:`HTTPCACHE_POLICY` to ``scrapy.extensions.httpcache.DummyPolicy``
The Dummy policy is useful for testing spiders faster (without having
to wait for downloads every time) and for trying your spider offline,
when an Internet connection is not available. The goal is to be able to
"replay" a spider run *exactly as it ran before*.
.. _httpcache-policy-rfc2616:
@ -388,45 +390,44 @@ In order to use this policy, set:
RFC2616 policy
~~~~~~~~~~~~~~
This policy provides a RFC2616 compliant HTTP cache, i.e. with HTTP
Cache-Control awareness, aimed at production and used in continuous
runs to avoid downloading unmodified data (to save bandwidth and speed up crawls).
.. class:: RFC2616Policy
what is implemented:
This policy provides a RFC2616 compliant HTTP cache, i.e. with HTTP
Cache-Control awareness, aimed at production and used in continuous
runs to avoid downloading unmodified data (to save bandwidth and speed up
crawls).
* Do not attempt to store responses/requests with ``no-store`` cache-control directive set
* Do not serve responses from cache if ``no-cache`` cache-control directive is set even for fresh responses
* Compute freshness lifetime from ``max-age`` cache-control directive
* Compute freshness lifetime from ``Expires`` response header
* Compute freshness lifetime from ``Last-Modified`` response header (heuristic used by Firefox)
* Compute current age from ``Age`` response header
* Compute current age from ``Date`` header
* Revalidate stale responses based on ``Last-Modified`` response header
* Revalidate stale responses based on ``ETag`` response header
* Set ``Date`` header for any received response missing it
* Support ``max-stale`` cache-control directive in requests
What is implemented:
This allows spiders to be configured with the full RFC2616 cache policy,
but avoid revalidation on a request-by-request basis, while remaining
conformant with the HTTP spec.
* Do not attempt to store responses/requests with ``no-store`` cache-control directive set
* Do not serve responses from cache if ``no-cache`` cache-control directive is set even for fresh responses
* Compute freshness lifetime from ``max-age`` cache-control directive
* Compute freshness lifetime from ``Expires`` response header
* Compute freshness lifetime from ``Last-Modified`` response header (heuristic used by Firefox)
* Compute current age from ``Age`` response header
* Compute current age from ``Date`` header
* Revalidate stale responses based on ``Last-Modified`` response header
* Revalidate stale responses based on ``ETag`` response header
* Set ``Date`` header for any received response missing it
* Support ``max-stale`` cache-control directive in requests
Example:
This allows spiders to be configured with the full RFC2616 cache policy,
but avoid revalidation on a request-by-request basis, while remaining
conformant with the HTTP spec.
Add ``Cache-Control: max-stale=600`` to Request headers to accept responses that
have exceeded their expiration time by no more than 600 seconds.
Example:
See also: RFC2616, 14.9.3
Add ``Cache-Control: max-stale=600`` to Request headers to accept responses that
have exceeded their expiration time by no more than 600 seconds.
what is missing:
See also: RFC2616, 14.9.3
* ``Pragma: no-cache`` support https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.1
* ``Vary`` header support https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.6
* Invalidation after updates or deletes https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.10
* ... probably others ..
What is missing:
In order to use this policy, set:
* :setting:`HTTPCACHE_POLICY` to ``scrapy.extensions.httpcache.RFC2616Policy``
* ``Pragma: no-cache`` support https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.1
* ``Vary`` header support https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.6
* Invalidation after updates or deletes https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.10
* ... probably others ..
.. _httpcache-storage-fs:
@ -434,67 +435,102 @@ In order to use this policy, set:
Filesystem storage backend (default)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
File system storage backend is available for the HTTP cache middleware.
.. class:: FilesystemCacheStorage
In order to use this storage backend, set:
File system storage backend is available for the HTTP cache middleware.
* :setting:`HTTPCACHE_STORAGE` to ``scrapy.extensions.httpcache.FilesystemCacheStorage``
Each request/response pair is stored in a different directory containing
the following files:
Each request/response pair is stored in a different directory containing
the following files:
* ``request_body`` - the plain request body
* ``request_body`` - the plain request body
* ``request_headers`` - the request headers (in raw HTTP format)
* ``response_body`` - the plain response body
* ``response_headers`` - the request headers (in raw HTTP format)
* ``meta`` - some metadata of this cache resource in Python ``repr()`` format
(grep-friendly format)
* ``pickled_meta`` - the same metadata in ``meta`` but pickled for more
efficient deserialization
* ``request_headers`` - the request headers (in raw HTTP format)
The directory name is made from the request fingerprint (see
``scrapy.utils.request.fingerprint``), and one level of subdirectories is
used to avoid creating too many files into the same directory (which is
inefficient in many file systems). An example directory could be::
* ``response_body`` - the plain response body
/path/to/cache/dir/example.com/72/72811f648e718090f041317756c03adb0ada46c7
* ``response_headers`` - the request headers (in raw HTTP format)
* ``meta`` - some metadata of this cache resource in Python ``repr()``
format (grep-friendly format)
* ``pickled_meta`` - the same metadata in ``meta`` but pickled for more
efficient deserialization
The directory name is made from the request fingerprint (see
``scrapy.utils.request.fingerprint``), and one level of subdirectories is
used to avoid creating too many files into the same directory (which is
inefficient in many file systems). An example directory could be::
/path/to/cache/dir/example.com/72/72811f648e718090f041317756c03adb0ada46c7
.. _httpcache-storage-dbm:
DBM storage backend
~~~~~~~~~~~~~~~~~~~
.. versionadded:: 0.13
.. class:: DbmCacheStorage
A DBM_ storage backend is also available for the HTTP cache middleware.
.. versionadded:: 0.13
By default, it uses the anydbm_ module, but you can change it with the
:setting:`HTTPCACHE_DBM_MODULE` setting.
A DBM_ storage backend is also available for the HTTP cache middleware.
In order to use this storage backend, set:
By default, it uses the :mod:`dbm`, but you can change it with the
:setting:`HTTPCACHE_DBM_MODULE` setting.
* :setting:`HTTPCACHE_STORAGE` to ``scrapy.extensions.httpcache.DbmCacheStorage``
.. _httpcache-storage-custom:
.. _httpcache-storage-leveldb:
Writing your own storage backend
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
LevelDB storage backend
~~~~~~~~~~~~~~~~~~~~~~~
You can implement a cache storage backend by creating a Python class that
defines the methods described below.
.. versionadded:: 0.23
.. module:: scrapy.extensions.httpcache
A LevelDB_ storage backend is also available for the HTTP cache middleware.
.. class:: CacheStorage
This backend is not recommended for development because only one process can
access LevelDB databases at the same time, so you can't run a crawl and open
the scrapy shell in parallel for the same spider.
.. method:: open_spider(spider)
In order to use this storage backend:
This method gets called after a spider has been opened for crawling. It handles
the :signal:`open_spider <spider_opened>` signal.
* set :setting:`HTTPCACHE_STORAGE` to ``scrapy.extensions.httpcache.LeveldbCacheStorage``
* install `LevelDB python bindings`_ like ``pip install leveldb``
:param spider: the spider which has been opened
:type spider: :class:`~scrapy.spiders.Spider` object
.. _LevelDB: https://github.com/google/leveldb
.. _leveldb python bindings: https://pypi.python.org/pypi/leveldb
.. method:: close_spider(spider)
This method gets called after a spider has been closed. It handles
the :signal:`close_spider <spider_closed>` signal.
:param spider: the spider which has been closed
:type spider: :class:`~scrapy.spiders.Spider` object
.. method:: retrieve_response(spider, request)
Return response if present in cache, or ``None`` otherwise.
:param spider: the spider which generated the request
:type spider: :class:`~scrapy.spiders.Spider` object
:param request: the request to find cached response for
:type request: :class:`~scrapy.http.Request` object
.. method:: store_response(spider, request, response)
Store the given response in the cache.
:param spider: the spider for which the response is intended
:type spider: :class:`~scrapy.spiders.Spider` object
:param request: the corresponding request the spider generated
:type request: :class:`~scrapy.http.Request` object
:param response: the response to store in the cache
:type response: :class:`~scrapy.http.Response` object
In order to use your storage backend, set:
* :setting:`HTTPCACHE_STORAGE` to the Python import path of your custom storage class.
HTTPCache middleware settings
@ -590,7 +626,7 @@ HTTPCACHE_DBM_MODULE
.. versionadded:: 0.13
Default: ``'anydbm'``
Default: ``'dbm'``
The database module to use in the :ref:`DBM storage backend
<httpcache-storage-dbm>`. This setting is specific to the DBM backend.
@ -636,7 +672,7 @@ sometimes a more nuanced policy is desirable.
This setting still respects ``Cache-Control: no-store`` directives in responses.
If you don't want that, filter ``no-store`` out of the Cache-Control headers in
responses you feedto the cache middleware.
responses you feed to the cache middleware.
.. setting:: HTTPCACHE_IGNORE_RESPONSE_CACHE_CONTROLS
@ -650,7 +686,7 @@ Default: ``[]``
List of Cache-Control directives in responses to be ignored.
Sites often set "no-store", "no-cache", "must-revalidate", etc., but get
upset at the traffic a spider can generate if it respects those
upset at the traffic a spider can generate if it actually respects those
directives. This allows to selectively ignore Cache-Control directives
that are known to be unimportant for the sites being crawled.
@ -733,6 +769,17 @@ RedirectMiddleware
The urls which the request goes through (while being redirected) can be found
in the ``redirect_urls`` :attr:`Request.meta <scrapy.http.Request.meta>` key.
.. reqmeta:: redirect_reasons
The reason behind each redirect in :reqmeta:`redirect_urls` can be found in the
``redirect_reasons`` :attr:`Request.meta <scrapy.http.Request.meta>` key. For
example: ``[301, 302, 307, 'meta refresh']``.
The format of a reason depends on the middleware that handled the corresponding
redirect. For example, :class:`RedirectMiddleware` indicates the triggering
response status code as an integer, while :class:`MetaRefreshMiddleware`
always uses the ``'meta refresh'`` string as reason.
The :class:`RedirectMiddleware` can be configured through the following
settings (see the settings documentation for more info):
@ -794,10 +841,12 @@ The :class:`MetaRefreshMiddleware` can be configured through the following
settings (see the settings documentation for more info):
* :setting:`METAREFRESH_ENABLED`
* :setting:`METAREFRESH_IGNORE_TAGS`
* :setting:`METAREFRESH_MAXDELAY`
This middleware obey :setting:`REDIRECT_MAX_TIMES` setting, :reqmeta:`dont_redirect`
and :reqmeta:`redirect_urls` request meta keys as described for :class:`RedirectMiddleware`
This middleware obey :setting:`REDIRECT_MAX_TIMES` setting, :reqmeta:`dont_redirect`,
:reqmeta:`redirect_urls` and :reqmeta:`redirect_reasons` request meta keys as described
for :class:`RedirectMiddleware`
MetaRefreshMiddleware settings
@ -814,6 +863,15 @@ Default: ``True``
Whether the Meta Refresh middleware will be enabled.
.. setting:: METAREFRESH_IGNORE_TAGS
METAREFRESH_IGNORE_TAGS
^^^^^^^^^^^^^^^^^^^^^^^
Default: ``[]``
Meta tags within these tags are ignored.
.. setting:: METAREFRESH_MAXDELAY
METAREFRESH_MAXDELAY
@ -884,7 +942,7 @@ precedence over the :setting:`RETRY_TIMES` setting.
RETRY_HTTP_CODES
^^^^^^^^^^^^^^^^
Default: ``[500, 502, 503, 504, 522, 524, 408]``
Default: ``[500, 502, 503, 504, 522, 524, 408, 429]``
Which HTTP response codes to retry. Other errors (DNS lookup issues,
connections lost, etc) are always retried.
@ -910,6 +968,24 @@ RobotsTxtMiddleware
To make sure Scrapy respects robots.txt make sure the middleware is enabled
and the :setting:`ROBOTSTXT_OBEY` setting is enabled.
The :setting:`ROBOTSTXT_USER_AGENT` setting can be used to specify the
user agent string to use for matching in the robots.txt_ file. If it
is ``None``, the User-Agent header you are sending with the request or the
:setting:`USER_AGENT` setting (in that order) will be used for determining
the user agent to use in the robots.txt_ file.
This middleware has to be combined with a robots.txt_ parser.
Scrapy ships with support for the following robots.txt_ parsers:
* :ref:`Protego <protego-parser>` (default)
* :ref:`RobotFileParser <python-robotfileparser>`
* :ref:`Reppy <reppy-parser>`
* :ref:`Robotexclusionrulesparser <rerp-parser>`
You can change the robots.txt_ parser with the :setting:`ROBOTSTXT_PARSER`
setting. Or you can also :ref:`implement support for a new parser <support-for-new-robots-parser>`.
.. reqmeta:: dont_obey_robotstxt
If :attr:`Request.meta <scrapy.http.Request.meta>` has
@ -917,6 +993,129 @@ If :attr:`Request.meta <scrapy.http.Request.meta>` has
the request will be ignored by this middleware even if
:setting:`ROBOTSTXT_OBEY` is enabled.
Parsers vary in several aspects:
* Language of implementation
* Supported specification
* Support for wildcard matching
* Usage of `length based rule <https://developers.google.com/search/reference/robots_txt#order-of-precedence-for-group-member-lines>`_:
in particular for ``Allow`` and ``Disallow`` directives, where the most
specific rule based on the length of the path trumps the less specific
(shorter) rule
Performance comparison of different parsers is available at `the following link
<https://anubhavp28.github.io/gsoc-weekly-checkin-12/>`_.
.. _protego-parser:
Protego parser
~~~~~~~~~~~~~~
Based on `Protego <https://github.com/scrapy/protego>`_:
* implemented in Python
* is compliant with `Google's Robots.txt Specification
<https://developers.google.com/search/reference/robots_txt>`_
* supports wildcard matching
* uses the length based rule
Scrapy uses this parser by default.
.. _python-robotfileparser:
RobotFileParser
~~~~~~~~~~~~~~~
Based on `RobotFileParser
<https://docs.python.org/3.7/library/urllib.robotparser.html>`_:
* is Python's built-in robots.txt_ parser
* is compliant with `Martijn Koster's 1996 draft specification
<http://www.robotstxt.org/norobots-rfc.txt>`_
* lacks support for wildcard matching
* doesn't use the length based rule
It is faster than Protego and backward-compatible with versions of Scrapy before 1.8.0.
In order to use this parser, set:
* :setting:`ROBOTSTXT_PARSER` to ``scrapy.robotstxt.PythonRobotParser``
.. _reppy-parser:
Reppy parser
~~~~~~~~~~~~
Based on `Reppy <https://github.com/seomoz/reppy/>`_:
* is a Python wrapper around `Robots Exclusion Protocol Parser for C++
<https://github.com/seomoz/rep-cpp>`_
* is compliant with `Martijn Koster's 1996 draft specification
<http://www.robotstxt.org/norobots-rfc.txt>`_
* supports wildcard matching
* uses the length based rule
Native implementation, provides better speed than Protego.
In order to use this parser:
* Install `Reppy <https://github.com/seomoz/reppy/>`_ by running ``pip install reppy``
* Set :setting:`ROBOTSTXT_PARSER` setting to
``scrapy.robotstxt.ReppyRobotParser``
.. _rerp-parser:
Robotexclusionrulesparser
~~~~~~~~~~~~~~~~~~~~~~~~~
Based on `Robotexclusionrulesparser <http://nikitathespider.com/python/rerp/>`_:
* implemented in Python
* is compliant with `Martijn Koster's 1996 draft specification
<http://www.robotstxt.org/norobots-rfc.txt>`_
* supports wildcard matching
* doesn't use the length based rule
In order to use this parser:
* Install `Robotexclusionrulesparser <http://nikitathespider.com/python/rerp/>`_ by running
``pip install robotexclusionrulesparser``
* Set :setting:`ROBOTSTXT_PARSER` setting to
``scrapy.robotstxt.RerpRobotParser``
.. _support-for-new-robots-parser:
Implementing support for a new parser
-------------------------------------
You can implement support for a new robots.txt_ parser by subclassing
the abstract base class :class:`~scrapy.robotstxt.RobotParser` and
implementing the methods described below.
.. module:: scrapy.robotstxt
:synopsis: robots.txt parser interface and implementations
.. autoclass:: RobotParser
:members:
.. _robots.txt: http://www.robotstxt.org/
DownloaderStats
---------------
@ -1003,4 +1202,3 @@ The default encoding for proxy authentication on :class:`HttpProxyMiddleware`.
.. _DBM: https://en.wikipedia.org/wiki/Dbm
.. _anydbm: https://docs.python.org/2/library/anydbm.html

253
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@ -0,0 +1,253 @@
.. _topics-dynamic-content:
====================================
Selecting dynamically-loaded content
====================================
Some webpages show the desired data when you load them in a web browser.
However, when you download them using Scrapy, you cannot reach the desired data
using :ref:`selectors <topics-selectors>`.
When this happens, the recommended approach is to
:ref:`find the data source <topics-finding-data-source>` and extract the data
from it.
If you fail to do that, and you can nonetheless access the desired data through
the :ref:`DOM <topics-livedom>` from your web browser, see
:ref:`topics-javascript-rendering`.
.. _topics-finding-data-source:
Finding the data source
=======================
To extract the desired data, you must first find its source location.
If the data is in a non-text-based format, such as an image or a PDF document,
use the :ref:`network tool <topics-network-tool>` of your web browser to find
the corresponding request, and :ref:`reproduce it
<topics-reproducing-requests>`.
If your web browser lets you select the desired data as text, the data may be
defined in embedded JavaScript code, or loaded from an external resource in a
text-based format.
In that case, you can use a tool like wgrep_ to find the URL of that resource.
If the data turns out to come from the original URL itself, you must
:ref:`inspect the source code of the webpage <topics-inspecting-source>` to
determine where the data is located.
If the data comes from a different URL, you will need to :ref:`reproduce the
corresponding request <topics-reproducing-requests>`.
.. _topics-inspecting-source:
Inspecting the source code of a webpage
=======================================
Sometimes you need to inspect the source code of a webpage (not the
:ref:`DOM <topics-livedom>`) to determine where some desired data is located.
Use Scrapy’s :command:`fetch` command to download the webpage contents as seen
by Scrapy::
scrapy fetch --nolog https://example.com > response.html
If the desired data is in embedded JavaScript code within a ``<script/>``
element, see :ref:`topics-parsing-javascript`.
If you cannot find the desired data, first make sure it’s not just Scrapy:
download the webpage with an HTTP client like curl_ or wget_ and see if the
information can be found in the response they get.
If they get a response with the desired data, modify your Scrapy
:class:`~scrapy.http.Request` to match that of the other HTTP client. For
example, try using the same user-agent string (:setting:`USER_AGENT`) or the
same :attr:`~scrapy.http.Request.headers`.
If they also get a response without the desired data, you’ll need to take
steps to make your request more similar to that of the web browser. See
:ref:`topics-reproducing-requests`.
.. _topics-reproducing-requests:
Reproducing requests
====================
Sometimes we need to reproduce a request the way our web browser performs it.
Use the :ref:`network tool <topics-network-tool>` of your web browser to see
how your web browser performs the desired request, and try to reproduce that
request with Scrapy.
It might be enough to yield a :class:`~scrapy.http.Request` with the same HTTP
method and URL. However, you may also need to reproduce the body, headers and
form parameters (see :class:`~scrapy.http.FormRequest`) of that request.
As all major browsers allow to export the requests in `cURL
<https://curl.haxx.se/>`_ format, Scrapy incorporates the method
:meth:`~scrapy.http.Request.from_curl()` to generate an equivalent
:class:`~scrapy.http.Request` from a cURL command. To get more information
visit :ref:`request from curl <requests-from-curl>` inside the network
tool section.
Once you get the expected response, you can :ref:`extract the desired data from
it <topics-handling-response-formats>`.
You can reproduce any request with Scrapy. However, some times reproducing all
necessary requests may not seem efficient in developer time. If that is your
case, and crawling speed is not a major concern for you, you can alternatively
consider :ref:`JavaScript pre-rendering <topics-javascript-rendering>`.
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.
.. _topics-handling-response-formats:
Handling different response formats
===================================
Once you have a response with the desired data, how you extract the desired
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
:attr:`response.text <scrapy.http.TextResponse.text>`::
data = json.loads(response.text)
If the desired data is inside HTML or XML code embedded within JSON data,
you can load that HTML or XML code into a
:class:`~scrapy.selector.Selector` and then
:ref:`use it <topics-selectors>` as usual::
selector = Selector(data['html'])
- 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>`.
.. _topics-parsing-images:
- If the response is an image or another format based on images (e.g. PDF),
read the response as bytes from
:attr:`response.body <scrapy.http.TextResponse.body>` and use an OCR
solution to extract the desired data as text.
For example, you can use pytesseract_. To read a table from a PDF,
`tabula-py`_ may be a better choice.
- If the response is SVG, or HTML with embedded SVG containing the desired
data, you may be able to extract the desired data using
:ref:`selectors <topics-selectors>`, since SVG is based on XML.
Otherwise, you might need to convert the SVG code into a raster image, and
:ref:`handle that raster image <topics-parsing-images>`.
.. _topics-parsing-javascript:
Parsing JavaScript code
=======================
If the desired data is hardcoded in JavaScript, you first need to get the
JavaScript code:
- If the JavaScript code is in a JavaScript file, simply read
:attr:`response.text <scrapy.http.TextResponse.text>`.
- If the JavaScript code is within a ``<script/>`` element of an HTML page,
use :ref:`selectors <topics-selectors>` to extract the text within that
``<script/>`` element.
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`_.
For example, if the JavaScript code contains a separate line like
``var data = {"field": "value"};`` you can extract that data as follows:
>>> pattern = r'\bvar\s+data\s*=\s*(\{.*?\})\s*;\s*\n'
>>> json_data = response.css('script::text').re_first(pattern)
>>> json.loads(json_data)
{'field': 'value'}
- Otherwise, use js2xml_ to convert the JavaScript code into an XML document
that you can parse using :ref:`selectors <topics-selectors>`.
For example, if the JavaScript code contains
``var data = {field: "value"};`` you can extract that data as follows:
>>> import js2xml
>>> import lxml.etree
>>> from parsel import Selector
>>> javascript = response.css('script::text').get()
>>> xml = lxml.etree.tostring(js2xml.parse(javascript), encoding='unicode')
>>> selector = Selector(text=xml)
>>> selector.css('var[name="data"]').get()
'<var name="data"><object><property name="field"><string>value</string></property></object></var>'
.. _topics-javascript-rendering:
Pre-rendering JavaScript
========================
On webpages that fetch data from additional requests, reproducing those
requests that contain the desired data is the preferred approach. The effort is
often worth the result: structured, complete data with minimum parsing time and
network transfer.
However, sometimes it can be really hard to reproduce certain requests. Or you
may need something that no request can give you, such as a screenshot of a
webpage as seen in a web browser.
In these cases use the Splash_ JavaScript-rendering service, along with
`scrapy-splash`_ for seamless integration.
Splash returns as HTML the :ref:`DOM <topics-livedom>` of a webpage, so that
you can parse it with :ref:`selectors <topics-selectors>`. It provides great
flexibility through configuration_ or scripting_.
If you need something beyond what Splash offers, such as interacting with the
DOM on-the-fly from Python code instead of using a previously-written script,
or handling multiple web browser windows, you might need to
:ref:`use a headless browser <topics-headless-browsing>` instead.
.. _configuration: https://splash.readthedocs.io/en/stable/api.html
.. _scripting: https://splash.readthedocs.io/en/stable/scripting-tutorial.html
.. _topics-headless-browsing:
Using a headless browser
========================
A `headless browser`_ is a special web browser that provides an API for
automation.
The easiest way to use a headless browser with Scrapy is to use Selenium_,
along with `scrapy-selenium`_ for seamless integration.
.. _AJAX: https://en.wikipedia.org/wiki/Ajax_%28programming%29
.. _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/library/json.html#json.loads
.. _pytesseract: https://github.com/madmaze/pytesseract
.. _regular expression: https://docs.python.org/library/re.html
.. _scrapy-selenium: https://github.com/clemfromspace/scrapy-selenium
.. _scrapy-splash: https://github.com/scrapy-plugins/scrapy-splash
.. _Selenium: https://www.seleniumhq.org/
.. _Splash: https://github.com/scrapinghub/splash
.. _tabula-py: https://github.com/chezou/tabula-py
.. _wget: https://www.gnu.org/software/wget/
.. _wgrep: https://github.com/stav/wgrep

17
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@ -9,19 +9,19 @@ Sending e-mail
Although Python makes sending e-mails relatively easy via the `smtplib`_
library, Scrapy provides its own facility for sending e-mails which is very
easy to use and it's implemented using `Twisted non-blocking IO`_, to avoid
interfering with the non-blocking 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>`.
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
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
.. _Twisted non-blocking IO: https://twistedmatrix.com/documents/current/core/howto/defer-intro.html
Quick example
=============
There are two ways to instantiate the mail sender. You can instantiate it using
the standard constructor::
the standard ``__init__`` method::
from scrapy.mail import MailSender
mailer = MailSender()
@ -39,7 +39,8 @@ MailSender class reference
==========================
MailSender is the preferred class to use for sending emails from Scrapy, as it
uses `Twisted non-blocking IO`_, like the rest of the framework.
uses :doc:`Twisted non-blocking IO <twisted:core/howto/defer-intro>`, like the
rest of the framework.
.. class:: MailSender(smtphost=None, mailfrom=None, smtpuser=None, smtppass=None, smtpport=None)
@ -111,7 +112,7 @@ uses `Twisted non-blocking IO`_, like the rest of the framework.
Mail settings
=============
These settings define the default constructor values of the :class:`MailSender`
These settings define the default ``__init__`` method values of the :class:`MailSender`
class, and can be used to configure e-mail notifications in your project without
writing any code (for those extensions and code that uses :class:`MailSender`).

56
docs/topics/exporters.rst
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@ -51,7 +51,6 @@ value of one of their fields::
def close_spider(self, spider):
for exporter in self.year_to_exporter.values():
exporter.finish_exporting()
exporter.file.close()
def _exporter_for_item(self, item):
year = item['year']
@ -88,8 +87,8 @@ described next.
1. Declaring a serializer in the field
--------------------------------------
If you use :class:`~.Item` you can declare a serializer in the
:ref:`field metadata <topics-items-fields>`. The serializer must be
If you use :class:`~.Item` you can declare a serializer in the
:ref:`field metadata <topics-items-fields>`. The serializer must be
a callable which receives a value and returns its serialized form.
Example::
@ -145,7 +144,7 @@ BaseItemExporter
defining what fields to export, whether to export empty fields, or which
encoding to use.
These features can be configured through the constructor arguments which
These features can be configured through the ``__init__`` method arguments which
populate their respective instance attributes: :attr:`fields_to_export`,
:attr:`export_empty_fields`, :attr:`encoding`, :attr:`indent`.
@ -165,9 +164,9 @@ BaseItemExporter
value unchanged except for ``unicode`` values which are encoded to
``str`` using the encoding declared in the :attr:`encoding` attribute.
:param field: the field being serialized. If a raw dict is being
: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
:type field: :class:`~scrapy.item.Field` object or an empty dict
:param name: the name of the field being serialized
:type name: str
@ -223,6 +222,12 @@ BaseItemExporter
* ``indent<=0`` each item on its own line, no indentation
* ``indent>0`` each item on its own line, indented with the provided numeric value
PythonItemExporter
------------------
.. autoclass:: PythonItemExporter
.. highlight:: none
XmlItemExporter
@ -241,8 +246,8 @@ XmlItemExporter
:param item_element: The name of each item element in the exported XML.
:type item_element: str
The additional keyword arguments of this constructor are passed to the
:class:`BaseItemExporter` constructor.
The additional keyword arguments of this ``__init__`` method are passed to the
:class:`BaseItemExporter` ``__init__`` method.
A typical output of this exporter would be::
@ -301,9 +306,9 @@ CsvItemExporter
multi-valued fields, if found.
:type include_headers_line: str
The additional keyword arguments of this constructor are passed to the
:class:`BaseItemExporter` constructor, and the leftover arguments to the
`csv.writer`_ constructor, so you can use any ``csv.writer`` constructor
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
argument to customize this exporter.
A typical output of this exporter would be::
@ -329,8 +334,8 @@ PickleItemExporter
For more information, refer to the `pickle module documentation`_.
The additional keyword arguments of this constructor are passed to the
:class:`BaseItemExporter` constructor.
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.
@ -346,8 +351,8 @@ PprintItemExporter
: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)
The additional keyword arguments of this constructor are passed to the
:class:`BaseItemExporter` constructor.
The additional keyword arguments of this ``__init__`` method are passed to the
:class:`BaseItemExporter` ``__init__`` method.
A typical output of this exporter would be::
@ -362,10 +367,10 @@ JsonItemExporter
.. class:: JsonItemExporter(file, \**kwargs)
Exports Items in JSON format to the specified file-like object, writing all
objects as a list of objects. The additional constructor arguments are
passed to the :class:`BaseItemExporter` constructor, and the leftover
arguments to the `JSONEncoder`_ constructor, so you can use any
`JSONEncoder`_ constructor argument to customize this exporter.
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.
: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)
@ -393,10 +398,10 @@ JsonLinesItemExporter
.. class:: JsonLinesItemExporter(file, \**kwargs)
Exports Items in JSON format to the specified file-like object, writing one
JSON-encoded item per line. The additional constructor arguments are passed
to the :class:`BaseItemExporter` constructor, and the leftover arguments to
the `JSONEncoder`_ constructor, so you can use any `JSONEncoder`_
constructor argument to customize this exporter.
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.
: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)
@ -410,3 +415,8 @@ JsonLinesItemExporter
this exporter is well suited for serializing large amounts of data.
.. _JSONEncoder: https://docs.python.org/2/library/json.html#json.JSONEncoder
MarshalItemExporter
-------------------
.. autoclass:: MarshalItemExporter

16
docs/topics/extensions.rst
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@ -28,7 +28,7 @@ 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 constructor (``__init__`` method).
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
@ -183,7 +183,7 @@ Telnet console extension
.. module:: scrapy.extensions.telnet
:synopsis: Telnet console
.. class:: scrapy.extensions.telnet.TelnetConsole
.. class:: TelnetConsole
Provides a telnet console for getting into a Python interpreter inside the
currently running Scrapy process, which can be very useful for debugging.
@ -200,7 +200,7 @@ Memory usage extension
.. module:: scrapy.extensions.memusage
:synopsis: Memory usage extension
.. class:: scrapy.extensions.memusage.MemoryUsage
.. class:: MemoryUsage
.. note:: This extension does not work in Windows.
@ -228,7 +228,7 @@ Memory debugger extension
.. module:: scrapy.extensions.memdebug
:synopsis: Memory debugger extension
.. class:: scrapy.extensions.memdebug.MemoryDebugger
.. class:: MemoryDebugger
An extension for debugging memory usage. It collects information about:
@ -244,7 +244,7 @@ Close spider extension
.. module:: scrapy.extensions.closespider
:synopsis: Close spider extension
.. class:: scrapy.extensions.closespider.CloseSpider
.. class:: CloseSpider
Closes a spider automatically when some conditions are met, using a specific
closing reason for each condition.
@ -317,7 +317,7 @@ StatsMailer extension
.. module:: scrapy.extensions.statsmailer
:synopsis: StatsMailer extension
.. class:: scrapy.extensions.statsmailer.StatsMailer
.. class:: StatsMailer
This simple extension can be used to send a notification e-mail every time a
domain has finished scraping, including the Scrapy stats collected. The email
@ -333,7 +333,7 @@ Debugging extensions
Stack trace dump extension
~~~~~~~~~~~~~~~~~~~~~~~~~~
.. class:: scrapy.extensions.debug.StackTraceDump
.. class:: StackTraceDump
Dumps information about the running process when a `SIGQUIT`_ or `SIGUSR2`_
signal is received. The information dumped is the following:
@ -362,7 +362,7 @@ There are at least two ways to send Scrapy the `SIGQUIT`_ signal:
Debugger extension
~~~~~~~~~~~~~~~~~~
.. class:: scrapy.extensions.debug.Debugger
.. class:: Debugger
Invokes a `Python debugger`_ inside a running Scrapy process when a `SIGUSR2`_
signal is received. After the debugger is exited, the Scrapy process continues

26
docs/topics/feed-exports.rst
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@ -99,12 +99,12 @@ 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_ or boto_)
* :ref:`topics-feed-storage-s3` (requires botocore_)
* :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_
or boto_ library is installed (Scrapy supports boto_ only on Python 2).
library is installed.
.. _topics-feed-uri-params:
@ -164,6 +164,11 @@ The feeds are stored in a FTP server.
* 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``.
.. _topics-feed-storage-s3:
S3
@ -177,7 +182,7 @@ The feeds are stored on `Amazon S3`_.
* ``s3://mybucket/path/to/export.csv``
* ``s3://aws_key:aws_secret@mybucket/path/to/export.csv``
* Required external libraries: `botocore`_ (Python 2 and Python 3) or `boto`_ (Python 2 only)
* Required external libraries: `botocore`_
The AWS credentials can be passed as user/password in the URI, or they can be
passed through the following settings:
@ -230,6 +235,7 @@ These are the settings used for configuring the feed exports:
* :setting:`FEED_URI` (mandatory)
* :setting:`FEED_FORMAT`
* :setting:`FEED_STORAGES`
* :setting:`FEED_STORAGE_FTP_ACTIVE`
* :setting:`FEED_STORAGE_S3_ACL`
* :setting:`FEED_EXPORTERS`
* :setting:`FEED_STORE_EMPTY`
@ -328,6 +334,19 @@ Default: ``{}``
A dict containing additional feed storage backends supported by your project.
The keys are URI schemes and the values are paths to storage classes.
.. setting:: FEED_STORAGE_FTP_ACTIVE
FEED_STORAGE_FTP_ACTIVE
-----------------------
Default: ``False``
Whether to use the active connection mode when exporting feeds to an FTP server
(``True``) or use the passive connection mode instead (``False``, default).
For information about FTP connection modes, see `What is the difference between
active and passive FTP? <https://stackoverflow.com/a/1699163>`_.
.. setting:: FEED_STORAGE_S3_ACL
FEED_STORAGE_S3_ACL
@ -401,7 +420,6 @@ format in :setting:`FEED_EXPORTERS`. E.g., to disable the built-in CSV exporter
.. _URI: https://en.wikipedia.org/wiki/Uniform_Resource_Identifier
.. _Amazon S3: https://aws.amazon.com/s3/
.. _boto: https://github.com/boto/boto
.. _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/

9
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@ -29,7 +29,8 @@ Each item pipeline component is a Python class that must implement the following
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 `Twisted Deferred`_ or raise
(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.
@ -67,8 +68,6 @@ Additionally, they may also implement the following methods:
:type crawler: :class:`~scrapy.crawler.Crawler` object
.. _Twisted Deferred: https://twistedmatrix.com/documents/current/core/howto/defer.html
Item pipeline example
=====================
@ -166,7 +165,8 @@ method and how to clean up the resources properly.::
Take screenshot of item
-----------------------
This example demonstrates how to return Deferred_ from :meth:`process_item` method.
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
and Deferred callback fires, it saves item to a file and adds filename to an item.
@ -209,7 +209,6 @@ and Deferred callback fires, it saves item to a file and adds filename to an ite
return item
.. _Splash: https://splash.readthedocs.io/en/stable/
.. _Deferred: https://twistedmatrix.com/documents/current/core/howto/defer.html
Duplicates filter
-----------------

128
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@ -16,12 +16,12 @@ especially in a larger project with many spiders.
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.
their available fields.
Various Scrapy components use extra information provided by Items:
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
tracks Item instances to help find memory leaks
(see :ref:`topics-leaks-trackrefs`), etc.
.. _dictionary-like: https://docs.python.org/2/library/stdtypes.html#dict
@ -84,79 +84,78 @@ notice the API is very similar to the `dict API`_.
Creating items
--------------
::
>>> product = Product(name='Desktop PC', price=1000)
>>> print(product)
Product(name='Desktop PC', price=1000)
>>> product = Product(name='Desktop PC', price=1000)
>>> print(product)
Product(name='Desktop PC', price=1000)
Getting field values
--------------------
::
>>> product['name']
Desktop PC
>>> product.get('name')
Desktop PC
>>> product['name']
Desktop PC
>>> product.get('name')
Desktop PC
>>> product['price']
1000
>>> product['price']
1000
>>> product['last_updated']
Traceback (most recent call last):
...
KeyError: 'last_updated'
>>> product['last_updated']
Traceback (most recent call last):
...
KeyError: 'last_updated'
>>> product.get('last_updated', 'not set')
not set
>>> product.get('last_updated', 'not set')
not set
>>> product['lala'] # getting unknown field
Traceback (most recent call last):
...
KeyError: 'lala'
>>> product['lala'] # getting unknown field
Traceback (most recent call last):
...
KeyError: 'lala'
>>> product.get('lala', 'unknown field')
'unknown field'
>>> product.get('lala', 'unknown field')
'unknown field'
>>> 'name' in product # is name field populated?
True
>>> 'name' in product # is name field populated?
True
>>> 'last_updated' in product # is last_updated populated?
False
>>> 'last_updated' in product # is last_updated populated?
False
>>> 'last_updated' in product.fields # is last_updated a declared field?
True
>>> 'last_updated' in product.fields # is last_updated a declared field?
True
>>> 'lala' in product.fields # is lala a declared field?
False
>>> 'lala' in product.fields # is lala a declared field?
False
Setting field values
--------------------
::
>>> product['last_updated'] = 'today'
>>> product['last_updated']
today
>>> product['last_updated'] = 'today'
>>> product['last_updated']
today
>>> product['lala'] = 'test' # setting unknown field
Traceback (most recent call last):
...
KeyError: 'Product does not support field: lala'
>>> product['lala'] = 'test' # setting unknown field
Traceback (most recent call last):
...
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 `dict API`_:
>>> product.keys()
['price', 'name']
>>> product.keys()
['price', 'name']
>>> product.items()
[('price', 1000), ('name', 'Desktop PC')]
>>> product.items()
[('price', 1000), ('name', 'Desktop PC')]
.. _copying-items:
Copying items
-------------
@ -192,20 +191,21 @@ To create a deep copy, call :meth:`~scrapy.item.Item.deepcopy` instead
Other common tasks
------------------
Creating dicts from items::
Creating dicts from items:
>>> dict(product) # create a dict from all populated values
{'price': 1000, 'name': 'Desktop PC'}
>>> dict(product) # create a dict from all populated values
{'price': 1000, 'name': 'Desktop PC'}
Creating items from dicts::
Creating items from dicts:
>>> Product({'name': 'Laptop PC', 'price': 1500})
Product(price=1500, name='Laptop PC')
>>> Product({'name': 'Laptop PC', 'price': 1500})
Product(price=1500, name='Laptop PC')
>>> Product({'name': 'Laptop PC', 'lala': 1500}) # warning: unknown field in dict
Traceback (most recent call last):
...
KeyError: 'Product does not support field: lala'
>>> Product({'name': 'Laptop PC', 'lala': 1500}) # warning: unknown field in dict
Traceback (most recent call last):
...
KeyError: 'Product does not support field: lala'
Extending Items
===============
@ -235,8 +235,12 @@ Item objects
Return a new Item optionally initialized from the given argument.
Items replicate the standard `dict API`_, including its constructor. The
only additional attribute provided by Items is:
Items replicate the standard `dict API`_, including its ``__init__`` method, and
also provide the following additional API members:
.. automethod:: copy
.. automethod:: deepcopy
.. attribute:: fields
@ -261,3 +265,9 @@ Field objects
.. _dict: https://docs.python.org/2/library/stdtypes.html#dict
Other classes related to Item
=============================
.. autoclass:: BaseItem
.. autoclass:: ItemMeta

30
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@ -71,33 +71,11 @@ on cookies.
Request serialization
---------------------
Requests must be serializable by the ``pickle`` module, in order for persistence
to work, so you should make sure that your requests are serializable.
The most common issue here is to use ``lambda`` functions on request callbacks that
can't be persisted.
So, for example, this won't work::
def some_callback(self, response):
somearg = 'test'
return scrapy.Request('http://www.example.com', callback=lambda r: self.other_callback(r, somearg))
def other_callback(self, response, somearg):
print("the argument passed is: %s" % somearg)
But this will::
def some_callback(self, response):
somearg = 'test'
return scrapy.Request('http://www.example.com', callback=self.other_callback, meta={'somearg': somearg})
def other_callback(self, response):
somearg = response.meta['somearg']
print("the argument passed is: %s" % somearg)
For persistence to work, :class:`~scrapy.http.Request` objects must be
serializable with :mod:`pickle`, except for the ``callback`` and ``errback``
values passed to their ``__init__`` method, which must be methods of the
running :class:`~scrapy.spiders.Spider` class.
If you wish to log the requests that couldn't be serialized, you can set the
:setting:`SCHEDULER_DEBUG` setting to ``True`` in the project's settings page.
It is ``False`` by default.
.. _pickle: https://docs.python.org/library/pickle.html

158
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@ -27,10 +27,11 @@ Common causes of memory leaks
It happens quite often (sometimes by accident, sometimes on purpose) that the
Scrapy developer passes objects referenced in Requests (for example, using the
:attr:`~scrapy.http.Request.meta` attribute or the request callback function)
and that effectively bounds the lifetime of those referenced objects to the
lifetime of the Request. This is, by far, the most common cause of memory leaks
in Scrapy projects, and a quite difficult one to debug for newcomers.
:attr:`~scrapy.http.Request.cb_kwargs` or :attr:`~scrapy.http.Request.meta`
attributes or the request callback function) and that effectively bounds the
lifetime of those referenced objects to the lifetime of the Request. This is,
by far, the most common cause of memory leaks in Scrapy projects, and a quite
difficult one to debug for newcomers.
In big projects, the spiders are typically written by different people and some
of those spiders could be "leaking" and thus affecting the rest of the other
@ -48,7 +49,8 @@ Too Many Requests?
By default Scrapy keeps the request queue in memory; it includes
:class:`~scrapy.http.Request` objects and all objects
referenced in Request attributes (e.g. in :attr:`~scrapy.http.Request.meta`).
referenced in Request attributes (e.g. in :attr:`~scrapy.http.Request.cb_kwargs`
and :attr:`~scrapy.http.Request.meta`).
While not necessarily a leak, this can take a lot of memory. Enabling
:ref:`persistent job queue <topics-jobs>` could help keeping memory usage
in control.
@ -101,14 +103,14 @@ 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,
callback=self.parse, meta={referer: response})
callback=self.parse, cb_kwargs={'referer': response})
That line is passing a response reference inside a request which effectively
ties the response lifetime to the requests' one, and that would definitely
cause memory leaks.
Let's see how we can discover the cause (without knowing it
a-priori, of course) by using the ``trackref`` tool.
a priori, of course) by using the ``trackref`` tool.
After the crawler is running for a few minutes and we notice its memory usage
has grown a lot, we can enter its telnet console and check the live
@ -130,21 +132,21 @@ and check the code of the spider to discover the nasty line that is
generating the leaks (passing response references inside requests).
Sometimes extra information about live objects can be helpful.
Let's check the oldest response::
Let's check the oldest response:
>>> from scrapy.utils.trackref import get_oldest
>>> r = get_oldest('HtmlResponse')
>>> r.url
'http://www.somenastyspider.com/product.php?pid=123'
>>> from scrapy.utils.trackref import get_oldest
>>> r = get_oldest('HtmlResponse')
>>> r.url
'http://www.somenastyspider.com/product.php?pid=123'
If you want to iterate over all objects, instead of getting the oldest one, you
can use the :func:`scrapy.utils.trackref.iter_all` function::
can use the :func:`scrapy.utils.trackref.iter_all` function:
>>> from scrapy.utils.trackref import iter_all
>>> [r.url for r in iter_all('HtmlResponse')]
['http://www.somenastyspider.com/product.php?pid=123',
'http://www.somenastyspider.com/product.php?pid=584',
...
>>> from scrapy.utils.trackref import iter_all
>>> [r.url for r in iter_all('HtmlResponse')]
['http://www.somenastyspider.com/product.php?pid=123',
'http://www.somenastyspider.com/product.php?pid=584',
...]
Too many spiders?
-----------------
@ -153,10 +155,10 @@ If your project has too many spiders executed in parallel,
the output of :func:`prefs()` can be difficult to read.
For this reason, that function has a ``ignore`` argument which can be used to
ignore a particular class (and all its subclases). For
example, this won't show any live references to spiders::
example, this won't show any live references to spiders:
>>> from scrapy.spiders import Spider
>>> prefs(ignore=Spider)
>>> from scrapy.spiders import Spider
>>> prefs(ignore=Spider)
.. module:: scrapy.utils.trackref
:synopsis: Track references of live objects
@ -212,41 +214,41 @@ If you use ``pip``, you can install Guppy with the following command::
The telnet console also comes with a built-in shortcut (``hpy``) for accessing
Guppy heap objects. Here's an example to view all Python objects available in
the heap using Guppy::
the heap using Guppy:
>>> x = hpy.heap()
>>> x.bytype
Partition of a set of 297033 objects. Total size = 52587824 bytes.
Index Count % Size % Cumulative % Type
0 22307 8 16423880 31 16423880 31 dict
1 122285 41 12441544 24 28865424 55 str
2 68346 23 5966696 11 34832120 66 tuple
3 227 0 5836528 11 40668648 77 unicode
4 2461 1 2222272 4 42890920 82 type
5 16870 6 2024400 4 44915320 85 function
6 13949 5 1673880 3 46589200 89 types.CodeType
7 13422 5 1653104 3 48242304 92 list
8 3735 1 1173680 2 49415984 94 _sre.SRE_Pattern
9 1209 0 456936 1 49872920 95 scrapy.http.headers.Headers
<1676 more rows. Type e.g. '_.more' to view.>
>>> x = hpy.heap()
>>> x.bytype
Partition of a set of 297033 objects. Total size = 52587824 bytes.
Index Count % Size % Cumulative % Type
0 22307 8 16423880 31 16423880 31 dict
1 122285 41 12441544 24 28865424 55 str
2 68346 23 5966696 11 34832120 66 tuple
3 227 0 5836528 11 40668648 77 unicode
4 2461 1 2222272 4 42890920 82 type
5 16870 6 2024400 4 44915320 85 function
6 13949 5 1673880 3 46589200 89 types.CodeType
7 13422 5 1653104 3 48242304 92 list
8 3735 1 1173680 2 49415984 94 _sre.SRE_Pattern
9 1209 0 456936 1 49872920 95 scrapy.http.headers.Headers
<1676 more rows. Type e.g. '_.more' to view.>
You can see that most space is used by dicts. Then, if you want to see from
which attribute those dicts are referenced, you could do::
which attribute those dicts are referenced, you could do:
>>> x.bytype[0].byvia
Partition of a set of 22307 objects. Total size = 16423880 bytes.
Index Count % Size % Cumulative % Referred Via:
0 10982 49 9416336 57 9416336 57 '.__dict__'
1 1820 8 2681504 16 12097840 74 '.__dict__', '.func_globals'
2 3097 14 1122904 7 13220744 80
3 990 4 277200 2 13497944 82 "['cookies']"
4 987 4 276360 2 13774304 84 "['cache']"
5 985 4 275800 2 14050104 86 "['meta']"
6 897 4 251160 2 14301264 87 '[2]'
7 1 0 196888 1 14498152 88 "['moduleDict']", "['modules']"
8 672 3 188160 1 14686312 89 "['cb_kwargs']"
9 27 0 155016 1 14841328 90 '[1]'
<333 more rows. Type e.g. '_.more' to view.>
>>> x.bytype[0].byvia
Partition of a set of 22307 objects. Total size = 16423880 bytes.
Index Count % Size % Cumulative % Referred Via:
0 10982 49 9416336 57 9416336 57 '.__dict__'
1 1820 8 2681504 16 12097840 74 '.__dict__', '.func_globals'
2 3097 14 1122904 7 13220744 80
3 990 4 277200 2 13497944 82 "['cookies']"
4 987 4 276360 2 13774304 84 "['cache']"
5 985 4 275800 2 14050104 86 "['meta']"
6 897 4 251160 2 14301264 87 '[2]'
7 1 0 196888 1 14498152 88 "['moduleDict']", "['modules']"
8 672 3 188160 1 14686312 89 "['cb_kwargs']"
9 27 0 155016 1 14841328 90 '[1]'
<333 more rows. Type e.g. '_.more' to view.>
As you can see, the Guppy module is very powerful but also requires some deep
knowledge about Python internals. For more info about Guppy, refer to the
@ -258,7 +260,7 @@ knowledge about Python internals. For more info about Guppy, refer to the
Debugging memory leaks with muppy
=================================
If you're using Python 3, you can use muppy from `Pympler`_.
You can use muppy from `Pympler`_.
.. _Pympler: https://pypi.org/project/Pympler/
@ -267,32 +269,32 @@ If you use ``pip``, you can install muppy with the following command::
pip install Pympler
Here's an example to view all Python objects available in
the heap using muppy::
the heap using muppy:
>>> from pympler import muppy
>>> all_objects = muppy.get_objects()
>>> len(all_objects)
28667
>>> from pympler import summary
>>> suml = summary.summarize(all_objects)
>>> summary.print_(suml)
types | # objects | total size
==================================== | =========== | ============
<class 'str | 9822 | 1.10 MB
<class 'dict | 1658 | 856.62 KB
<class 'type | 436 | 443.60 KB
<class 'code | 2974 | 419.56 KB
<class '_io.BufferedWriter | 2 | 256.34 KB
<class 'set | 420 | 159.88 KB
<class '_io.BufferedReader | 1 | 128.17 KB
<class 'wrapper_descriptor | 1130 | 88.28 KB
<class 'tuple | 1304 | 86.57 KB
<class 'weakref | 1013 | 79.14 KB
<class 'builtin_function_or_method | 958 | 67.36 KB
<class 'method_descriptor | 865 | 60.82 KB
<class 'abc.ABCMeta | 62 | 59.96 KB
<class 'list | 446 | 58.52 KB
<class 'int | 1425 | 43.20 KB
>>> from pympler import muppy
>>> all_objects = muppy.get_objects()
>>> len(all_objects)
28667
>>> from pympler import summary
>>> suml = summary.summarize(all_objects)
>>> summary.print_(suml)
types | # objects | total size
==================================== | =========== | ============
<class 'str | 9822 | 1.10 MB
<class 'dict | 1658 | 856.62 KB
<class 'type | 436 | 443.60 KB
<class 'code | 2974 | 419.56 KB
<class '_io.BufferedWriter | 2 | 256.34 KB
<class 'set | 420 | 159.88 KB
<class '_io.BufferedReader | 1 | 128.17 KB
<class 'wrapper_descriptor | 1130 | 88.28 KB
<class 'tuple | 1304 | 86.57 KB
<class 'weakref | 1013 | 79.14 KB
<class 'builtin_function_or_method | 958 | 67.36 KB
<class 'method_descriptor | 865 | 60.82 KB
<class 'abc.ABCMeta | 62 | 59.96 KB
<class 'list | 446 | 58.52 KB
<class 'int | 1425 | 43.20 KB
For more info about muppy, refer to the `muppy documentation`_.

45
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@ -4,46 +4,33 @@
Link Extractors
===============
Link extractors are objects whose only purpose is to extract links from web
pages (:class:`scrapy.http.Response` objects) which will be eventually
followed.
A link extractor is an object that extracts links from responses.
There is ``scrapy.linkextractors.LinkExtractor`` available
in Scrapy, but you can create your own custom Link Extractors to suit your
needs by implementing a simple interface.
The only public method that every link extractor has is ``extract_links``,
which receives a :class:`~scrapy.http.Response` object and returns a list
of :class:`scrapy.link.Link` objects. Link extractors are meant to be
instantiated once and their ``extract_links`` method called several times
with different responses to extract links to follow.
Link extractors are used in the :class:`~scrapy.spiders.CrawlSpider`
class (available in Scrapy), through a set of rules, but you can also use it in
your spiders, even if you don't subclass from
:class:`~scrapy.spiders.CrawlSpider`, as its purpose is very simple: to
extract links.
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
: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.
.. _topics-link-extractors-ref:
Built-in link extractors reference
==================================
Link extractor reference
========================
.. module:: scrapy.linkextractors
:synopsis: Link extractors classes
Link extractors classes bundled with Scrapy are provided in the
:mod:`scrapy.linkextractors` module.
The default link extractor is ``LinkExtractor``, which is the same as
:class:`~.LxmlLinkExtractor`::
The link extractor class is
:class:`scrapy.linkextractors.lxmlhtml.LxmlLinkExtractor`. For convenience it
can also be imported as ``scrapy.linkextractors.LinkExtractor``::
from scrapy.linkextractors import LinkExtractor
There used to be other link extractor classes in previous Scrapy versions,
but they are deprecated now.
LxmlLinkExtractor
-----------------
@ -152,4 +139,6 @@ LxmlLinkExtractor
from elements or attributes which allow leading/trailing whitespaces).
:type strip: boolean
.. automethod:: extract_links
.. _scrapy.linkextractors: https://github.com/scrapy/scrapy/blob/master/scrapy/linkextractors/__init__.py

168
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@ -26,7 +26,7 @@ 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 constructor
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.
@ -35,6 +35,12 @@ Then, you start collecting values into the Item Loader, typically using
the same item field; the Item Loader will know how to "join" those values later
using a proper processing function.
.. note:: Collected data is internally stored as lists,
allowing to add several values to the same field.
If an ``item`` argument is passed when creating a loader,
each of the item's values will be stored as-is if it's already
an iterable, or wrapped with a list if it's a single value.
Here is a typical Item Loader usage in a :ref:`Spider <topics-spiders>`, using
the :ref:`Product item <topics-items-declaring>` declared in the :ref:`Items
chapter <topics-items>`::
@ -128,28 +134,14 @@ So what happens is:
It's worth noticing that processors are just callable objects, which are called
with the data to be parsed, and return a parsed value. So you can use any
function as input or output processor. The only requirement is that they must
accept one (and only one) positional argument, which will be an iterator.
accept one (and only one) positional argument, which will be an iterable.
.. note:: Both input and output processors must receive an iterator as their
.. note:: Both input and output processors must receive an iterable as their
first argument. The output of those functions can be anything. The result of
input processors will be appended to an internal list (in the Loader)
containing the collected values (for that field). The result of the output
processors is the value that will be finally assigned to the item.
If you want to use a plain function as a processor, make sure it receives
``self`` as the first argument::
def lowercase_processor(self, values):
for v in values:
yield v.lower()
class MyItemLoader(ItemLoader):
name_in = lowercase_processor
This is because whenever a function is assigned as a class variable, it becomes
a method and would be passed the instance as the the first argument when being
called. See `this answer on stackoverflow`_ for more details.
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.
@ -157,7 +149,7 @@ 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.
.. _this answer on stackoverflow: https://stackoverflow.com/a/35322635
Declaring Item Loaders
======================
@ -214,14 +206,12 @@ metadata. Here is an example::
output_processor=TakeFirst(),
)
::
>>> 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.load_item()
{'name': u'Welcome to my website', 'price': u'1000'}
>>> 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.load_item()
{'name': u'Welcome to my website', 'price': u'1000'}
The precedence order, for both input and output processors, is as follows:
@ -265,7 +255,7 @@ There are several ways to modify Item Loader context values:
loader.context['unit'] = 'cm'
2. On Item Loader instantiation (the keyword arguments of Item Loader
constructor are stored in the Item Loader context)::
``__init__`` method are stored in the Item Loader context)::
loader = ItemLoader(product, unit='cm')
@ -322,11 +312,11 @@ ItemLoader objects
applied before processors
:type re: str or compiled regex
Examples::
Examples:
>>> from scrapy.loader.processors import TakeFirst
>>> loader.get_value(u'name: foo', TakeFirst(), unicode.upper, re='name: (.+)')
'FOO`
>>> 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)
@ -485,6 +475,8 @@ ItemLoader objects
.. 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
@ -494,7 +486,7 @@ ItemLoader objects
.. attribute:: default_item_class
An Item class (or factory), used to instantiate items when not given in
the constructor.
the ``__init__`` method.
.. attribute:: default_input_processor
@ -509,15 +501,15 @@ ItemLoader objects
.. attribute:: default_selector_class
The class used to construct the :attr:`selector` of this
:class:`ItemLoader`, if only a response is given in the constructor.
If a selector is given in the constructor this attribute is ignored.
: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 constructor or one created from
the response given in the constructor using the
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.
@ -642,46 +634,46 @@ 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 constructor arguments, nor does it
values unchanged. It doesn't receive any ``__init__`` method arguments, nor does it
accept Loader contexts.
Example::
Example:
>>> from scrapy.loader.processors import Identity
>>> proc = Identity()
>>> proc(['one', 'two', 'three'])
['one', 'two', 'three']
>>> 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 constructor arguments, nor does it accept Loader contexts.
It doesn't receive any ``__init__`` method arguments, nor does it accept Loader contexts.
Example::
Example:
>>> from scrapy.loader.processors import TakeFirst
>>> proc = TakeFirst()
>>> proc(['', 'one', 'two', 'three'])
'one'
>>> 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 constructor, which
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::
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'
>>> 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)
@ -694,18 +686,18 @@ Here is a list of all built-in processors:
By default, stop process on ``None`` value. This behaviour can be changed by
passing keyword argument ``stop_on_none=False``.
Example::
Example:
>>> from scrapy.loader.processors import Compose
>>> proc = Compose(lambda v: v[0], str.upper)
>>> proc(['hello', 'world'])
'HELLO'
>>> 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 constructor are used as the default
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`
@ -738,41 +730,41 @@ Here is a list of all built-in processors:
: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::
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']
>>> 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
constructor keyword arguments are used as default context values. See
``__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 constructor and returns the output.
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::
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'}
>>> 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::
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']
>>> 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']

37
docs/topics/logging.rst
View File

@ -171,9 +171,9 @@ listed in `logging's logrecord attributes docs
<https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior>`_
respectively.
If :setting:`LOG_SHORT_NAMES` is set, then the logs will not display the scrapy
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
scrapy component responsible for that log output.
Scrapy component responsible for that log output.
Command-line options
--------------------
@ -193,6 +193,18 @@ to override some of the Scrapy settings regarding logging.
Module `logging.handlers <https://docs.python.org/2/library/logging.handlers.html>`_
Further documentation on available handlers
.. _custom-log-formats:
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:
Advanced customization
----------------------
@ -238,22 +250,23 @@ scrapy.utils.log module
.. autofunction:: configure_logging
``configure_logging`` is automatically called when using Scrapy commands,
but needs to be called explicitly when running custom scripts. In that
case, its usage is not required but it's recommended.
``configure_logging`` is automatically called when using Scrapy commands
or :class:`~scrapy.crawler.CrawlerProcess`, but needs to be called explicitly
when running custom scripts using :class:`~scrapy.crawler.CrawlerRunner`.
In that case, its usage is not required but it's recommended.
If you plan on configuring the handlers yourself is still recommended you
call this function, passing ``install_root_handler=False``. Bear in mind
there won't be any log output set by default in that case.
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 get you started on manually configuring logging's output, you can use
`logging.basicConfig()`_ to set a basic root handler. This is an example
on how to redirect ``INFO`` or higher messages to a file::
Note that :class:`~scrapy.crawler.CrawlerProcess` automatically calls ``configure_logging``,
so it is recommended to only use `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
configure_logging(install_root_handler=False)
logging.basicConfig(
filename='log.txt',
format='%(levelname)s: %(message)s',

98
docs/topics/media-pipeline.rst
View File

@ -97,7 +97,6 @@ For Files Pipeline, use::
ITEM_PIPELINES = {'scrapy.pipelines.files.FilesPipeline': 1}
.. note::
You can also use both the Files and Images Pipeline at the same time.
@ -148,6 +147,25 @@ Where:
* ``full`` is a sub-directory to separate full images from thumbnails (if
used). For more info see :ref:`topics-images-thumbnails`.
FTP server storage
------------------
:setting:`FILES_STORE` and :setting:`IMAGES_STORE` can point to an FTP server.
Scrapy will automatically upload the files to the server.
:setting:`FILES_STORE` and :setting:`IMAGES_STORE` should be written in one of the
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.
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``.
Amazon S3 storage
-----------------
@ -171,7 +189,7 @@ policy::
For more information, see `canned ACLs`_ in the Amazon S3 Developer Guide.
Because Scrapy uses ``boto`` / ``botocore`` internally you can also use other S3-like storages. Storages like
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::
AWS_ENDPOINT_URL = 'http://minio.example.com:9000'
@ -392,6 +410,36 @@ See here the methods that you can override in your custom Files Pipeline:
.. class:: FilesPipeline
.. method:: file_path(self, request, response=None, info=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>`.
You can override this method to customize the download path of each file.
For example, if file URLs end like regular paths (e.g.
``https://example.com/a/b/c/foo.png``), you can use the following
approach to download all files into the ``files`` folder with their
original filenames (e.g. ``files/foo.png``)::
import os
from urllib.parse import urlparse
from scrapy.pipelines.files import FilesPipeline
class MyFilesPipeline(FilesPipeline):
def file_path(self, request, response=None, info=None):
return 'files/' + os.path.basename(urlparse(request.url).path)
By default the :meth:`file_path` method returns
``full/<request URL hash>.<extension>``.
.. method:: FilesPipeline.get_media_requests(item, info)
As seen on the workflow, the pipeline will get the URLs of the images to
@ -411,8 +459,9 @@ See here the methods that you can override in your custom Files Pipeline:
* ``success`` is a boolean which is ``True`` if the image was downloaded
successfully or ``False`` if it failed for some reason
* ``file_info_or_error`` is a dict containing the following keys (if success
is ``True``) or a `Twisted Failure`_ if there was a problem.
* ``file_info_or_error`` is a dict containing the following keys (if
success is ``True``) or a :exc:`~twisted.python.failure.Failure` if
there was a problem.
* ``url`` - the url where the file was downloaded from. This is the url of
the request returned from the :meth:`~get_media_requests`
@ -475,6 +524,36 @@ 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)
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>`.
You can override this method to customize the download path of each file.
For example, if file URLs end like regular paths (e.g.
``https://example.com/a/b/c/foo.png``), you can use the following
approach to download all files into the ``files`` folder with their
original filenames (e.g. ``files/foo.png``)::
import os
from urllib.parse import urlparse
from scrapy.pipelines.images import ImagesPipeline
class MyImagesPipeline(ImagesPipeline):
def file_path(self, request, response=None, info=None):
return 'files/' + os.path.basename(urlparse(request.url).path)
By default the :meth:`file_path` method returns
``full/<request URL hash>.<extension>``.
.. method:: ImagesPipeline.get_media_requests(item, info)
Works the same way as :meth:`FilesPipeline.get_media_requests` method,
@ -497,7 +576,7 @@ See here the methods that you can override in your custom Images Pipeline:
Custom Images pipeline example
==============================
Here is a full example of the Images Pipeline whose methods are examplified
Here is a full example of the Images Pipeline whose methods are exemplified
above::
import scrapy
@ -517,5 +596,12 @@ above::
item['image_paths'] = image_paths
return item
.. _Twisted Failure: https://twistedmatrix.com/documents/current/api/twisted.python.failure.Failure.html
To enable your custom media pipeline component you must add its class import path to the
:setting:`ITEM_PIPELINES` setting, like in the following example::
ITEM_PIPELINES = {
'myproject.pipelines.MyImagesPipeline': 300
}
.. _MD5 hash: https://en.wikipedia.org/wiki/MD5

12
docs/topics/practices.rst
View File

@ -34,15 +34,16 @@ Here's an example showing how to run a single spider with it.
# Your spider definition
...
process = CrawlerProcess({
'USER_AGENT': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)'
process = CrawlerProcess(settings={
'FEED_FORMAT': 'json',
'FEED_URI': 'items.json'
})
process.crawl(MySpider)
process.start() # the script will block here until the crawling is finished
Make sure to check :class:`~scrapy.crawler.CrawlerProcess` documentation to get
acquainted with its usage details.
Define settings within dictionary in CrawlerProcess. Make sure to check :class:`~scrapy.crawler.CrawlerProcess`
documentation to get acquainted with its usage details.
If you are inside a Scrapy project there are some additional helpers you can
use to import those components within the project. You can automatically import
@ -100,7 +101,7 @@ reactor after ``MySpider`` has finished running.
d.addBoth(lambda _: reactor.stop())
reactor.run() # the script will block here until the crawling is finished
.. seealso:: `Twisted Reactor Overview`_.
.. seealso:: :doc:`twisted:core/howto/reactor-basics`
.. _run-multiple-spiders:
@ -252,6 +253,5 @@ 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
.. _Twisted Reactor Overview: https://twistedmatrix.com/documents/current/core/howto/reactor-basics.html
.. _Crawlera: https://scrapinghub.com/crawlera
.. _scrapoxy: https://scrapoxy.io/

126
docs/topics/request-response.rst
View File

@ -24,7 +24,7 @@ below in :ref:`topics-request-response-ref-request-subclasses` and
Request objects
===============
.. class:: Request(url[, callback, method='GET', headers, body, cookies, meta, encoding='utf-8', priority=0, dont_filter=False, errback, flags])
.. 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
@ -83,17 +83,21 @@ Request objects
.. reqmeta:: dont_merge_cookies
When some site returns cookies (in a response) those are stored in the
cookies for that domain and will be sent again in future requests. That's
the typical behaviour of any regular web browser. However, if, for some
reason, you want to avoid merging with existing cookies you can instruct
Scrapy to do so by setting the ``dont_merge_cookies`` key to True in the
:attr:`Request.meta`.
cookies for that domain and will be sent again in future requests.
That's the typical behaviour of any regular web browser.
Example of request without merging cookies::
To create a request that does not send stored cookies and does not
store received cookies, set the ``dont_merge_cookies`` key to ``True``
in :attr:`request.meta <scrapy.http.Request.meta>`.
request_with_cookies = Request(url="http://www.example.com",
cookies={'currency': 'USD', 'country': 'UY'},
meta={'dont_merge_cookies': True})
Example of a request that sends manually-defined cookies and ignores
cookie storage::
Request(
url="http://www.example.com",
cookies={'currency': 'USD', 'country': 'UY'},
meta={'dont_merge_cookies': True},
)
For more info see :ref:`cookies-mw`.
:type cookies: dict or list
@ -117,8 +121,8 @@ Request objects
:param errback: a function that will be called if any exception was
raised while processing the request. This includes pages that failed
with 404 HTTP errors and such. It receives a `Twisted Failure`_ instance
as first parameter.
with 404 HTTP errors and such. It receives a
:exc:`~twisted.python.failure.Failure` as first parameter.
For more information,
see :ref:`topics-request-response-ref-errbacks` below.
:type errback: callable
@ -126,11 +130,14 @@ Request objects
:param flags: Flags sent to the request, can be used for logging or similar purposes.
:type flags: list
:param cb_kwargs: A dict with arbitrary data that will be passed as keyword arguments to the Request's callback.
:type cb_kwargs: dict
.. attribute:: Request.url
A string containing the URL of this request. Keep in mind that this
attribute contains the escaped URL, so it can differ from the URL passed in
the constructor.
the ``__init__`` method.
This attribute is read-only. To change the URL of a Request use
:meth:`replace`.
@ -165,6 +172,17 @@ Request objects
``copy()`` or ``replace()`` methods, and can also be accessed, in your
spider, from the ``response.meta`` attribute.
.. attribute:: Request.cb_kwargs
A dictionary that contains arbitrary metadata for this request. Its contents
will be passed to the Request's callback as keyword arguments. It is empty
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.
.. _shallow copied: https://docs.python.org/2/library/copy.html
.. method:: Request.copy()
@ -172,14 +190,16 @@ Request objects
Return a new Request which is a copy of this Request. See also:
:ref:`topics-request-response-ref-request-callback-arguments`.
.. method:: Request.replace([url, method, headers, body, cookies, meta, encoding, dont_filter, callback, errback])
.. method:: Request.replace([url, method, headers, body, cookies, meta, flags, encoding, priority, dont_filter, callback, errback, cb_kwargs])
Return a Request object with the same members, except for those members
given new values by whichever keyword arguments are specified. The
attribute :attr:`Request.meta` is copied by default (unless a new value
is given in the ``meta`` argument). See also
:attr:`Request.cb_kwargs` and :attr:`Request.meta` attributes are shallow
copied by default (unless new values are given as arguments). See also
:ref:`topics-request-response-ref-request-callback-arguments`.
.. automethod:: from_curl
.. _topics-request-response-ref-request-callback-arguments:
Passing additional data to callback functions
@ -200,25 +220,31 @@ Example::
self.logger.info("Visited %s", response.url)
In some cases you may be interested in passing arguments to those callback
functions so you can receive the arguments later, in the second callback. You
can use the :attr:`Request.meta` attribute for that.
functions so you can receive the arguments later, in the second callback.
The following example shows how to achieve this by using the
:attr:`Request.cb_kwargs` attribute:
Here's an example of how to pass an item using this mechanism, to populate
different fields from different pages::
::
def parse_page1(self, response):
item = MyItem()
item['main_url'] = response.url
request = scrapy.Request("http://www.example.com/some_page.html",
callback=self.parse_page2)
request.meta['item'] = item
def parse(self, response):
request = scrapy.Request('http://www.example.com/index.html',
callback=self.parse_page2,
cb_kwargs=dict(main_url=response.url))
request.cb_kwargs['foo'] = 'bar' # add more arguments for the callback
yield request
def parse_page2(self, response):
item = response.meta['item']
item['other_url'] = response.url
yield item
def parse_page2(self, response, main_url, foo):
yield dict(
main_url=main_url,
other_url=response.url,
foo=foo,
)
.. caution:: :attr:`Request.cb_kwargs` was introduced in version ``1.7``.
Prior to that, using :attr:`Request.meta` was recommended for passing
information around callbacks. After ``1.7``, :attr:`Request.cb_kwargs`
became the preferred way for handling user information, leaving :attr:`Request.meta`
for communication with components like middlewares and extensions.
.. _topics-request-response-ref-errbacks:
@ -228,8 +254,8 @@ Using errbacks to catch exceptions in request processing
The errback of a request is a function that will be called when an exception
is raise while processing it.
It receives a `Twisted Failure`_ instance as first parameter and can be
used to track connection establishment timeouts, DNS errors etc.
It receives a :exc:`~twisted.python.failure.Failure` as first parameter and can
be used to track connection establishment timeouts, DNS errors etc.
Here's an example spider logging all errors and catching some specific
errors if needed::
@ -299,6 +325,7 @@ Those are:
* :reqmeta:`dont_merge_cookies`
* :reqmeta:`cookiejar`
* :reqmeta:`dont_cache`
* :reqmeta:`redirect_reasons`
* :reqmeta:`redirect_urls`
* :reqmeta:`bindaddress`
* :reqmeta:`dont_obey_robotstxt`
@ -373,7 +400,7 @@ fields with form data from :class:`Response` objects.
.. class:: FormRequest(url, [formdata, ...])
The :class:`FormRequest` class adds a new argument to the constructor. The
The :class:`FormRequest` class adds a new keyword parameter to the ``__init__`` method. The
remaining arguments are the same as for the :class:`Request` class and are
not documented here.
@ -446,7 +473,7 @@ fields with form data from :class:`Response` objects.
:type dont_click: boolean
The other parameters of this class method are passed directly to the
:class:`FormRequest` constructor.
:class:`FormRequest` ``__init__`` method.
.. versionadded:: 0.10.3
The ``formname`` parameter.
@ -512,24 +539,24 @@ method for this job. Here's an example spider which uses it::
# continue scraping with authenticated session...
JSONRequest
JsonRequest
-----------
The JSONRequest class extends the base :class:`Request` class with functionality for
The JsonRequest class extends the base :class:`Request` class with functionality for
dealing with JSON requests.
.. class:: JSONRequest(url, [... data, dumps_kwargs])
.. class:: JsonRequest(url, [... data, dumps_kwargs])
The :class:`JSONRequest` class adds two new argument to the constructor. The
The :class:`JsonRequest` class adds two new keyword parameters to the ``__init__`` method. The
remaining arguments are the same as for the :class:`Request` class and are
not documented here.
Using the :class:`JSONRequest` will set the ``Content-Type`` header to ``application/json``
Using the :class:`JsonRequest` will set the ``Content-Type`` header to ``application/json``
and ``Accept`` header to ``application/json, text/javascript, */*; q=0.01``
:param data: is any JSON serializable object that needs to be JSON encoded and assigned to body.
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
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
@ -539,7 +566,7 @@ dealing with JSON requests.
.. _json.dumps: https://docs.python.org/3/library/json.html#json.dumps
JSONRequest usage example
JsonRequest usage example
-------------------------
Sending a JSON POST request with a JSON payload::
@ -548,13 +575,13 @@ Sending a JSON POST request with a JSON payload::
'name1': 'value1',
'name2': 'value2',
}
yield JSONRequest(url='http://www.example.com/post/action', data=data)
yield JsonRequest(url='http://www.example.com/post/action', data=data)
Response objects
================
.. class:: Response(url, [status=200, headers=None, body=b'', flags=None, request=None])
.. autoclass:: Response
A :class:`Response` object represents an HTTP response, which is usually
downloaded (by the Downloader) and fed to the Spiders for processing.
@ -569,8 +596,8 @@ Response objects
(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 (unicode
in Python 2) you can use ``response.text`` from an encoding-aware
:param body: the response body. To access the decoded text as str you can use
``response.text`` from an encoding-aware
:ref:`Response subclass <topics-request-response-ref-response-subclasses>`,
such as :class:`TextResponse`.
:type body: bytes
@ -674,6 +701,8 @@ Response objects
.. automethod:: Response.follow
.. automethod:: Response.follow_all
.. _urlparse.urljoin: https://docs.python.org/2/library/urlparse.html#urlparse.urljoin
@ -694,7 +723,7 @@ TextResponse objects
:class:`Response` class, which is meant to be used only for binary data,
such as images, sounds or any media file.
:class:`TextResponse` objects support a new constructor argument, in
:class:`TextResponse` objects support a new ``__init__`` method argument, in
addition to the base :class:`Response` objects. The remaining functionality
is the same as for the :class:`Response` class and is not documented here.
@ -728,7 +757,7 @@ TextResponse objects
A string with the encoding of this response. The encoding is resolved by
trying the following mechanisms, in order:
1. the encoding passed in the constructor ``encoding`` argument
1. the encoding passed in the ``__init__`` method ``encoding`` argument
2. the encoding declared in the Content-Type HTTP header. If this
encoding is not valid (ie. unknown), it is ignored and the next
@ -763,6 +792,8 @@ TextResponse objects
.. automethod:: TextResponse.follow
.. automethod:: TextResponse.follow_all
.. method:: TextResponse.body_as_unicode()
The same as :attr:`text`, but available as a method. This method is
@ -789,5 +820,4 @@ XmlResponse objects
adds encoding auto-discovering support by looking into the XML declaration
line. See :attr:`TextResponse.encoding`.
.. _Twisted Failure: https://twistedmatrix.com/documents/current/api/twisted.python.failure.Failure.html
.. _bug in lxml: https://bugs.launchpad.net/lxml/+bug/1665241

565
docs/topics/selectors.rst
View File

@ -51,18 +51,18 @@ Constructing selectors
.. highlight:: python
Response objects expose a :class:`~scrapy.selector.Selector` instance
on ``.selector`` attribute::
on ``.selector`` attribute:
>>> response.selector.xpath('//span/text()').get()
'good'
>>> response.selector.xpath('//span/text()').get()
'good'
Querying responses using XPath and CSS is so common that responses include two
more shortcuts: ``response.xpath()`` and ``response.css()``::
more shortcuts: ``response.xpath()`` and ``response.css()``:
>>> response.xpath('//span/text()').get()
'good'
>>> response.css('span::text').get()
'good'
>>> response.xpath('//span/text()').get()
'good'
>>> response.css('span::text').get()
'good'
Scrapy selectors are instances of :class:`~scrapy.selector.Selector` class
constructed by passing either :class:`~scrapy.http.TextResponse` object or
@ -74,21 +74,21 @@ shortcuts. By using ``response.selector`` or one of these shortcuts
you can also ensure the response body is parsed only once.
But if required, it is possible to use ``Selector`` directly.
Constructing from text::
Constructing from text:
>>> from scrapy.selector import Selector
>>> body = '<html><body><span>good</span></body></html>'
>>> Selector(text=body).xpath('//span/text()').get()
'good'
>>> from scrapy.selector import Selector
>>> body = '<html><body><span>good</span></body></html>'
>>> Selector(text=body).xpath('//span/text()').get()
'good'
Constructing from response - :class:`~scrapy.http.HtmlResponse` is one of
:class:`~scrapy.http.TextResponse` subclasses::
:class:`~scrapy.http.TextResponse` subclasses:
>>> from scrapy.selector import Selector
>>> from scrapy.http import HtmlResponse
>>> response = HtmlResponse(url='http://example.com', body=body)
>>> Selector(response=response).xpath('//span/text()').get()
'good'
>>> from scrapy.selector import Selector
>>> from scrapy.http import HtmlResponse
>>> response = HtmlResponse(url='http://example.com', body=body)
>>> Selector(response=response).xpath('//span/text()').get()
'good'
``Selector`` automatically chooses the best parsing rules
(XML vs HTML) based on input type.
@ -123,118 +123,118 @@ Since we're dealing with HTML, the selector will automatically use an HTML parse
.. highlight:: python
So, by looking at the :ref:`HTML code <topics-selectors-htmlcode>` of that
page, let's construct an XPath for selecting the text inside the title tag::
page, let's construct an XPath for selecting the text inside the title tag:
>>> response.xpath('//title/text()')
[<Selector xpath='//title/text()' data='Example website'>]
>>> response.xpath('//title/text()')
[<Selector xpath='//title/text()' data='Example website'>]
To actually extract the textual data, you must call the selector ``.get()``
or ``.getall()`` methods, as follows::
or ``.getall()`` methods, as follows:
>>> response.xpath('//title/text()').getall()
['Example website']
>>> response.xpath('//title/text()').get()
'Example website'
>>> response.xpath('//title/text()').getall()
['Example website']
>>> response.xpath('//title/text()').get()
'Example website'
``.get()`` always returns a single result; if there are several matches,
content of a first match is returned; if there are no matches, None
is returned. ``.getall()`` returns a list with all results.
Notice that CSS selectors can select text or attribute nodes using CSS3
pseudo-elements::
pseudo-elements:
>>> response.css('title::text').get()
'Example website'
>>> response.css('title::text').get()
'Example website'
As you can see, ``.xpath()`` and ``.css()`` methods return a
:class:`~scrapy.selector.SelectorList` instance, which is a list of new
selectors. This API can be used for quickly selecting nested data::
selectors. This API can be used for quickly selecting nested data:
>>> response.css('img').xpath('@src').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
>>> response.css('img').xpath('@src').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
If you want to extract only the first matched element, you can call the
selector ``.get()`` (or its alias ``.extract_first()`` commonly used in
previous Scrapy versions)::
previous Scrapy versions):
>>> response.xpath('//div[@id="images"]/a/text()').get()
'Name: My image 1 '
>>> response.xpath('//div[@id="images"]/a/text()').get()
'Name: My image 1 '
It returns ``None`` if no element was found::
It returns ``None`` if no element was found:
>>> response.xpath('//div[@id="not-exists"]/text()').get() is None
True
>>> response.xpath('//div[@id="not-exists"]/text()').get() is None
True
A default return value can be provided as an argument, to be used instead
of ``None``:
>>> response.xpath('//div[@id="not-exists"]/text()').get(default='not-found')
'not-found'
>>> response.xpath('//div[@id="not-exists"]/text()').get(default='not-found')
'not-found'
Instead of using e.g. ``'@src'`` XPath it is possible to query for attributes
using ``.attrib`` property of a :class:`~scrapy.selector.Selector`::
using ``.attrib`` property of a :class:`~scrapy.selector.Selector`:
>>> [img.attrib['src'] for img in response.css('img')]
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
>>> [img.attrib['src'] for img in response.css('img')]
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
As a shortcut, ``.attrib`` is also available on SelectorList directly;
it returns attributes for the first matching element::
it returns attributes for the first matching element:
>>> response.css('img').attrib['src']
'image1_thumb.jpg'
>>> response.css('img').attrib['src']
'image1_thumb.jpg'
This is most useful when only a single result is expected, e.g. when selecting
by id, or selecting unique elements on a web page::
by id, or selecting unique elements on a web page:
>>> response.css('base').attrib['href']
'http://example.com/'
>>> response.css('base').attrib['href']
'http://example.com/'
Now we're going to get the base URL and some image links::
Now we're going to get the base URL and some image links:
>>> response.xpath('//base/@href').get()
'http://example.com/'
>>> response.xpath('//base/@href').get()
'http://example.com/'
>>> response.css('base::attr(href)').get()
'http://example.com/'
>>> response.css('base::attr(href)').get()
'http://example.com/'
>>> response.css('base').attrib['href']
'http://example.com/'
>>> response.css('base').attrib['href']
'http://example.com/'
>>> response.xpath('//a[contains(@href, "image")]/@href').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
>>> response.xpath('//a[contains(@href, "image")]/@href').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
>>> response.css('a[href*=image]::attr(href)').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
>>> response.css('a[href*=image]::attr(href)').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
>>> response.xpath('//a[contains(@href, "image")]/img/@src').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
>>> response.xpath('//a[contains(@href, "image")]/img/@src').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
>>> response.css('a[href*=image] img::attr(src)').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
>>> response.css('a[href*=image] img::attr(src)').getall()
['image1_thumb.jpg',
'image2_thumb.jpg',
'image3_thumb.jpg',
'image4_thumb.jpg',
'image5_thumb.jpg']
.. _topics-selectors-css-extensions:
@ -259,47 +259,47 @@ that Scrapy (parsel) implements a couple of **non-standard pseudo-elements**:
Examples:
* ``title::text`` selects children text nodes of a descendant ``<title>`` element::
* ``title::text`` selects children text nodes of a descendant ``<title>`` element:
>>> response.css('title::text').get()
'Example website'
>>> response.css('title::text').get()
'Example website'
* ``*::text`` selects all descendant text nodes of the current selector context::
* ``*::text`` selects all descendant text nodes of the current selector context:
>>> response.css('#images *::text').getall()
['\n ',
'Name: My image 1 ',
'\n ',
'Name: My image 2 ',
'\n ',
'Name: My image 3 ',
'\n ',
'Name: My image 4 ',
'\n ',
'Name: My image 5 ',
'\n ']
>>> response.css('#images *::text').getall()
['\n ',
'Name: My image 1 ',
'\n ',
'Name: My image 2 ',
'\n ',
'Name: My image 3 ',
'\n ',
'Name: My image 4 ',
'\n ',
'Name: My image 5 ',
'\n ']
* ``foo::text`` returns no results if ``foo`` element exists, but contains
no text (i.e. text is empty)::
no text (i.e. text is empty):
>>> response.css('img::text').getall()
[]
>>> response.css('img::text').getall()
[]
This means ``.css('foo::text').get()`` could return None even if an element
exists. Use ``default=''`` if you always want a string::
exists. Use ``default=''`` if you always want a string:
>>> response.css('img::text').get()
>>> response.css('img::text').get(default='')
''
>>> response.css('img::text').get()
>>> response.css('img::text').get(default='')
''
* ``a::attr(href)`` selects the *href* attribute value of descendant links::
* ``a::attr(href)`` selects the *href* attribute value of descendant links:
>>> response.css('a::attr(href)').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
>>> response.css('a::attr(href)').getall()
['image1.html',
'image2.html',
'image3.html',
'image4.html',
'image5.html']
.. note::
See also: :ref:`selecting-attributes`.
@ -318,25 +318,24 @@ Nesting selectors
The selection methods (``.xpath()`` or ``.css()``) return a list of selectors
of the same type, so you can call the selection methods for those selectors
too. Here's an example::
too. Here's an example:
>>> links = response.xpath('//a[contains(@href, "image")]')
>>> links.getall()
['<a href="image1.html">Name: My image 1 <br><img src="image1_thumb.jpg"></a>',
'<a href="image2.html">Name: My image 2 <br><img src="image2_thumb.jpg"></a>',
'<a href="image3.html">Name: My image 3 <br><img src="image3_thumb.jpg"></a>',
'<a href="image4.html">Name: My image 4 <br><img src="image4_thumb.jpg"></a>',
'<a href="image5.html">Name: My image 5 <br><img src="image5_thumb.jpg"></a>']
>>> links = response.xpath('//a[contains(@href, "image")]')
>>> links.getall()
['<a href="image1.html">Name: My image 1 <br><img src="image1_thumb.jpg"></a>',
'<a href="image2.html">Name: My image 2 <br><img src="image2_thumb.jpg"></a>',
'<a href="image3.html">Name: My image 3 <br><img src="image3_thumb.jpg"></a>',
'<a href="image4.html">Name: My image 4 <br><img src="image4_thumb.jpg"></a>',
'<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)
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'
Link number 3 points to url 'image4.html' and image 'image4_thumb.jpg'
Link number 4 points to url 'image5.html' and image 'image5_thumb.jpg'
>>> 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)
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'
Link number 3 points to url 'image4.html' and image 'image4_thumb.jpg'
Link number 4 points to url 'image5.html' and image 'image5_thumb.jpg'
.. _selecting-attributes:
@ -344,42 +343,42 @@ Selecting element attributes
----------------------------
There are several ways to get a value of an attribute. First, one can use
XPath syntax::
XPath syntax:
>>> response.xpath("//a/@href").getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> response.xpath("//a/@href").getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
XPath syntax has a few advantages: it is a standard XPath feature, and
``@attributes`` can be used in other parts of an XPath expression - e.g.
it is possible to filter by attribute value.
Scrapy also provides an extension to CSS selectors (``::attr(...)``)
which allows to get attribute values::
which allows to get attribute values:
>>> response.css('a::attr(href)').getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> response.css('a::attr(href)').getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
In addition to that, there is a ``.attrib`` property of Selector.
You can use it if you prefer to lookup attributes in Python
code, without using XPaths or CSS extensions::
code, without using XPaths or CSS extensions:
>>> [a.attrib['href'] for a in response.css('a')]
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> [a.attrib['href'] for a in response.css('a')]
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
This property is also available on SelectorList; it returns a dictionary
with attributes of a first matching element. It is convenient to use when
a selector is expected to give a single result (e.g. when selecting by element
ID, or when selecting an unique element on a page)::
ID, or when selecting an unique element on a page):
>>> response.css('base').attrib
{'href': 'http://example.com/'}
>>> response.css('base').attrib['href']
'http://example.com/'
>>> response.css('base').attrib
{'href': 'http://example.com/'}
>>> response.css('base').attrib['href']
'http://example.com/'
``.attrib`` property of an empty SelectorList is empty::
``.attrib`` property of an empty SelectorList is empty:
>>> response.css('foo').attrib
{}
>>> response.css('foo').attrib
{}
Using selectors with regular expressions
----------------------------------------
@ -390,21 +389,21 @@ data using regular expressions. However, unlike using ``.xpath()`` or
can't construct nested ``.re()`` calls.
Here's an example used to extract image names from the :ref:`HTML code
<topics-selectors-htmlcode>` above::
<topics-selectors-htmlcode>` above:
>>> response.xpath('//a[contains(@href, "image")]/text()').re(r'Name:\s*(.*)')
['My image 1',
'My image 2',
'My image 3',
'My image 4',
'My image 5']
>>> response.xpath('//a[contains(@href, "image")]/text()').re(r'Name:\s*(.*)')
['My image 1',
'My image 2',
'My image 3',
'My image 4',
'My image 5']
There's an additional helper reciprocating ``.get()`` (and its
alias ``.extract_first()``) for ``.re()``, named ``.re_first()``.
Use it to extract just the first matching string::
Use it to extract just the first matching string:
>>> response.xpath('//a[contains(@href, "image")]/text()').re_first(r'Name:\s*(.*)')
'My image 1'
>>> response.xpath('//a[contains(@href, "image")]/text()').re_first(r'Name:\s*(.*)')
'My image 1'
.. _old-extraction-api:
@ -422,28 +421,28 @@ and readable code.
The following examples show how these methods map to each other.
1. ``SelectorList.get()`` is the same as ``SelectorList.extract_first()``::
1. ``SelectorList.get()`` is the same as ``SelectorList.extract_first()``:
>>> response.css('a::attr(href)').get()
'image1.html'
>>> response.css('a::attr(href)').extract_first()
'image1.html'
>>> response.css('a::attr(href)').get()
'image1.html'
>>> response.css('a::attr(href)').extract_first()
'image1.html'
2. ``SelectorList.getall()`` is the same as ``SelectorList.extract()``::
2. ``SelectorList.getall()`` is the same as ``SelectorList.extract()``:
>>> response.css('a::attr(href)').getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> response.css('a::attr(href)').extract()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> response.css('a::attr(href)').getall()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
>>> response.css('a::attr(href)').extract()
['image1.html', 'image2.html', 'image3.html', 'image4.html', 'image5.html']
3. ``Selector.get()`` is the same as ``Selector.extract()``::
3. ``Selector.get()`` is the same as ``Selector.extract()``:
>>> response.css('a::attr(href)')[0].get()
'image1.html'
>>> response.css('a::attr(href)')[0].extract()
'image1.html'
>>> response.css('a::attr(href)')[0].get()
'image1.html'
>>> response.css('a::attr(href)')[0].extract()
'image1.html'
4. For consistency, there is also ``Selector.getall()``, which returns a list::
4. For consistency, there is also ``Selector.getall()``, which returns a list:
>>> response.css('a::attr(href)')[0].getall()
['image1.html']
@ -481,26 +480,26 @@ with ``/``, that XPath will be absolute to the document and not relative to the
``Selector`` you're calling it from.
For example, suppose you want to extract all ``<p>`` elements inside ``<div>``
elements. First, you would get all ``<div>`` elements::
elements. First, you would get all ``<div>`` elements:
>>> divs = response.xpath('//div')
>>> divs = response.xpath('//div')
At first, you may be tempted to use the following approach, which is wrong, as
it actually extracts all ``<p>`` elements from the document, not only those
inside ``<div>`` elements::
inside ``<div>`` elements:
>>> for p in divs.xpath('//p'): # this is wrong - gets all <p> from the whole document
... print(p.get())
>>> for p in divs.xpath('//p'): # this is wrong - gets all <p> from the whole document
... print(p.get())
This is the proper way to do it (note the dot prefixing the ``.//p`` XPath)::
This is the proper way to do it (note the dot prefixing the ``.//p`` XPath):
>>> for p in divs.xpath('.//p'): # extracts all <p> inside
... print(p.get())
>>> for p in divs.xpath('.//p'): # extracts all <p> inside
... print(p.get())
Another common case would be to extract all direct ``<p>`` children::
Another common case would be to extract all direct ``<p>`` children:
>>> for p in divs.xpath('p'):
... print(p.get())
>>> for p in divs.xpath('p'):
... print(p.get())
For more details about relative XPaths see the `Location Paths`_ section in the
XPath specification.
@ -521,12 +520,12 @@ for that you may end up with more elements that you want, if they have a differe
class name that shares the string ``someclass``.
As it turns out, Scrapy selectors allow you to chain selectors, so most of the time
you can just select by class using CSS and then switch to XPath when needed::
you can just select by class using CSS and then switch to XPath when needed:
>>> from scrapy import Selector
>>> sel = Selector(text='<div class="hero shout"><time datetime="2014-07-23 19:00">Special date</time></div>')
>>> sel.css('.shout').xpath('./time/@datetime').getall()
['2014-07-23 19:00']
>>> from scrapy import Selector
>>> sel = Selector(text='<div class="hero shout"><time datetime="2014-07-23 19:00">Special date</time></div>')
>>> sel.css('.shout').xpath('./time/@datetime').getall()
['2014-07-23 19:00']
This is cleaner than using the verbose XPath trick shown above. Just remember
to use the ``.`` in the XPath expressions that will follow.
@ -538,41 +537,41 @@ Beware of the difference between //node[1] and (//node)[1]
``(//node)[1]`` selects all the nodes in the document, and then gets only the first of them.
Example::
Example:
>>> from scrapy import Selector
>>> sel = Selector(text="""
....: <ul class="list">
....: <li>1</li>
....: <li>2</li>
....: <li>3</li>
....: </ul>
....: <ul class="list">
....: <li>4</li>
....: <li>5</li>
....: <li>6</li>
....: </ul>""")
>>> xp = lambda x: sel.xpath(x).getall()
>>> from scrapy import Selector
>>> sel = Selector(text="""
....: <ul class="list">
....: <li>1</li>
....: <li>2</li>
....: <li>3</li>
....: </ul>
....: <ul class="list">
....: <li>4</li>
....: <li>5</li>
....: <li>6</li>
....: </ul>""")
>>> xp = lambda x: sel.xpath(x).getall()
This gets all first ``<li>`` elements under whatever it is its parent::
This gets all first ``<li>`` elements under whatever it is its parent:
>>> xp("//li[1]")
['<li>1</li>', '<li>4</li>']
>>> xp("//li[1]")
['<li>1</li>', '<li>4</li>']
And this gets the first ``<li>`` element in the whole document::
And this gets the first ``<li>`` element in the whole document:
>>> xp("(//li)[1]")
['<li>1</li>']
>>> xp("(//li)[1]")
['<li>1</li>']
This gets all first ``<li>`` elements under an ``<ul>`` parent::
This gets all first ``<li>`` elements under an ``<ul>`` parent:
>>> xp("//ul/li[1]")
['<li>1</li>', '<li>4</li>']
>>> xp("//ul/li[1]")
['<li>1</li>', '<li>4</li>']
And this gets the first ``<li>`` element under an ``<ul>`` parent in the whole document::
And this gets the first ``<li>`` element under an ``<ul>`` parent in the whole document:
>>> xp("(//ul/li)[1]")
['<li>1</li>']
>>> xp("(//ul/li)[1]")
['<li>1</li>']
Using text nodes in a condition
-------------------------------
@ -584,34 +583,34 @@ This is because the expression ``.//text()`` yields a collection of text element
And when a node-set is converted to a string, which happens when it is passed as argument to
a string function like ``contains()`` or ``starts-with()``, it results in the text for the first element only.
Example::
Example:
>>> from scrapy import Selector
>>> sel = Selector(text='<a href="#">Click here to go to the <strong>Next Page</strong></a>')
>>> from scrapy import Selector
>>> sel = Selector(text='<a href="#">Click here to go to the <strong>Next Page</strong></a>')
Converting a *node-set* to string::
Converting a *node-set* to string:
>>> sel.xpath('//a//text()').getall() # take a peek at the node-set
['Click here to go to the ', 'Next Page']
>>> sel.xpath("string(//a[1]//text())").getall() # convert it to string
['Click here to go to the ']
>>> sel.xpath('//a//text()').getall() # take a peek at the node-set
['Click here to go to the ', 'Next Page']
>>> sel.xpath("string(//a[1]//text())").getall() # convert it to string
['Click here to go to the ']
A *node* converted to a string, however, puts together the text of itself plus of all its descendants::
A *node* converted to a string, however, puts together the text of itself plus of all its descendants:
>>> sel.xpath("//a[1]").getall() # select the first node
['<a href="#">Click here to go to the <strong>Next Page</strong></a>']
>>> sel.xpath("string(//a[1])").getall() # convert it to string
['Click here to go to the Next Page']
>>> sel.xpath("//a[1]").getall() # select the first node
['<a href="#">Click here to go to the <strong>Next Page</strong></a>']
>>> sel.xpath("string(//a[1])").getall() # convert it to string
['Click here to go to the Next Page']
So, using the ``.//text()`` node-set won't select anything in this case::
So, using the ``.//text()`` node-set won't select anything in this case:
>>> sel.xpath("//a[contains(.//text(), 'Next Page')]").getall()
[]
>>> sel.xpath("//a[contains(.//text(), 'Next Page')]").getall()
[]
But using the ``.`` to mean the node, works::
But using the ``.`` to mean the node, works:
>>> sel.xpath("//a[contains(., 'Next Page')]").getall()
['<a href="#">Click here to go to the <strong>Next Page</strong></a>']
>>> sel.xpath("//a[contains(., 'Next Page')]").getall()
['<a href="#">Click here to go to the <strong>Next Page</strong></a>']
.. _`XPath string function`: https://www.w3.org/TR/xpath/#section-String-Functions
@ -627,17 +626,17 @@ some arguments in your queries with placeholders like ``?``,
which are then substituted with values passed with the query.
Here's an example to match an element based on its "id" attribute value,
without hard-coding it (that was shown previously)::
without hard-coding it (that was shown previously):
>>> # `$val` used in the expression, a `val` argument needs to be passed
>>> response.xpath('//div[@id=$val]/a/text()', val='images').get()
'Name: My image 1 '
>>> # `$val` used in the expression, a `val` argument needs to be passed
>>> response.xpath('//div[@id=$val]/a/text()', val='images').get()
'Name: My image 1 '
Here's another example, to find the "id" attribute of a ``<div>`` tag containing
five ``<a>`` children (here we pass the value ``5`` as an integer)::
five ``<a>`` children (here we pass the value ``5`` as an integer):
>>> response.xpath('//div[count(a)=$cnt]/@id', cnt=5).get()
'images'
>>> response.xpath('//div[count(a)=$cnt]/@id', cnt=5).get()
'images'
All variable references must have a binding value when calling ``.xpath()``
(otherwise you'll get a ``ValueError: XPath error:`` exception).
@ -687,19 +686,19 @@ You can see several namespace declarations including a default
.. highlight:: python
Once in the shell we can try selecting all ``<link>`` objects and see that it
doesn't work (because the Atom XML namespace is obfuscating those nodes)::
doesn't work (because the Atom XML namespace is obfuscating those nodes):
>>> response.xpath("//link")
[]
>>> response.xpath("//link")
[]
But once we call the :meth:`Selector.remove_namespaces` method, all
nodes can be accessed directly by their names::
nodes can be accessed directly by their names:
>>> response.selector.remove_namespaces()
>>> response.xpath("//link")
[<Selector xpath='//link' data='<link rel="alternate" type="text/html" h'>,
<Selector xpath='//link' data='<link rel="next" type="application/atom+'>,
...
>>> response.selector.remove_namespaces()
>>> response.xpath("//link")
[<Selector xpath='//link' data='<link rel="alternate" type="text/html" h'>,
<Selector xpath='//link' data='<link rel="next" type="application/atom+'>,
...
If you wonder why the namespace removal procedure isn't always called by default
instead of having to call it manually, this is because of two reasons, which, in order
@ -734,26 +733,25 @@ Regular expressions
The ``test()`` function, for example, can prove quite useful when XPath's
``starts-with()`` or ``contains()`` are not sufficient.
Example selecting links in list item with a "class" attribute ending with a digit::
Example selecting links in list item with a "class" attribute ending with a digit:
>>> from scrapy import Selector
>>> doc = u"""
... <div>
... <ul>
... <li class="item-0"><a href="link1.html">first item</a></li>
... <li class="item-1"><a href="link2.html">second item</a></li>
... <li class="item-inactive"><a href="link3.html">third item</a></li>
... <li class="item-1"><a href="link4.html">fourth item</a></li>
... <li class="item-0"><a href="link5.html">fifth item</a></li>
... </ul>
... </div>
... """
>>> sel = Selector(text=doc, type="html")
>>> sel.xpath('//li//@href').getall()
['link1.html', 'link2.html', 'link3.html', 'link4.html', 'link5.html']
>>> sel.xpath('//li[re:test(@class, "item-\d$")]//@href').getall()
['link1.html', 'link2.html', 'link4.html', 'link5.html']
>>>
>>> from scrapy import Selector
>>> doc = u"""
... <div>
... <ul>
... <li class="item-0"><a href="link1.html">first item</a></li>
... <li class="item-1"><a href="link2.html">second item</a></li>
... <li class="item-inactive"><a href="link3.html">third item</a></li>
... <li class="item-1"><a href="link4.html">fourth item</a></li>
... <li class="item-0"><a href="link5.html">fifth item</a></li>
... </ul>
... </div>
... """
>>> sel = Selector(text=doc, type="html")
>>> sel.xpath('//li//@href').getall()
['link1.html', 'link2.html', 'link3.html', 'link4.html', 'link5.html']
>>> sel.xpath('//li[re:test(@class, "item-\d$")]//@href').getall()
['link1.html', 'link2.html', 'link4.html', 'link5.html']
.. warning:: C library ``libxslt`` doesn't natively support EXSLT regular
expressions so `lxml`_'s implementation uses hooks to Python's ``re`` module.
@ -849,7 +847,6 @@ with groups of itemscopes and corresponding itemprops::
current scope: ['http://schema.org/Rating']
properties: ['worstRating', 'ratingValue', 'bestRating']
>>>
Here we first iterate over ``itemscope`` elements, and for each one,
we look for all ``itemprops`` elements and exclude those that are themselves
@ -877,15 +874,15 @@ For the following HTML::
.. highlight:: python
You can use it like this::
You can use it like this:
>>> response.xpath('//p[has-class("foo")]')
[<Selector xpath='//p[has-class("foo")]' data='<p class="foo bar-baz">First</p>'>,
<Selector xpath='//p[has-class("foo")]' data='<p class="foo">Second</p>'>]
>>> response.xpath('//p[has-class("foo", "bar-baz")]')
[<Selector xpath='//p[has-class("foo", "bar-baz")]' data='<p class="foo bar-baz">First</p>'>]
>>> response.xpath('//p[has-class("foo", "bar")]')
[]
>>> response.xpath('//p[has-class("foo")]')
[<Selector xpath='//p[has-class("foo")]' data='<p class="foo bar-baz">First</p>'>,
<Selector xpath='//p[has-class("foo")]' data='<p class="foo">Second</p>'>]
>>> response.xpath('//p[has-class("foo", "bar-baz")]')
[<Selector xpath='//p[has-class("foo", "bar-baz")]' data='<p class="foo bar-baz">First</p>'>]
>>> response.xpath('//p[has-class("foo", "bar")]')
[]
So XPath ``//p[has-class("foo", "bar-baz")]`` is roughly equivalent to CSS
``p.foo.bar-baz``. Please note, that it is slower in most of the cases,

163
docs/topics/settings.rst
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@ -30,6 +30,8 @@ Python `import search path`_.
.. _import search path: https://docs.python.org/2/tutorial/modules.html#the-module-search-path
.. _populating-settings:
Populating the settings
=======================
@ -186,7 +188,6 @@ AWS_ENDPOINT_URL
Default: ``None``
Endpoint URL used for S3-like storage, for example Minio or s3.scality.
Only supported with ``botocore`` library.
.. setting:: AWS_USE_SSL
@ -197,7 +198,6 @@ Default: ``None``
Use this option if you want to disable SSL connection for communication with
S3 or S3-like storage. By default SSL will be used.
Only supported with ``botocore`` library.
.. setting:: AWS_VERIFY
@ -207,7 +207,7 @@ AWS_VERIFY
Default: ``None``
Verify SSL connection between Scrapy and S3 or S3-like storage. By default
SSL verification will occur. Only supported with ``botocore`` library.
SSL verification will occur.
.. setting:: AWS_REGION_NAME
@ -217,7 +217,6 @@ AWS_REGION_NAME
Default: ``None``
The name of the region associated with the AWS client.
Only supported with ``botocore`` library.
.. setting:: BOT_NAME
@ -227,8 +226,7 @@ BOT_NAME
Default: ``'scrapybot'``
The name of the bot implemented by this Scrapy project (also known as the
project name). This will be used to construct the User-Agent by default, and
also for logging.
project name). This name will be used for the logging too.
It's automatically populated with your project name when you create your
project with the :command:`startproject` command.
@ -378,6 +376,19 @@ Default: ``10000``
DNS in-memory cache size.
.. setting:: DNS_RESOLVER
DNS_RESOLVER
------------
Default: ``'scrapy.resolver.CachingThreadedResolver'``
The class to be used to resolve DNS names. The default ``scrapy.resolver.CachingThreadedResolver``
supports specifying a timeout for DNS requests via the :setting:`DNS_TIMEOUT` setting,
but works only with IPv4 addresses. Scrapy provides an alternative resolver,
``scrapy.resolver.CachingHostnameResolver``, which supports IPv4/IPv6 addresses but does not
take the :setting:`DNS_TIMEOUT` setting into account.
.. setting:: DNS_TIMEOUT
DNS_TIMEOUT
@ -438,9 +449,29 @@ or even enable client-side authentication (and various other things).
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 it accepts a ``method``
parameter at init (this is the ``OpenSSL.SSL`` method mapping
:setting:`DOWNLOADER_CLIENT_TLS_METHOD`).
If you do use a custom ContextFactory, make sure its ``__init__`` method
accepts a ``method`` parameter (this is the ``OpenSSL.SSL`` method mapping
:setting:`DOWNLOADER_CLIENT_TLS_METHOD`), a ``tls_verbose_logging``
parameter (``bool``) and a ``tls_ciphers`` parameter (see
:setting:`DOWNLOADER_CLIENT_TLS_CIPHERS`).
.. setting:: DOWNLOADER_CLIENT_TLS_CIPHERS
DOWNLOADER_CLIENT_TLS_CIPHERS
-----------------------------
Default: ``'DEFAULT'``
Use this setting to customize the TLS/SSL ciphers used by the default
HTTP/1.1 downloader.
The setting should contain a string in the `OpenSSL cipher list format`_,
these ciphers will be used as client ciphers. Changing this setting may be
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
.. setting:: DOWNLOADER_CLIENT_TLS_METHOD
@ -468,6 +499,20 @@ This setting must be one of these string values:
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
DOWNLOADER_CLIENT_TLS_VERBOSE_LOGGING
-------------------------------------
Default: ``False``
Setting this to ``True`` will enable DEBUG level messages about TLS connection
parameters after establishing HTTPS connections. The kind of information logged
depends on the versions of OpenSSL and pyOpenSSL.
This setting is only used for the default
:setting:`DOWNLOADER_CLIENTCONTEXTFACTORY`.
.. setting:: DOWNLOADER_MIDDLEWARES
DOWNLOADER_MIDDLEWARES
@ -538,6 +583,8 @@ amount of time between requests, but uses a random interval between 0.5 * :setti
When :setting:`CONCURRENT_REQUESTS_PER_IP` is non-zero, delays are enforced
per ip address instead of per domain.
.. _spider-download_delay-attribute:
You can also change this setting per spider by setting ``download_delay``
spider attribute.
@ -766,6 +813,7 @@ Default: ``True``
Whether or not to use passive mode when initiating FTP transfers.
.. reqmeta:: ftp_password
.. setting:: FTP_PASSWORD
FTP_PASSWORD
@ -784,6 +832,7 @@ in ``Request`` meta.
.. _RFC 1635: https://tools.ietf.org/html/rfc1635
.. reqmeta:: ftp_user
.. setting:: FTP_USER
FTP_USER
@ -865,7 +914,7 @@ LOG_FORMAT
Default: ``'%(asctime)s [%(name)s] %(levelname)s: %(message)s'``
String for formatting log messsages. Refer to the `Python logging documentation`_ for the whole list of available
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
@ -883,6 +932,15 @@ directives.
.. _Python datetime documentation: https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior
.. setting:: LOG_FORMATTER
LOG_FORMATTER
-------------
Default: :class:`scrapy.logformatter.LogFormatter`
The class to use for :ref:`formatting log messages <custom-log-formats>` for different actions.
.. setting:: LOG_LEVEL
LOG_LEVEL
@ -914,6 +972,16 @@ Default: ``False``
If ``True``, the logs will just contain the root path. If it is set to ``False``
then it displays the component responsible for the log output
.. setting:: LOGSTATS_INTERVAL
LOGSTATS_INTERVAL
-----------------
Default: ``60.0``
The interval (in seconds) between each logging printout of the stats
by :class:`~scrapy.extensions.logstats.LogStats`.
.. setting:: MEMDEBUG_ENABLED
MEMDEBUG_ENABLED
@ -1120,6 +1188,28 @@ If enabled, Scrapy will respect robots.txt policies. For more information see
this option is enabled by default in settings.py file generated
by ``scrapy startproject`` command.
.. setting:: ROBOTSTXT_PARSER
ROBOTSTXT_PARSER
----------------
Default: ``'scrapy.robotstxt.ProtegoRobotParser'``
The parser backend to use for parsing ``robots.txt`` files. For more information see
:ref:`topics-dlmw-robots`.
.. setting:: ROBOTSTXT_USER_AGENT
ROBOTSTXT_USER_AGENT
^^^^^^^^^^^^^^^^^^^^
Default: ``None``
The user agent string to use for matching in the robots.txt file. If ``None``,
the User-Agent header you are sending with the request or the
:setting:`USER_AGENT` setting (in that order) will be used for determining
the user agent to use in the robots.txt file.
.. setting:: SCHEDULER
SCHEDULER
@ -1172,9 +1262,25 @@ Type of in-memory queue used by scheduler. Other available type is:
SCHEDULER_PRIORITY_QUEUE
------------------------
Default: ``'queuelib.PriorityQueue'``
Default: ``'scrapy.pqueues.ScrapyPriorityQueue'``
Type of priority queue used by scheduler.
Type of priority queue used by the scheduler. Another available type is
``scrapy.pqueues.DownloaderAwarePriorityQueue``.
``scrapy.pqueues.DownloaderAwarePriorityQueue`` works better than
``scrapy.pqueues.ScrapyPriorityQueue`` when you crawl many different
domains in parallel. But currently ``scrapy.pqueues.DownloaderAwarePriorityQueue``
does not work together with :setting:`CONCURRENT_REQUESTS_PER_IP`.
.. setting:: SCRAPER_SLOT_MAX_ACTIVE_SIZE
SCRAPER_SLOT_MAX_ACTIVE_SIZE
----------------------------
Default: ``5_000_000``
Soft limit (in bytes) for response data being processed.
While the sum of the sizes of all responses being processed is above this value,
Scrapy does not process new requests.
.. setting:: SPIDER_CONTRACTS
@ -1199,7 +1305,7 @@ Default::
'scrapy.contracts.default.ScrapesContract': 3,
}
A dict containing the scrapy contracts enabled by default in Scrapy. You should
A dict containing the Scrapy contracts enabled by default in Scrapy. You should
never modify this setting in your project, modify :setting:`SPIDER_CONTRACTS`
instead. For more info see :ref:`topics-contracts`.
@ -1230,7 +1336,7 @@ SPIDER_LOADER_WARN_ONLY
Default: ``False``
By default, when scrapy tries to import spider classes from :setting:`SPIDER_MODULES`,
By default, when Scrapy tries to import spider classes from :setting:`SPIDER_MODULES`,
it will fail loudly if there is any ``ImportError`` exception.
But you can choose to silence this exception and turn it into a simple
warning by setting ``SPIDER_LOADER_WARN_ONLY = True``.
@ -1353,6 +1459,30 @@ command.
The project name must not conflict with the name of custom files or directories
in the ``project`` subdirectory.
.. setting:: TWISTED_REACTOR
TWISTED_REACTOR
---------------
Default: ``None``
Import path of a given Twisted reactor, for instance:
:class:`twisted.internet.asyncioreactor.AsyncioSelectorReactor`.
Scrapy will install this reactor if no other is installed yet, such as when
the ``scrapy`` CLI program is invoked or when using the
:class:`~scrapy.crawler.CrawlerProcess` class. If you are using the
:class:`~scrapy.crawler.CrawlerRunner` class, you need to install the correct
reactor manually. An exception will be raised if the installation fails.
The default value for this option is currently ``None``, which means that Scrapy
will not attempt to install any specific reactor, and the default one defined by
Twisted for the current platform will be used. This is to maintain backward
compatibility and avoid possible problems caused by using a non-default reactor.
For additional information, please see
:doc:`core/howto/choosing-reactor`.
.. setting:: URLLENGTH_LIMIT
@ -1373,7 +1503,10 @@ USER_AGENT
Default: ``"Scrapy/VERSION (+https://scrapy.org)"``
The default User-Agent to use when crawling, unless overridden.
The default User-Agent to use when crawling, unless overridden. This user agent is
also used by :class:`~scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware`
if :setting:`ROBOTSTXT_USER_AGENT` setting is ``None`` and
there is no overridding User-Agent header specified for the request.
Settings documented elsewhere:

79
docs/topics/shell.rst
View File

@ -31,7 +31,7 @@ for more info.
Scrapy also has support for `bpython`_, and will try to use it where `IPython`_
is unavailable.
Through scrapy's settings you can configure it to use any one of
Through Scrapy's settings you can configure it to use any one of
``ipython``, ``bpython`` or the standard ``python`` shell, regardless of which
are installed. This is done by setting the ``SCRAPY_PYTHON_SHELL`` environment
variable; or by defining it in your :ref:`scrapy.cfg <topics-config-settings>`::
@ -177,47 +177,46 @@ all start with the ``[s]`` prefix)::
>>>
After that, we can start playing with the objects::
After that, we can start playing with the objects:
>>> response.xpath('//title/text()').get()
'Scrapy | A Fast and Powerful Scraping and Web Crawling Framework'
>>> response.xpath('//title/text()').get()
'Scrapy | A Fast and Powerful Scraping and Web Crawling Framework'
>>> fetch("https://reddit.com")
>>> fetch("https://reddit.com")
>>> response.xpath('//title/text()').get()
'reddit: the front page of the internet'
>>> response.xpath('//title/text()').get()
'reddit: the front page of the internet'
>>> request = request.replace(method="POST")
>>> request = request.replace(method="POST")
>>> fetch(request)
>>> fetch(request)
>>> response.status
404
>>> response.status
404
>>> from pprint import pprint
>>> from pprint import pprint
>>> pprint(response.headers)
{'Accept-Ranges': ['bytes'],
'Cache-Control': ['max-age=0, must-revalidate'],
'Content-Type': ['text/html; charset=UTF-8'],
'Date': ['Thu, 08 Dec 2016 16:21:19 GMT'],
'Server': ['snooserv'],
'Set-Cookie': ['loid=KqNLou0V9SKMX4qb4n; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loidcreated=2016-12-08T16%3A21%3A19.445Z; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loid=vi0ZVe4NkxNWdlH7r7; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loidcreated=2016-12-08T16%3A21%3A19.459Z; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure'],
'Vary': ['accept-encoding'],
'Via': ['1.1 varnish'],
'X-Cache': ['MISS'],
'X-Cache-Hits': ['0'],
'X-Content-Type-Options': ['nosniff'],
'X-Frame-Options': ['SAMEORIGIN'],
'X-Moose': ['majestic'],
'X-Served-By': ['cache-cdg8730-CDG'],
'X-Timer': ['S1481214079.394283,VS0,VE159'],
'X-Ua-Compatible': ['IE=edge'],
'X-Xss-Protection': ['1; mode=block']}
>>>
>>> pprint(response.headers)
{'Accept-Ranges': ['bytes'],
'Cache-Control': ['max-age=0, must-revalidate'],
'Content-Type': ['text/html; charset=UTF-8'],
'Date': ['Thu, 08 Dec 2016 16:21:19 GMT'],
'Server': ['snooserv'],
'Set-Cookie': ['loid=KqNLou0V9SKMX4qb4n; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loidcreated=2016-12-08T16%3A21%3A19.445Z; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loid=vi0ZVe4NkxNWdlH7r7; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure',
'loidcreated=2016-12-08T16%3A21%3A19.459Z; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Sat, 08-Dec-2018 16:21:19 GMT; secure'],
'Vary': ['accept-encoding'],
'Via': ['1.1 varnish'],
'X-Cache': ['MISS'],
'X-Cache-Hits': ['0'],
'X-Content-Type-Options': ['nosniff'],
'X-Frame-Options': ['SAMEORIGIN'],
'X-Moose': ['majestic'],
'X-Served-By': ['cache-cdg8730-CDG'],
'X-Timer': ['S1481214079.394283,VS0,VE159'],
'X-Ua-Compatible': ['IE=edge'],
'X-Xss-Protection': ['1; mode=block']}
.. _topics-shell-inspect-response:
@ -263,16 +262,16 @@ When you run the spider, you will get something similar to this::
>>> response.url
'http://example.org'
Then, you can check if the extraction code is working::
Then, you can check if the extraction code is working:
>>> response.xpath('//h1[@class="fn"]')
[]
>>> response.xpath('//h1[@class="fn"]')
[]
Nope, it doesn't. So you can open the response in your web browser and see if
it's the response you were expecting::
it's the response you were expecting:
>>> view(response)
True
>>> view(response)
True
Finally you hit Ctrl-D (or Ctrl-Z in Windows) to exit the shell and resume the
crawling::

33
docs/topics/signals.rst
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@ -50,10 +50,10 @@ Here is a simple example showing how you can catch signals and perform some acti
Deferred signal handlers
========================
Some signals support returning `Twisted deferreds`_ from their handlers, see
the :ref:`topics-signals-ref` below to know which ones.
Some signals support returning :class:`~twisted.internet.defer.Deferred`
objects from their handlers, see the :ref:`topics-signals-ref` below to know
which ones.
.. _Twisted deferreds: https://twistedmatrix.com/documents/current/core/howto/defer.html
.. _topics-signals-ref:
@ -155,8 +155,8 @@ item_error
:param spider: the spider which raised the exception
:type spider: :class:`~scrapy.spiders.Spider` object
:param failure: the exception raised as a Twisted `Failure`_ object
:type failure: `Failure`_ object
:param failure: the exception raised
:type failure: twisted.python.failure.Failure
spider_closed
-------------
@ -236,8 +236,8 @@ spider_error
This signal does not support returning deferreds from their handlers.
:param failure: the exception raised as a Twisted `Failure`_ object
:type failure: `Failure`_ object
:param failure: the exception raised
:type failure: twisted.python.failure.Failure
:param response: the response being processed when the exception was raised
:type response: :class:`~scrapy.http.Response` object
@ -295,6 +295,23 @@ request_reached_downloader
:param spider: the spider that yielded the request
:type spider: :class:`~scrapy.spiders.Spider` object
request_left_downloader
-----------------------
.. signal:: request_left_downloader
.. function:: request_left_downloader(request, spider)
Sent when a :class:`~scrapy.http.Request` leaves the downloader, even in case of
failure.
This signal does not support returning deferreds from its handlers.
:param request: the request that reached the downloader
:type request: :class:`~scrapy.http.Request` object
:param spider: the spider that yielded the request
:type spider: :class:`~scrapy.spiders.Spider` object
response_received
-----------------
@ -333,5 +350,3 @@ response_downloaded
:param spider: the spider for which the response is intended
:type spider: :class:`~scrapy.spiders.Spider` object
.. _Failure: https://twistedmatrix.com/documents/current/api/twisted.python.failure.Failure.html

12
docs/topics/spider-middleware.rst
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@ -54,6 +54,8 @@ value. For example, if you want to disable the off-site middleware::
Finally, keep in mind that some middlewares may need to be enabled through a
particular setting. See each middleware documentation for more info.
.. _custom-spider-middleware:
Writing your own spider middleware
==================================
@ -82,7 +84,8 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
If it raises an exception, Scrapy won't bother calling any other spider
middleware :meth:`process_spider_input` and will call the request
errback. The output of the errback is chained back in the other
errback if there is one, otherwise it will start the :meth:`process_spider_exception`
chain. The output of the errback is chained back in the other
direction for :meth:`process_spider_output` to process it, or
:meth:`process_spider_exception` if it raised an exception.
@ -116,8 +119,8 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
.. method:: process_spider_exception(response, exception, spider)
This method is called when a spider or :meth:`process_spider_input`
method (from other spider middleware) raises an exception.
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
@ -129,7 +132,8 @@ object gives you access, for example, to the :ref:`settings <topics-settings>`.
exception reaches the engine (where it's logged and discarded).
If it returns an iterable the :meth:`process_spider_output` pipeline
kicks in, and no other :meth:`process_spider_exception` will be called.
kicks in, starting from the next spider middleware, and no other
:meth:`process_spider_exception` will be called.
:param response: the response being processed when the exception was
raised

40
docs/topics/spiders.rst
View File

@ -72,8 +72,6 @@ scrapy.Spider
spider that crawls ``mywebsite.com`` would often be called
``mywebsite``.
.. note:: In Python 2 this must be ASCII only.
.. attribute:: allowed_domains
An optional list of strings containing domains that this spider is
@ -374,16 +372,23 @@ CrawlSpider
Crawling rules
~~~~~~~~~~~~~~
.. class:: Rule(link_extractor, callback=None, cb_kwargs=None, follow=None, process_links=None, process_request=None)
.. autoclass:: Rule
``link_extractor`` is a :ref:`Link Extractor <topics-link-extractors>` object which
defines how links will be extracted from each crawled page.
defines how links will be extracted from each crawled page. Each produced link will
be used to generate a :class:`~scrapy.http.Request` object, which will contain the
link's text in its ``meta`` dictionary (under the ``link_text`` key).
If omitted, a default link extractor created with no arguments will be used,
resulting in all links being extracted.
``callback`` is a callable or a string (in which case a method from the spider
object with that name will be used) to be called for each link extracted with
the specified link_extractor. This callback receives a response as its first
argument and must return a list containing :class:`~scrapy.item.Item` and/or
:class:`~scrapy.http.Request` objects (or any subclass of them).
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
(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
@ -402,10 +407,18 @@ Crawling rules
of links extracted from each response using the specified ``link_extractor``.
This is mainly used for filtering purposes.
``process_request`` is a callable, or a string (in which case a method from
the spider object with that name will be used) which will be called with
every request extracted by this rule, and must return a request or None (to
filter out the request).
``process_request`` is a callable (or a string, in which case a method from
the spider object with that name will be used) which will be called for every
:class:`~scrapy.http.Request` extracted by this rule. This callable should
take said request as first argument and the :class:`~scrapy.http.Response`
from which the request originated as second argument. It must return a
``Request`` object or ``None`` (to filter out the request).
``errback`` is a callable or a string (in which case a method from the spider
object with that name will be used) to be called if any exception is
raised while processing a request generated by the rule.
It receives a :class:`Twisted Failure <twisted.python.failure.Failure>`
instance as first parameter.
CrawlSpider example
~~~~~~~~~~~~~~~~~~~
@ -436,6 +449,7 @@ Let's now take a look at an example CrawlSpider with rules::
item['id'] = response.xpath('//td[@id="item_id"]/text()').re(r'ID: (\d+)')
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']
return item
@ -655,7 +669,7 @@ SitemapSpider
.. attribute:: sitemap_follow
A list of regexes of sitemap that should be followed. This is is only
A list of regexes of sitemap that should be followed. This is only
for sites that use `Sitemap index files`_ that point to other sitemap
files.
@ -682,7 +696,7 @@ SitemapSpider
.. method:: sitemap_filter(entries)
This is a filter funtion that could be overridden to select sitemap entries
This is a filter function that could be overridden to select sitemap entries
based on their attributes.
For example::

15
docs/topics/stats.rst
View File

@ -57,15 +57,15 @@ Set stat value only if lower than previous::
stats.min_value('min_free_memory_percent', value)
Get stat value::
Get stat value:
>>> stats.get_value('custom_count')
1
>>> stats.get_value('custom_count')
1
Get all stats::
Get all stats:
>>> stats.get_stats()
{'custom_count': 1, 'start_time': datetime.datetime(2009, 7, 14, 21, 47, 28, 977139)}
>>> stats.get_stats()
{'custom_count': 1, 'start_time': datetime.datetime(2009, 7, 14, 21, 47, 28, 977139)}
Available Stats Collectors
==========================
@ -75,8 +75,7 @@ available in Scrapy which extend the basic Stats Collector. You can select
which Stats Collector to use through the :setting:`STATS_CLASS` setting. The
default Stats Collector used is the :class:`MemoryStatsCollector`.
.. module:: scrapy.statscollectors
:synopsis: Stats Collectors
.. currentmodule:: scrapy.statscollectors
MemoryStatsCollector
--------------------

9
docs/topics/telnetconsole.rst
View File

@ -1,12 +1,11 @@
.. currentmodule:: scrapy.extensions.telnet
.. _topics-telnetconsole:
==============
Telnet Console
==============
.. module:: scrapy.extensions.telnet
:synopsis: The Telnet Console
Scrapy comes with a built-in telnet console for inspecting and controlling a
Scrapy running process. The telnet console is just a regular python shell
running inside the Scrapy process, so you can do literally anything from it.
@ -45,11 +44,11 @@ the console you need to type::
>>>
By default Username is ``scrapy`` and Password is autogenerated. The
autogenerated Password can be seen on scrapy logs like the example bellow::
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
Default Username and Password can be overriden by the settings
Default Username and Password can be overridden by the settings
:setting:`TELNETCONSOLE_USERNAME` and :setting:`TELNETCONSOLE_PASSWORD`.
.. warning::

41
docs/topics/ubuntu.rst
View File

@ -1,41 +0,0 @@
:orphan: Ubuntu packages are obsolete
.. _topics-ubuntu:
===============
Ubuntu packages
===============
.. versionadded:: 0.10
`Scrapinghub`_ publishes apt-gettable packages which are generally fresher than
those in Ubuntu, and more stable too since they're continuously built from
`GitHub repo`_ (master & stable branches) and so they contain the latest bug
fixes.
.. caution:: These packages are currently not updated and may not work on
Ubuntu 16.04 and above, see :issue:`2076` and :issue:`2137`.
To use the packages:
1. Import the GPG key used to sign Scrapy packages into APT keyring::
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 627220E7
2. Create ``/etc/apt/sources.list.d/scrapy.list`` file using the following command::
echo 'deb http://archive.scrapy.org/ubuntu scrapy main' | sudo tee /etc/apt/sources.list.d/scrapy.list
3. Update package lists and install the scrapy package:
.. parsed-literal::
sudo apt-get update && sudo apt-get install scrapy
.. note:: Repeat step 3 if you are trying to upgrade Scrapy.
.. warning:: ``python-scrapy`` is a different package provided by official debian
repositories, it's very outdated and it isn't supported by Scrapy team.
.. _Scrapinghub: https://scrapinghub.com/
.. _GitHub repo: https://github.com/scrapy/scrapy

1
extras/qps-bench-server.py
View File

@ -1,5 +1,4 @@
#!/usr/bin/env python
from __future__ import print_function
from time import time
from collections import deque
from twisted.web.server import Site, NOT_DONE_YET

226
extras/scrapy_zsh_completion
View File

@ -1,25 +1,213 @@
#compdef scrapy
# zsh completion for the Scrapy command-line tool
_scrapy() {
local curcontext="$curcontext" cmd spiders
local context state state_descr line
local ret=1
typeset -A opt_args
cmd=$words[2]
case "$cmd" in
crawl|edit|check)
spiders=$(scrapy list 2>/dev/null) || spiders=""
if [[ -n "$spiders" ]]; then
compadd `echo $spiders`
fi
;;
*)
if [[ CURRENT -eq 2 ]]; then
_arguments '*: :(check crawl edit fetch genspider list parse runspider settings shell startproject version view)'
fi
;;
_arguments \
"(- 1 *)"{-h,--help}"[Help]" \
"1: :->command" \
"*:: :->args" && ret=0
case $state in
command)
_scrapy_cmds
;;
args)
case $words[1] in
bench)
_scrapy_glb_opts
;;
fetch)
local options=(
'--headers[print response HTTP headers instead of body]'
'--no-redirect[do not handle HTTP 3xx status codes and print response as-is]'
'--spider[use this spider]:spider:_scrapy_spiders'
'1::URL:_httpie_urls'
)
_scrapy_glb_opts $options
;;
genspider)
local options=(
{-l,--list}'[List available templates]'
{-e,--edit}'[Edit spider after creating it]'
'--force[If the spider already exists, overwrite it with the template]'
{-d,--dump=}'[Dump template to standard output]:template:(basic crawl csvfeed xmlfeed)'
{-t,--template=}'[Uses a custom template]:template:(basic crawl csvfeed xmlfeed)'
'1:name:(NAME)'
'2:domain:_httpie_urls'
)
_scrapy_glb_opts $options
;;
runspider)
local options=(
{-o,--output}'[dump scraped items into FILE (use - for stdout)]:file:_files'
{-t,--output-format}'[format to use for dumping items with -o]:format:(FORMAT)'
'*-a[set spider argument (may be repeated)]:value pair:(NAME=VALUE)'
'1:spider file:_files -g \*.py'
)
_scrapy_glb_opts $options
;;
settings)
local options=(
'--get=[print raw setting value]:option:(SETTING)'
'--getbool=[print setting value, interpreted as a boolean]:option:(SETTING)'
'--getint=[print setting value, interpreted as an integer]:option:(SETTING)'
'--getfloat=[print setting value, interpreted as a float]:option:(SETTING)'
'--getlist=[print setting value, interpreted as a list]:option:(SETTING)'
)
_scrapy_glb_opts $options
;;
shell)
local options=(
'-c[evaluate the code in the shell, print the result and exit]:code:(CODE)'
'--no-redirect[do not handle HTTP 3xx status codes and print response as-is]'
'--spider[use this spider]:spider:_scrapy_spiders'
'::file:_files -g \*.html'
'::URL:_httpie_urls'
)
_scrapy_glb_opts $options
;;
startproject)
local options=(
'1:name:(NAME)'
'2:dir:_dir_list'
)
_scrapy_glb_opts $options
;;
version)
local options=(
{-v,--verbose}'[also display twisted/python/platform info (useful for bug reports)]'
)
_scrapy_glb_opts $options
;;
view)
local options=(
'--no-redirect[do not handle HTTP 3xx status codes and print response as-is]'
'--spider[use this spider]:spider:_scrapy_spiders'
'1:URL:_httpie_urls'
)
_scrapy_glb_opts $options
;;
check)
local options=(
'(- 1 *)'{-l,--list}'[only list contracts, without checking them]'
{-v,--verbose}'[print contract tests for all spiders]'
'1:spider:_scrapy_spiders'
)
_scrapy_glb_opts $options
;;
crawl)
local options=(
{-o,--output}'[dump scraped items into FILE (use - for stdout)]:file:_files'
{-t,--output-format}'[format to use for dumping items with -o]:format:(FORMAT)'
'*-a[set spider argument (may be repeated)]:value pair:(NAME=VALUE)'
'1:spider:_scrapy_spiders'
)
_scrapy_glb_opts $options
;;
edit)
local options=(
'1:spider:_scrapy_spiders'
)
_scrapy_glb_opts $options
;;
list)
_scrapy_glb_opts
;;
parse)
local options=(
'*-a[set spider argument (may be repeated)]:value pair:(NAME=VALUE)'
'--spider[use this spider without looking for one]:spider:_scrapy_spiders'
'--pipelines[process items through pipelines]'
"--nolinks[don't show links to follow (extracted requests)]"
"--noitems[don't show scraped items]"
'--nocolour[avoid using pygments to colorize the output]'
{-r,--rules}'[use CrawlSpider rules to discover the callback]'
{-c,--callback=}'[use this callback for parsing, instead looking for a callback]:callback:(CALLBACK)'
{-m,--meta=}'[inject extra meta into the Request, it must be a valid raw json string]:meta:(META)'
'--cbkwargs=[inject extra callback kwargs into the Request, it must be a valid raw json string]:arguments:(CBKWARGS)'
{-d,--depth=}'[maximum depth for parsing requests (default: 1)]:depth:(DEPTH)'
{-v,--verbose}'[print each depth level one by one]'
'1:URL:_httpie_urls'
)
_scrapy_glb_opts $options
;;
esac
;;
esac
return ret
}
_scrapy
_scrapy_cmds() {
local -a commands project_commands
commands=(
'bench:Run quick benchmark test'
'fetch:Fetch a URL using the Scrapy downloader'
'genspider:Generate new spider using pre-defined templates'
'runspider:Run a self-contained spider (without creating a project)'
'settings:Get settings values'
'shell:Interactive scraping console'
'startproject:Create new project'
'version:Print Scrapy version'
'view:Open URL in browser, as seen by Scrapy'
)
project_commands=(
'check:Check spider contracts'
'crawl:Run a spider'
'edit:Edit spider'
'list:List available spiders'
'parse:Parse URL (using its spider) and print the results'
)
if [[ $(scrapy -h | grep -s "no active project") == "" ]]; then
commands=(${commands[@]} ${project_commands[@]})
fi
_describe -t common-commands 'common commands' commands
}
_scrapy_glb_opts() {
local -a options
options=(
'(- *)'{-h,--help}'[show this help message and exit]'
'(--nolog)--logfile=[log file. if omitted stderr will be used]:file:_files'
'--pidfile=[write process ID to FILE]:file:_files'
'--profile=[write python cProfile stats to FILE]:file:_files'
'(--nolog)'{-L,--loglevel=}'[log level (default: INFO)]:log level:(DEBUG INFO WARN ERROR)'
'(-L --loglevel --logfile)--nolog[disable logging completely]'
'--pdb[enable pdb on failure]'
'*'{-s,--set=}'[set/override setting (may be repeated)]:value pair:(NAME=VALUE)'
)
options=(${options[@]} "$@")
_arguments $options
}
_httpie_urls() {
local ret=1
if ! [[ -prefix [-+.a-z0-9]#:// ]]; then
local expl
compset -S '[^:/]*' && compstate[to_end]=''
_wanted url-schemas expl 'URL schema' compadd -S '' http:// https:// && ret=0
else
_urls && ret=0
fi
return $ret
}
_scrapy_spiders() {
local ret=1
if [[ $(scrapy -h | grep -s "no active project") == "" ]]; then
compadd -S '' $(scrapy list) && ret=0
else
compadd -S '' SPIDER && ret=0
fi
return $ret
}
_scrapy $@

250
pytest.ini
View File

@ -2,5 +2,253 @@
usefixtures = chdir
python_files=test_*.py __init__.py
python_classes=
addopts = --doctest-modules --assert=plain
addopts =
--assert=plain
--doctest-modules
--ignore=docs/_ext
--ignore=docs/conf.py
--ignore=docs/news.rst
--ignore=docs/topics/dynamic-content.rst
--ignore=docs/topics/items.rst
--ignore=docs/topics/leaks.rst
--ignore=docs/topics/loaders.rst
--ignore=docs/topics/selectors.rst
--ignore=docs/topics/shell.rst
--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 E502
scrapy/commands/parse.py E128 E501 E731 E226
scrapy/commands/runspider.py E501
scrapy/commands/settings.py E128
scrapy/commands/shell.py E128 E501 E502
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 E306 E502
scrapy/core/scheduler.py E501
scrapy/core/scraper.py E501 E306 E128 W504
scrapy/core/spidermw.py E501 E731 E126 E226
scrapy/core/downloader/__init__.py E501
scrapy/core/downloader/contextfactory.py E501 E128 E126
scrapy/core/downloader/middleware.py E501 E502
scrapy/core/downloader/tls.py E501 E305 E241
scrapy/core/downloader/webclient.py E731 E501 E128 E126 E226
scrapy/core/downloader/handlers/__init__.py E501
scrapy/core/downloader/handlers/ftp.py E501 E305 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 E226
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 E303
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 E226
# 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 E266
scrapy/pipelines/images.py E265 E501
scrapy/pipelines/media.py E125 E501 E266
# 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 E226
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/console.py E306 E305
scrapy/utils/datatypes.py E501 E226
scrapy/utils/decorators.py E501
scrapy/utils/defer.py E501 E128
scrapy/utils/deprecate.py E128 E501 E127 E502
scrapy/utils/gz.py E305 E501 W504
scrapy/utils/http.py F403 E226
scrapy/utils/httpobj.py E501
scrapy/utils/iterators.py E501 E701
scrapy/utils/log.py E128 E501
scrapy/utils/markup.py F403
scrapy/utils/misc.py E501 E226
scrapy/utils/multipart.py F403
scrapy/utils/project.py E501
scrapy/utils/python.py E501
scrapy/utils/reactor.py E226 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 E271 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 E202
scrapy/exceptions.py E501
scrapy/exporters.py E501 E226
scrapy/interfaces.py E501
scrapy/item.py E501 E128
scrapy/link.py E501
scrapy/logformatter.py E501
scrapy/mail.py E402 E128 E501 E502
scrapy/middleware.py E128 E501
scrapy/pqueues.py E501
scrapy/resolver.py E501
scrapy/responsetypes.py E128 E501 E305
scrapy/robotstxt.py E501
scrapy/shell.py E501
scrapy/signalmanager.py E501
scrapy/spiderloader.py E225 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 E226
tests/spiders.py E501 E127
tests/test_closespider.py E501 E127
tests/test_command_fetch.py E501
tests/test_command_parse.py E501 E128 E303 E226
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 E265
tests/test_crawler.py F841 E306 E501
tests/test_dependencies.py F841 E501 E305
tests/test_downloader_handlers.py E124 E127 E128 E225 E265 E501 E701 E126 E226 E123
tests/test_downloadermiddleware.py E501
tests/test_downloadermiddleware_ajaxcrawlable.py E501
tests/test_downloadermiddleware_cookies.py E731 E741 E501 E128 E303 E265 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 E305
tests/test_downloadermiddleware_httpcompression.py E501 E251 E126 E123
tests/test_downloadermiddleware_httpproxy.py E501 E128
tests/test_downloadermiddleware_redirect.py E501 E303 E128 E306 E127 E305
tests/test_downloadermiddleware_retry.py E501 E128 E251 E303 E126
tests/test_downloadermiddleware_robotstxt.py E501
tests/test_downloadermiddleware_stats.py E501
tests/test_dupefilters.py E221 E501 E741 E128 E124
tests/test_engine.py E401 E501 E128
tests/test_exporters.py E501 E731 E306 E128 E124
tests/test_extension_telnet.py F841
tests/test_feedexport.py E501 F841 E241
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 E301 E128 E265
tests/test_item.py E701 E128 F841 E306
tests/test_link.py E501
tests/test_linkextractors.py E501 E128 E124
tests/test_loader.py E501 E731 E303 E741 E128 E117 E241
tests/test_logformatter.py E128 E501 E122
tests/test_mail.py E128 E501 E305
tests/test_middleware.py E501 E128
tests/test_pipeline_crawl.py E131 E501 E128 E126
tests/test_pipeline_files.py E501 E303 E272 E226
tests/test_pipeline_images.py F841 E501 E303
tests/test_pipeline_media.py E501 E741 E731 E128 E306 E502
tests/test_proxy_connect.py E501 E741
tests/test_request_cb_kwargs.py E501
tests/test_responsetypes.py E501 E305
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 E226
tests/test_spidermiddleware_httperror.py E128 E501 E127 E121
tests/test_spidermiddleware_offsite.py E501 E128 E111
tests/test_spidermiddleware_output_chain.py E501 E226
tests/test_spidermiddleware_referer.py E501 F841 E125 E201 E124 E501 E241 E121
tests/test_squeues.py E501 E701 E741
tests/test_utils_asyncio.py E501
tests/test_utils_conf.py E501 E303 E128
tests/test_utils_curl.py E501
tests/test_utils_datatypes.py E402 E501 E305
tests/test_utils_defer.py E306 E501 F841 E226
tests/test_utils_deprecate.py F841 E306 E501
tests/test_utils_http.py E501 E128 W504
tests/test_utils_iterators.py E501 E128 E129 E303 E241
tests/test_utils_log.py E741 E226
tests/test_utils_python.py E501 E303 E731 E701 E305
tests/test_utils_reqser.py E501 E128
tests/test_utils_request.py E501 E128 E305
tests/test_utils_response.py E501
tests/test_utils_signal.py E741 F841 E731 E226
tests/test_utils_sitemap.py E128 E501 E124
tests/test_utils_spider.py E305
tests/test_utils_template.py E305
tests/test_utils_url.py E501 E127 E305 E211 E125 E501 E226 E241 E126 E123
tests/test_webclient.py E501 E128 E122 E303 E402 E306 E226 E241 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

10
requirements-py2.txt
View File

@ -1,10 +0,0 @@
Twisted>=13.1.0
lxml
pyOpenSSL
cssselect>=0.9
queuelib
w3lib>=1.17.0
six>=1.5.2
PyDispatcher>=2.0.5
parsel>=1.5
service_identity

10
requirements-py3.txt
View File

@ -1,10 +0,0 @@
Twisted>=17.9.0
lxml>=3.2.4
pyOpenSSL>=0.13.1
cssselect>=0.9
queuelib>=1.1.1
w3lib>=1.17.0
six>=1.5.2
PyDispatcher>=2.0.5
parsel>=1.5
service_identity

2
scrapy/VERSION
View File

@ -1 +1 @@
1.6.0
1.8.0

6
scrapy/__init__.py
View File

@ -14,8 +14,8 @@ del pkgutil
# Check minimum required Python version
import sys
if sys.version_info < (2, 7):
print("Scrapy %s requires Python 2.7" % __version__)
if sys.version_info < (3, 5):
print("Scrapy %s requires Python 3.5" % __version__)
sys.exit(1)
# Ignore noisy twisted deprecation warnings
@ -24,7 +24,7 @@ warnings.filterwarnings('ignore', category=DeprecationWarning, module='twisted')
del warnings
# Apply monkey patches to fix issues in external libraries
from . import _monkeypatches
from scrapy import _monkeypatches
del _monkeypatches
from twisted import version as _txv

16
scrapy/_monkeypatches.py
View File

@ -1,18 +1,4 @@
import sys
from six.moves import copyreg
if sys.version_info[0] == 2:
from urlparse import urlparse
# workaround for https://bugs.python.org/issue7904 - Python < 2.7
if urlparse('s3://bucket/key').netloc != 'bucket':
from urlparse import uses_netloc
uses_netloc.append('s3')
# workaround for https://bugs.python.org/issue9374 - Python < 2.7.4
if urlparse('s3://bucket/key?key=value').query != 'key=value':
from urlparse import uses_query
uses_query.append('s3')
import copyreg
# Undo what Twisted's perspective broker adds to pickle register

44
scrapy/cmdline.py
View File

@ -1,5 +1,5 @@
from __future__ import print_function
import sys, os
import sys
import os
import optparse
import cProfile
import inspect
@ -14,6 +14,7 @@ from scrapy.utils.project import inside_project, get_project_settings
from scrapy.utils.python import garbage_collect
from scrapy.settings.deprecated import check_deprecated_settings
def _iter_command_classes(module_name):
# TODO: add `name` attribute to commands and and merge this function with
# scrapy.utils.spider.iter_spider_classes
@ -25,6 +26,7 @@ def _iter_command_classes(module_name):
not obj == ScrapyCommand:
yield obj
def _get_commands_from_module(module, inproject):
d = {}
for cmd in _iter_command_classes(module):
@ -33,6 +35,7 @@ def _get_commands_from_module(module, inproject):
d[cmdname] = cmd()
return d
def _get_commands_from_entry_points(inproject, group='scrapy.commands'):
cmds = {}
for entry_point in pkg_resources.iter_entry_points(group):
@ -43,6 +46,7 @@ def _get_commands_from_entry_points(inproject, group='scrapy.commands'):
raise Exception("Invalid entry point %s" % entry_point.name)
return cmds
def _get_commands_dict(settings, inproject):
cmds = _get_commands_from_module('scrapy.commands', inproject)
cmds.update(_get_commands_from_entry_points(inproject))
@ -51,6 +55,7 @@ def _get_commands_dict(settings, inproject):
cmds.update(_get_commands_from_module(cmds_module, inproject))
return cmds
def _pop_command_name(argv):
i = 0
for arg in argv[1:]:
@ -59,13 +64,15 @@ def _pop_command_name(argv):
return arg
i += 1
def _print_header(settings, inproject):
if inproject:
print("Scrapy %s - project: %s\n" % (scrapy.__version__, \
settings['BOT_NAME']))
print("Scrapy %s - project: %s\n" % (scrapy.__version__,
settings['BOT_NAME']))
else:
print("Scrapy %s - no active project\n" % scrapy.__version__)
def _print_commands(settings, inproject):
_print_header(settings, inproject)
print("Usage:")
@ -80,11 +87,13 @@ def _print_commands(settings, inproject):
print()
print('Use "scrapy <command> -h" to see more info about a command')
def _print_unknown_command(settings, cmdname, inproject):
_print_header(settings, inproject)
print("Unknown command: %s\n" % cmdname)
print('Use "scrapy" to see available commands')
def _run_print_help(parser, func, *a, **kw):
try:
func(*a, **kw)
@ -95,41 +104,27 @@ def _run_print_help(parser, func, *a, **kw):
parser.print_help()
sys.exit(2)
def execute(argv=None, settings=None):
if argv is None:
argv = sys.argv
# --- backward compatibility for scrapy.conf.settings singleton ---
if settings is None and 'scrapy.conf' in sys.modules:
from scrapy import conf
if hasattr(conf, 'settings'):
settings = conf.settings
# ------------------------------------------------------------------
if settings is None:
settings = get_project_settings()
# set EDITOR from environment if available
try:
editor = os.environ['EDITOR']
except KeyError: pass
except KeyError:
pass
else:
settings['EDITOR'] = editor
check_deprecated_settings(settings)
# --- backward compatibility for scrapy.conf.settings singleton ---
import warnings
from scrapy.exceptions import ScrapyDeprecationWarning
with warnings.catch_warnings():
warnings.simplefilter("ignore", ScrapyDeprecationWarning)
from scrapy import conf
conf.settings = settings
# ------------------------------------------------------------------
inproject = inside_project()
cmds = _get_commands_dict(settings, inproject)
cmdname = _pop_command_name(argv)
parser = optparse.OptionParser(formatter=optparse.TitledHelpFormatter(), \
conflict_handler='resolve')
parser = optparse.OptionParser(formatter=optparse.TitledHelpFormatter(),
conflict_handler='resolve')
if not cmdname:
_print_commands(settings, inproject)
sys.exit(0)
@ -150,12 +145,14 @@ def execute(argv=None, settings=None):
_run_print_help(parser, _run_command, cmd, args, opts)
sys.exit(cmd.exitcode)
def _run_command(cmd, args, opts):
if opts.profile:
_run_command_profiled(cmd, args, opts)
else:
cmd.run(args, opts)
def _run_command_profiled(cmd, args, opts):
if opts.profile:
sys.stderr.write("scrapy: writing cProfile stats to %r\n" % opts.profile)
@ -165,6 +162,7 @@ def _run_command_profiled(cmd, args, opts):
if opts.profile:
p.dump_stats(opts.profile)
if __name__ == '__main__':
try:
execute()

2
scrapy/commands/__init__.py
View File

@ -47,7 +47,7 @@ class ScrapyCommand(object):
def help(self):
"""An extensive help for the command. It will be shown when using the
"help" command. It can contain newlines, since not post-formatting will
"help" command. It can contain newlines, since no post-formatting will
be applied to its contents.
"""
return self.long_desc()

3
scrapy/commands/bench.py
View File

@ -1,8 +1,7 @@
import sys
import time
import subprocess
from six.moves.urllib.parse import urlencode
from urllib.parse import urlencode
import scrapy
from scrapy.commands import ScrapyCommand

24
scrapy/commands/check.py
View File

@ -1,12 +1,10 @@
from __future__ import print_function
import time
import sys
from collections import defaultdict
from unittest import TextTestRunner, TextTestResult as _TextTestResult
from scrapy.commands import ScrapyCommand
from scrapy.contracts import ContractsManager
from scrapy.utils.misc import load_object
from scrapy.utils.misc import load_object, set_environ
from scrapy.utils.conf import build_component_list
@ -68,16 +66,17 @@ class Command(ScrapyCommand):
spider_loader = self.crawler_process.spider_loader
for spidername in args or spider_loader.list():
spidercls = spider_loader.load(spidername)
spidercls.start_requests = lambda s: conman.from_spider(s, result)
with set_environ(SCRAPY_CHECK='true'):
for spidername in args or spider_loader.list():
spidercls = spider_loader.load(spidername)
spidercls.start_requests = lambda s: conman.from_spider(s, result)
tested_methods = conman.tested_methods_from_spidercls(spidercls)
if opts.list:
for method in tested_methods:
contract_reqs[spidercls.name].append(method)
elif tested_methods:
self.crawler_process.crawl(spidercls)
tested_methods = conman.tested_methods_from_spidercls(spidercls)
if opts.list:
for method in tested_methods:
contract_reqs[spidercls.name].append(method)
elif tested_methods:
self.crawler_process.crawl(spidercls)
# start checks
if opts.list:
@ -95,4 +94,3 @@ class Command(ScrapyCommand):
result.printErrors()
result.printSummary(start, stop)
self.exitcode = int(not result.wasSuccessful())

18
scrapy/commands/fetch.py
View File

@ -1,5 +1,4 @@
from __future__ import print_function
import sys, six
import sys
from w3lib.url import is_url
from scrapy.commands import ScrapyCommand
@ -8,6 +7,7 @@ from scrapy.exceptions import UsageError
from scrapy.utils.datatypes import SequenceExclude
from scrapy.utils.spider import spidercls_for_request, DefaultSpider
class Command(ScrapyCommand):
requires_project = False
@ -24,12 +24,11 @@ class Command(ScrapyCommand):
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("--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")
def _print_headers(self, headers, prefix):
for key, values in headers.items():
@ -45,8 +44,7 @@ class Command(ScrapyCommand):
self._print_bytes(response.body)
def _print_bytes(self, bytes_):
bytes_writer = sys.stdout if six.PY2 else sys.stdout.buffer
bytes_writer.write(bytes_ + b'\n')
sys.stdout.buffer.write(bytes_ + b'\n')
def run(self, args, opts):
if len(args) != 1 or not is_url(args[0]):

1
scrapy/commands/genspider.py
View File

@ -1,4 +1,3 @@
from __future__ import print_function
import os
import shutil
import string

2
scrapy/commands/list.py
View File

@ -1,6 +1,6 @@
from __future__ import print_function
from scrapy.commands import ScrapyCommand
class Command(ScrapyCommand):
requires_project = True

53
scrapy/commands/parse.py
View File

@ -1,4 +1,3 @@
from __future__ import print_function
import json
import logging
@ -51,18 +50,21 @@ class Command(ScrapyCommand):
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")
parser.add_option("--cbkwargs", dest="cbkwargs",
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]")
parser.add_option("-v", "--verbose", dest="verbose", action="store_true",
help="print each depth level one by one")
@property
def max_level(self):
levels = list(self.items.keys()) + list(self.requests.keys())
if not levels:
return 0
return max(levels)
max_items, max_requests = 0, 0
if self.items:
max_items = max(self.items)
if self.requests:
max_requests = max(self.requests)
return max(max_items, max_requests)
def add_items(self, lvl, new_items):
old_items = self.items.get(lvl, [])
@ -83,9 +85,8 @@ class Command(ScrapyCommand):
def print_requests(self, lvl=None, colour=True):
if lvl is None:
levels = list(self.requests.keys())
if levels:
requests = self.requests[max(levels)]
if self.requests:
requests = self.requests[max(self.requests)]
else:
requests = []
else:
@ -111,10 +112,11 @@ class Command(ScrapyCommand):
if not opts.nolinks:
self.print_requests(colour=colour)
def run_callback(self, response, cb):
def run_callback(self, response, callback, cb_kwargs=None):
cb_kwargs = cb_kwargs or {}
items, requests = [], []
for x in iterate_spider_output(cb(response)):
for x in iterate_spider_output(callback(response, **cb_kwargs)):
if isinstance(x, (BaseItem, dict)):
items.append(x)
elif isinstance(x, Request):
@ -142,8 +144,7 @@ class Command(ScrapyCommand):
else:
self.spidercls = spidercls_for_request(spider_loader, Request(url))
if not self.spidercls:
logger.error('Unable to find spider for: %(url)s',
{'url': url})
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)
@ -160,7 +161,7 @@ class Command(ScrapyCommand):
{'url': url})
def prepare_request(self, spider, request, opts):
def callback(response):
def callback(response, **cb_kwargs):
# memorize first request
if not self.first_response:
self.first_response = response
@ -175,7 +176,7 @@ class Command(ScrapyCommand):
if not cb:
logger.error('Cannot find a rule that matches %(url)r in spider: %(spider)s',
{'url': response.url, 'spider': spider.name})
{'url': response.url, 'spider': spider.name})
return
else:
cb = 'parse'
@ -192,7 +193,7 @@ class Command(ScrapyCommand):
# parse items and requests
depth = response.meta['_depth']
items, requests = self.run_callback(response, cb)
items, requests = self.run_callback(response, cb, cb_kwargs)
if opts.pipelines:
itemproc = self.pcrawler.engine.scraper.itemproc
for item in items:
@ -207,10 +208,14 @@ class Command(ScrapyCommand):
req.callback = callback
return requests
#update request meta if any extra meta was passed through the --meta/-m opts.
# update request meta if any extra meta was passed through the --meta/-m opts.
if opts.meta:
request.meta.update(opts.meta)
# update cb_kwargs if any extra values were was passed through the --cbkwargs option.
if opts.cbkwargs:
request.cb_kwargs.update(opts.cbkwargs)
request.meta['_depth'] = 1
request.meta['_callback'] = request.callback
request.callback = callback
@ -221,23 +226,29 @@ class Command(ScrapyCommand):
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:
opts.meta = json.loads(opts.meta)
except ValueError:
raise UsageError("Invalid -m/--meta value, pass a valid json string to -m or --meta. " \
"Example: --meta='{\"foo\" : \"bar\"}'", print_help=False)
raise UsageError("Invalid -m/--meta value, pass a valid json string to -m or --meta. "
"Example: --meta='{\"foo\" : \"bar\"}'", print_help=False)
def process_request_cb_kwargs(self, opts):
if opts.cbkwargs:
try:
opts.cbkwargs = json.loads(opts.cbkwargs)
except ValueError:
raise UsageError("Invalid --cbkwargs value, pass a valid json string to --cbkwargs. "
"Example: --cbkwargs='{\"foo\" : \"bar\"}'", print_help=False)
def run(self, args, opts):
# parse arguments

5
scrapy/commands/runspider.py
View File

@ -60,14 +60,13 @@ class Command(ScrapyCommand):
else:
self.settings.set('FEED_URI', opts.output, priority='cmdline')
feed_exporters = without_none_values(self.settings.getwithbase('FEED_EXPORTERS'))
valid_output_formats = feed_exporters.keys()
if not opts.output_format:
opts.output_format = os.path.splitext(opts.output)[1].replace(".", "")
if opts.output_format not in valid_output_formats:
if opts.output_format not in feed_exporters:
raise UsageError("Unrecognized output format '%s', set one"
" using the '-t' switch or as a file extension"
" from the supported list %s" % (opts.output_format,
tuple(valid_output_formats)))
tuple(feed_exporters)))
self.settings.set('FEED_FORMAT', opts.output_format, priority='cmdline')
def run(self, args, opts):

2
scrapy/commands/settings.py
View File

@ -1,9 +1,9 @@
from __future__ import print_function
import json
from scrapy.commands import ScrapyCommand
from scrapy.settings import BaseSettings
class Command(ScrapyCommand):
requires_project = False

2
scrapy/commands/shell.py
View File

@ -6,8 +6,8 @@ See documentation in docs/topics/shell.rst
from threading import Thread
from scrapy.commands import ScrapyCommand
from scrapy.shell import Shell
from scrapy.http import Request
from scrapy.shell import Shell
from scrapy.utils.spider import spidercls_for_request, DefaultSpider
from scrapy.utils.url import guess_scheme

6
scrapy/commands/startproject.py
View File

@ -1,4 +1,3 @@
from __future__ import print_function
import re
import os
import string
@ -44,8 +43,8 @@ class Command(ScrapyCommand):
return False
if not re.search(r'^[_a-zA-Z]\w*$', project_name):
print('Error: Project names must begin with a letter and contain'\
' only\nletters, numbers and underscores')
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)
else:
@ -119,4 +118,3 @@ class Command(ScrapyCommand):
_templates_base_dir = self.settings['TEMPLATES_DIR'] or \
join(scrapy.__path__[0], 'templates')
return join(_templates_base_dir, 'project')

3
scrapy/commands/version.py
View File

@ -1,5 +1,3 @@
from __future__ import print_function
import scrapy
from scrapy.commands import ScrapyCommand
from scrapy.utils.versions import scrapy_components_versions
@ -30,4 +28,3 @@ class Command(ScrapyCommand):
print(patt % (name, version))
else:
print("Scrapy %s" % scrapy.__version__)

3
scrapy/commands/view.py
View File

@ -1,6 +1,7 @@
from scrapy.commands import fetch, ScrapyCommand
from scrapy.commands import fetch
from scrapy.utils.response import open_in_browser
class Command(fetch.Command):
def short_desc(self):

13
scrapy/conf.py
View File

@ -1,13 +0,0 @@
# This module is kept for backward compatibility, so users can import
# scrapy.conf.settings and get the settings they expect
import sys
if 'scrapy.cmdline' not in sys.modules:
from scrapy.utils.project import get_project_settings
settings = get_project_settings()
import warnings
from scrapy.exceptions import ScrapyDeprecationWarning
warnings.warn("Module `scrapy.conf` is deprecated, use `crawler.settings` attribute instead",
ScrapyDeprecationWarning, stacklevel=2)

14
scrapy/contracts/__init__.py
View File

@ -90,11 +90,11 @@ class ContractsManager(object):
cb = request.callback
@wraps(cb)
def cb_wrapper(response):
def cb_wrapper(response, **cb_kwargs):
try:
output = cb(response)
output = cb(response, **cb_kwargs)
output = list(iterate_spider_output(output))
except:
except Exception:
case = _create_testcase(method, 'callback')
results.addError(case, sys.exc_info())
@ -121,7 +121,7 @@ class Contract(object):
cb = request.callback
@wraps(cb)
def wrapper(response):
def wrapper(response, **cb_kwargs):
try:
results.startTest(self.testcase_pre)
self.pre_process(response)
@ -133,7 +133,7 @@ class Contract(object):
else:
results.addSuccess(self.testcase_pre)
finally:
return list(iterate_spider_output(cb(response)))
return list(iterate_spider_output(cb(response, **cb_kwargs)))
request.callback = wrapper
@ -144,8 +144,8 @@ class Contract(object):
cb = request.callback
@wraps(cb)
def wrapper(response):
output = list(iterate_spider_output(cb(response)))
def wrapper(response, **cb_kwargs):
output = list(iterate_spider_output(cb(response, **cb_kwargs)))
try:
results.startTest(self.testcase_post)
self.post_process(output)

29
scrapy/contracts/default.py
View File

@ -1,8 +1,10 @@
import json
from scrapy.item import BaseItem
from scrapy.http import Request
from scrapy.exceptions import ContractFail
from . import Contract
from scrapy.contracts import Contract
# contracts
@ -18,6 +20,20 @@ class UrlContract(Contract):
return args
class CallbackKeywordArgumentsContract(Contract):
""" Contract to set the keyword arguments for the request.
The value should be a JSON-encoded dictionary, e.g.:
@cb_kwargs {"arg1": "some value"}
"""
name = 'cb_kwargs'
def adjust_request_args(self, args):
args['cb_kwargs'] = json.loads(' '.join(self.args))
return args
class ReturnsContract(Contract):
""" Contract to check the output of a callback
@ -70,8 +86,8 @@ class ReturnsContract(Contract):
else:
expected = '%s..%s' % (self.min_bound, self.max_bound)
raise ContractFail("Returned %s %s, expected %s" % \
(occurrences, self.obj_name, expected))
raise ContractFail("Returned %s %s, expected %s" %
(occurrences, self.obj_name, expected))
class ScrapesContract(Contract):
@ -84,6 +100,7 @@ class ScrapesContract(Contract):
def post_process(self, output):
for x in output:
if isinstance(x, (BaseItem, dict)):
for arg in self.args:
if not arg in x:
raise ContractFail("'%s' field is missing" % arg)
missing = [arg for arg in self.args if arg not in x]
if missing:
raise ContractFail(
"Missing fields: %s" % ", ".join(missing))

24
scrapy/core/downloader/__init__.py
View File

@ -1,19 +1,16 @@
from __future__ import absolute_import
import random
import warnings
from time import time
from datetime import datetime
from collections import deque
import six
from twisted.internet import reactor, defer, task
from scrapy.utils.defer import mustbe_deferred
from scrapy.utils.httpobj import urlparse_cached
from scrapy.resolver import dnscache
from scrapy import signals
from .middleware import DownloaderMiddlewareManager
from .handlers import DownloadHandlers
from scrapy.core.downloader.middleware import DownloaderMiddlewareManager
from scrapy.core.downloader.handlers import DownloadHandlers
class Slot(object):
@ -60,10 +57,6 @@ class Slot(object):
def _get_concurrency_delay(concurrency, spider, settings):
delay = settings.getfloat('DOWNLOAD_DELAY')
if hasattr(spider, 'DOWNLOAD_DELAY'):
warnings.warn("%s.DOWNLOAD_DELAY attribute is deprecated, use %s.download_delay instead" %
(type(spider).__name__, type(spider).__name__))
delay = spider.DOWNLOAD_DELAY
if hasattr(spider, 'download_delay'):
delay = spider.download_delay
@ -75,6 +68,8 @@ def _get_concurrency_delay(concurrency, spider, settings):
class Downloader(object):
DOWNLOAD_SLOT = 'download_slot'
def __init__(self, crawler):
self.settings = crawler.settings
self.signals = crawler.signals
@ -111,8 +106,8 @@ class Downloader(object):
return key, self.slots[key]
def _get_slot_key(self, request, spider):
if 'download_slot' in request.meta:
return request.meta['download_slot']
if self.DOWNLOAD_SLOT in request.meta:
return request.meta[self.DOWNLOAD_SLOT]
key = urlparse_cached(request).hostname or ''
if self.ip_concurrency:
@ -122,7 +117,7 @@ class Downloader(object):
def _enqueue_request(self, request, spider):
key, slot = self._get_slot(request, spider)
request.meta['download_slot'] = key
request.meta[self.DOWNLOAD_SLOT] = key
def _deactivate(response):
slot.active.remove(request)
@ -186,13 +181,16 @@ class Downloader(object):
def finish_transferring(_):
slot.transferring.remove(request)
self._process_queue(spider, slot)
self.signals.send_catch_log(signal=signals.request_left_downloader,
request=request,
spider=spider)
return _
return dfd.addBoth(finish_transferring)
def close(self):
self._slot_gc_loop.stop()
for slot in six.itervalues(self.slots):
for slot in self.slots.values():
slot.close()
def _slot_gc(self, age=60):

162
scrapy/core/downloader/contextfactory.py
View File

@ -1,105 +1,93 @@
from OpenSSL import SSL
from twisted.internet.ssl import ClientContextFactory
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 scrapy import twisted_version
if twisted_version >= (14, 0, 0):
from zope.interface.declarations import implementer
from twisted.internet.ssl import (optionsForClientTLS,
CertificateOptions,
platformTrust)
from twisted.web.client import BrowserLikePolicyForHTTPS
from twisted.web.iweb import IPolicyForHTTPS
from scrapy.core.downloader.tls import ScrapyClientTLSOptions, DEFAULT_CIPHERS
from scrapy.core.downloader.tls import ScrapyClientTLSOptions, DEFAULT_CIPHERS
@implementer(IPolicyForHTTPS)
class ScrapyClientContextFactory(BrowserLikePolicyForHTTPS):
"""
Non-peer-certificate verifying HTTPS context factory
@implementer(IPolicyForHTTPS)
class ScrapyClientContextFactory(BrowserLikePolicyForHTTPS):
"""
Non-peer-certificate verifying HTTPS context factory
Default OpenSSL method is TLS_METHOD (also called SSLv23_METHOD)
which allows TLS protocol negotiation
Default OpenSSL method is TLS_METHOD (also called SSLv23_METHOD)
which allows TLS protocol negotiation
'A TLS/SSL connection established with [this method] may
understand the SSLv3, TLSv1, TLSv1.1 and TLSv1.2 protocols.'
"""
'A TLS/SSL connection established with [this method] may
understand the SSLv3, TLSv1, TLSv1.1 and TLSv1.2 protocols.'
"""
def __init__(self, method=SSL.SSLv23_METHOD, *args, **kwargs):
super(ScrapyClientContextFactory, self).__init__(*args, **kwargs)
self._ssl_method = method
def __init__(self, method=SSL.SSLv23_METHOD, tls_verbose_logging=False, tls_ciphers=None, *args, **kwargs):
super(ScrapyClientContextFactory, self).__init__(*args, **kwargs)
self._ssl_method = method
self.tls_verbose_logging = tls_verbose_logging
if tls_ciphers:
self.tls_ciphers = AcceptableCiphers.fromOpenSSLCipherString(tls_ciphers)
else:
self.tls_ciphers = DEFAULT_CIPHERS
def getCertificateOptions(self):
# setting verify=True will require you to provide CAs
# to verify against; in other words: it's not that simple
@classmethod
def from_settings(cls, settings, method=SSL.SSLv23_METHOD, *args, **kwargs):
tls_verbose_logging = settings.getbool('DOWNLOADER_CLIENT_TLS_VERBOSE_LOGGING')
tls_ciphers = settings['DOWNLOADER_CLIENT_TLS_CIPHERS']
return cls(method=method, tls_verbose_logging=tls_verbose_logging, tls_ciphers=tls_ciphers, *args, **kwargs)
# backward-compatible SSL/TLS method:
#
# * this will respect `method` attribute in often recommended
# `ScrapyClientContextFactory` subclass
# (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=DEFAULT_CIPHERS)
def getCertificateOptions(self):
# setting verify=True will require you to provide CAs
# to verify against; in other words: it's not that simple
# kept for old-style HTTP/1.0 downloader context twisted calls,
# e.g. connectSSL()
def getContext(self, hostname=None, port=None):
return self.getCertificateOptions().getContext()
# backward-compatible SSL/TLS method:
#
# * this will respect `method` attribute in often recommended
# `ScrapyClientContextFactory` subclass
# (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)
def creatorForNetloc(self, hostname, port):
return ScrapyClientTLSOptions(hostname.decode("ascii"), self.getContext())
# kept for old-style HTTP/1.0 downloader context twisted calls,
# e.g. connectSSL()
def getContext(self, hostname=None, port=None):
return self.getCertificateOptions().getContext()
def creatorForNetloc(self, hostname, port):
return ScrapyClientTLSOptions(hostname.decode("ascii"), self.getContext(),
verbose_logging=self.tls_verbose_logging)
@implementer(IPolicyForHTTPS)
class BrowserLikeContextFactory(ScrapyClientContextFactory):
"""
Twisted-recommended context factory for web clients.
@implementer(IPolicyForHTTPS)
class BrowserLikeContextFactory(ScrapyClientContextFactory):
"""
Twisted-recommended context factory for web clients.
Quoting https://twistedmatrix.com/documents/current/api/twisted.web.client.Agent.html:
"The default is to use a BrowserLikePolicyForHTTPS,
so unless you have special requirements you can leave this as-is."
Quoting the documentation of the :class:`~twisted.web.client.Agent` class:
creatorForNetloc() is the same as BrowserLikePolicyForHTTPS
except this context factory allows setting the TLS/SSL method to use.
The default is to use a
:class:`~twisted.web.client.BrowserLikePolicyForHTTPS`, so unless you
have special requirements you can leave this as-is.
Default OpenSSL method is TLS_METHOD (also called SSLv23_METHOD)
which allows TLS protocol negotiation.
"""
def creatorForNetloc(self, hostname, port):
:meth:`creatorForNetloc` is the same as
:class:`~twisted.web.client.BrowserLikePolicyForHTTPS` except this context
factory allows setting the TLS/SSL method to use.
# 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,
})
The default OpenSSL method is ``TLS_METHOD`` (also called
``SSLv23_METHOD``) which allows TLS protocol negotiation.
"""
def creatorForNetloc(self, hostname, port):
else:
class ScrapyClientContextFactory(ClientContextFactory):
"A SSL context factory which is more permissive against SSL bugs."
# see https://github.com/scrapy/scrapy/issues/82
# and https://github.com/scrapy/scrapy/issues/26
# and https://github.com/scrapy/scrapy/issues/981
def __init__(self, method=SSL.SSLv23_METHOD):
self.method = method
def getContext(self, hostname=None, port=None):
ctx = ClientContextFactory.getContext(self)
# Enable all workarounds to SSL bugs as documented by
# https://www.openssl.org/docs/manmaster/man3/SSL_CTX_set_options.html
ctx.set_options(SSL.OP_ALL)
return ctx
# 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,
})

21
scrapy/core/downloader/handlers/__init__.py
View File

@ -1,19 +1,20 @@
"""Download handlers for different schemes"""
import logging
from twisted.internet import defer
import six
from scrapy.exceptions import NotSupported, NotConfigured
from scrapy.utils.httpobj import urlparse_cached
from scrapy.utils.misc import load_object
from scrapy.utils.python import without_none_values
from scrapy import signals
from scrapy.exceptions import NotConfigured, NotSupported
from scrapy.utils.httpobj import urlparse_cached
from scrapy.utils.misc import create_instance, load_object
from scrapy.utils.python import without_none_values
logger = logging.getLogger(__name__)
class DownloadHandlers(object):
class DownloadHandlers:
def __init__(self, crawler):
self._crawler = crawler
@ -22,7 +23,7 @@ class DownloadHandlers(object):
self._notconfigured = {} # remembers failed handlers
handlers = without_none_values(
crawler.settings.getwithbase('DOWNLOAD_HANDLERS'))
for scheme, clspath in six.iteritems(handlers):
for scheme, clspath in handlers.items():
self._schemes[scheme] = clspath
self._load_handler(scheme, skip_lazy=True)
@ -48,7 +49,11 @@ class DownloadHandlers(object):
dhcls = load_object(path)
if skip_lazy and getattr(dhcls, 'lazy', True):
return None
dh = dhcls(self._crawler.settings)
dh = create_instance(
objcls=dhcls,
settings=self._crawler.settings,
crawler=self._crawler,
)
except NotConfigured as ex:
self._notconfigured[scheme] = str(ex)
return None

9
scrapy/core/downloader/handlers/datauri.py
View File

@ -5,20 +5,17 @@ from scrapy.responsetypes import responsetypes
from scrapy.utils.decorators import defers
class DataURIDownloadHandler(object):
class DataURIDownloadHandler:
lazy = False
def __init__(self, settings):
super(DataURIDownloadHandler, self).__init__()
@defers
def download_request(self, request, spider):
uri = parse_data_uri(request.url)
respcls = responsetypes.from_mimetype(uri.media_type)
resp_kwargs = {}
if (issubclass(respcls, TextResponse) and
uri.media_type.split('/')[0] == 'text'):
if (issubclass(respcls, TextResponse)
and uri.media_type.split('/')[0] == 'text'):
charset = uri.media_type_parameters.get('charset')
resp_kwargs['encoding'] = charset

6
scrapy/core/downloader/handlers/file.py
View File

@ -1,14 +1,12 @@
from w3lib.url import file_uri_to_path
from scrapy.responsetypes import responsetypes
from scrapy.utils.decorators import defers
class FileDownloadHandler(object):
class FileDownloadHandler:
lazy = False
def __init__(self, settings):
pass
@defers
def download_request(self, request, spider):
filepath = file_uri_to_path(request.url)

16
scrapy/core/downloader/handlers/ftp.py
View File

@ -30,11 +30,11 @@ In case of status 200 request, response.headers will come with two keys:
import re
from io import BytesIO
from six.moves.urllib.parse import unquote
from urllib.parse import unquote
from twisted.internet import reactor
from twisted.protocols.ftp import FTPClient, CommandFailed
from twisted.internet.protocol import Protocol, ClientCreator
from twisted.internet.protocol import ClientCreator, Protocol
from twisted.protocols.ftp import CommandFailed, FTPClient
from scrapy.http import Response
from scrapy.responsetypes import responsetypes
@ -59,10 +59,11 @@ class ReceivedDataProtocol(Protocol):
def close(self):
self.body.close() if self.filename else self.body.seek(0)
_CODE_RE = re.compile("\d+")
_CODE_RE = re.compile(r"\d+")
class FTPDownloadHandler(object):
class FTPDownloadHandler:
lazy = False
CODE_MAPPING = {
@ -75,6 +76,10 @@ class FTPDownloadHandler(object):
self.default_password = settings['FTP_PASSWORD']
self.passive_mode = settings['FTP_PASSIVE_MODE']
@classmethod
def from_crawler(cls, crawler):
return cls(crawler.settings)
def download_request(self, request, spider):
parsed_url = urlparse_cached(request)
user = request.meta.get("ftp_user", self.default_user)
@ -112,4 +117,3 @@ class FTPDownloadHandler(object):
httpcode = self.CODE_MAPPING.get(ftpcode, self.CODE_MAPPING["default"])
return Response(url=request.url, status=httpcode, body=to_bytes(message))
raise result.type(result.value)

19
scrapy/core/downloader/handlers/http.py
View File

@ -1,15 +1,4 @@
from __future__ import absolute_import
from .http10 import HTTP10DownloadHandler
from .http11 import HTTP11DownloadHandler as HTTPDownloadHandler
# backward compatibility
class HttpDownloadHandler(HTTP10DownloadHandler):
def __init__(self, *args, **kwargs):
import warnings
from scrapy.exceptions import ScrapyDeprecationWarning
warnings.warn('HttpDownloadHandler is deprecated, import scrapy.core.downloader'
'.handlers.http10.HTTP10DownloadHandler instead',
category=ScrapyDeprecationWarning, stacklevel=1)
super(HttpDownloadHandler, self).__init__(*args, **kwargs)
from scrapy.core.downloader.handlers.http10 import HTTP10DownloadHandler
from scrapy.core.downloader.handlers.http11 import (
HTTP11DownloadHandler as HTTPDownloadHandler,
)

21
scrapy/core/downloader/handlers/http10.py
View File

@ -1,16 +1,23 @@
"""Download handlers for http and https schemes
"""
from twisted.internet import reactor
from scrapy.utils.misc import load_object
from scrapy.utils.misc import create_instance, load_object
from scrapy.utils.python import to_unicode
class HTTP10DownloadHandler(object):
class HTTP10DownloadHandler:
lazy = False
def __init__(self, settings):
def __init__(self, settings, crawler=None):
self.HTTPClientFactory = load_object(settings['DOWNLOADER_HTTPCLIENTFACTORY'])
self.ClientContextFactory = load_object(settings['DOWNLOADER_CLIENTCONTEXTFACTORY'])
self._settings = settings
self._crawler = crawler
@classmethod
def from_crawler(cls, crawler):
return cls(crawler.settings, crawler)
def download_request(self, request, spider):
"""Return a deferred for the HTTP download"""
@ -21,7 +28,11 @@ class HTTP10DownloadHandler(object):
def _connect(self, factory):
host, port = to_unicode(factory.host), factory.port
if factory.scheme == b'https':
return reactor.connectSSL(host, port, factory,
self.ClientContextFactory())
client_context_factory = create_instance(
objcls=self.ClientContextFactory,
settings=self._settings,
crawler=self._crawler,
)
return reactor.connectSSL(host, port, factory, client_context_factory)
else:
return reactor.connectTCP(host, port, factory)

234
scrapy/core/downloader/handlers/http11.py
View File

@ -1,41 +1,37 @@
"""Download handlers for http and https schemes"""
import re
import logging
import re
import warnings
from io import BytesIO
from time import time
import warnings
from six.moves.urllib.parse import urldefrag
from urllib.parse import urldefrag
from zope.interface import implementer
from twisted.internet import defer, reactor, protocol
from twisted.internet import defer, protocol, reactor
from twisted.internet.endpoints import TCP4ClientEndpoint
from twisted.internet.error import TimeoutError
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 twisted.internet.error import TimeoutError
from twisted.web.http import _DataLoss, PotentialDataLoss
from twisted.web.client import Agent, ProxyAgent, ResponseDone, \
HTTPConnectionPool, ResponseFailed
try:
from twisted.web.client import URI
except ImportError:
from twisted.web.client import _URI as URI
from twisted.internet.endpoints import TCP4ClientEndpoint
from zope.interface import implementer
from scrapy.core.downloader.tls import openssl_methods
from scrapy.core.downloader.webclient import _parse
from scrapy.exceptions import ScrapyDeprecationWarning
from scrapy.http import Headers
from scrapy.responsetypes import responsetypes
from scrapy.core.downloader.webclient import _parse
from scrapy.core.downloader.tls import openssl_methods
from scrapy.utils.misc import load_object
from scrapy.utils.misc import create_instance, load_object
from scrapy.utils.python import to_bytes, to_unicode
from scrapy import twisted_version
logger = logging.getLogger(__name__)
class HTTP11DownloadHandler(object):
class HTTP11DownloadHandler:
lazy = False
def __init__(self, settings):
def __init__(self, settings, crawler=None):
self._pool = HTTPConnectionPool(reactor, persistent=True)
self._pool.maxPersistentPerHost = settings.getint('CONCURRENT_REQUESTS_PER_DOMAIN')
self._pool._factory.noisy = False
@ -44,14 +40,23 @@ class HTTP11DownloadHandler(object):
self._contextFactoryClass = load_object(settings['DOWNLOADER_CLIENTCONTEXTFACTORY'])
# try method-aware context factory
try:
self._contextFactory = self._contextFactoryClass(method=self._sslMethod)
self._contextFactory = create_instance(
objcls=self._contextFactoryClass,
settings=settings,
crawler=crawler,
method=self._sslMethod,
)
except TypeError:
# use context factory defaults
self._contextFactory = self._contextFactoryClass()
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).\
Please upgrade your context factory class to handle it or ignore it.""" % (
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._default_maxsize = settings.getint('DOWNLOAD_MAXSIZE')
@ -59,12 +64,19 @@ class HTTP11DownloadHandler(object):
self._fail_on_dataloss = settings.getbool('DOWNLOAD_FAIL_ON_DATALOSS')
self._disconnect_timeout = 1
@classmethod
def from_crawler(cls, crawler):
return cls(crawler.settings, crawler)
def download_request(self, request, spider):
"""Return a deferred for the HTTP download"""
agent = ScrapyAgent(contextFactory=self._contextFactory, pool=self._pool,
agent = ScrapyAgent(
contextFactory=self._contextFactory,
pool=self._pool,
maxsize=getattr(spider, 'download_maxsize', self._default_maxsize),
warnsize=getattr(spider, 'download_warnsize', self._default_warnsize),
fail_on_dataloss=self._fail_on_dataloss)
fail_on_dataloss=self._fail_on_dataloss,
)
return agent.download_request(request)
def close(self):
@ -101,13 +113,11 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
for it.
"""
_responseMatcher = re.compile(b'HTTP/1\.. (?P<status>\d{3})(?P<reason>.{,32})')
_responseMatcher = re.compile(br'HTTP/1\.. (?P<status>\d{3})(?P<reason>.{,32})')
def __init__(self, reactor, host, port, proxyConf, contextFactory,
timeout=30, bindAddress=None):
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(TunnelingTCP4ClientEndpoint, self).__init__(reactor, proxyHost, proxyPort, timeout, bindAddress)
self._tunnelReadyDeferred = defer.Deferred()
self._tunneledHost = host
self._tunneledPort = port
@ -116,8 +126,7 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
def requestTunnel(self, protocol):
"""Asks the proxy to open a tunnel."""
tunnelReq = tunnel_request_data(self._tunneledHost, self._tunneledPort,
self._proxyAuthHeader)
tunnelReq = tunnel_request_data(self._tunneledHost, self._tunneledPort, self._proxyAuthHeader)
protocol.transport.write(tunnelReq)
self._protocolDataReceived = protocol.dataReceived
protocol.dataReceived = self.processProxyResponse
@ -140,16 +149,9 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
self._protocol.dataReceived = self._protocolDataReceived
respm = TunnelingTCP4ClientEndpoint._responseMatcher.match(self._connectBuffer)
if respm and int(respm.group('status')) == 200:
try:
# this sets proper Server Name Indication extension
# but is only available for Twisted>=14.0
sslOptions = self._contextFactory.creatorForNetloc(
self._tunneledHost, self._tunneledPort)
except AttributeError:
# fall back to non-SNI SSL context factory
sslOptions = self._contextFactory
self._protocol.transport.startTLS(sslOptions,
self._protocolFactory)
# set proper Server Name Indication extension
sslOptions = self._contextFactory.creatorForNetloc(self._tunneledHost, self._tunneledPort)
self._protocol.transport.startTLS(sslOptions, self._protocolFactory)
self._tunnelReadyDeferred.callback(self._protocol)
else:
if respm:
@ -167,8 +169,7 @@ class TunnelingTCP4ClientEndpoint(TCP4ClientEndpoint):
def connect(self, protocolFactory):
self._protocolFactory = protocolFactory
connectDeferred = super(TunnelingTCP4ClientEndpoint,
self).connect(protocolFactory)
connectDeferred = super(TunnelingTCP4ClientEndpoint, self).connect(protocolFactory)
connectDeferred.addCallback(self.requestTunnel)
connectDeferred.addErrback(self.connectFailed)
return self._tunnelReadyDeferred
@ -178,7 +179,7 @@ def tunnel_request_data(host, port, proxy_auth_header=None):
r"""
Return binary content of a CONNECT request.
>>> from scrapy.utils.python import to_native_str as s
>>> from scrapy.utils.python import to_unicode as s
>>> s(tunnel_request_data("example.com", 8080))
'CONNECT example.com:8080 HTTP/1.1\r\nHost: example.com:8080\r\n\r\n'
>>> s(tunnel_request_data("example.com", 8080, b"123"))
@ -205,42 +206,46 @@ 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(TunnelingAgent, self).__init__(reactor, contextFactory, connectTimeout, bindAddress, pool)
self._proxyConf = proxyConf
self._contextFactory = contextFactory
if twisted_version >= (15, 0, 0):
def _getEndpoint(self, uri):
return TunnelingTCP4ClientEndpoint(
self._reactor, uri.host, uri.port, self._proxyConf,
self._contextFactory, self._endpointFactory._connectTimeout,
self._endpointFactory._bindAddress)
else:
def _getEndpoint(self, scheme, host, port):
return TunnelingTCP4ClientEndpoint(
self._reactor, host, port, self._proxyConf,
self._contextFactory, self._connectTimeout,
self._bindAddress)
def _getEndpoint(self, uri):
return TunnelingTCP4ClientEndpoint(
reactor=self._reactor,
host=uri.host,
port=uri.port,
proxyConf=self._proxyConf,
contextFactory=self._contextFactory,
timeout=self._endpointFactory._connectTimeout,
bindAddress=self._endpointFactory._bindAddress,
)
def _requestWithEndpoint(self, key, endpoint, method, parsedURI,
headers, bodyProducer, requestPath):
def _requestWithEndpoint(self, key, endpoint, method, parsedURI, headers, bodyProducer, requestPath):
# proxy host and port are required for HTTP pool `key`
# 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(key, endpoint, method, parsedURI,
headers, bodyProducer, requestPath)
return super(TunnelingAgent, self)._requestWithEndpoint(
key=key,
endpoint=endpoint,
method=method,
parsedURI=parsedURI,
headers=headers,
bodyProducer=bodyProducer,
requestPath=requestPath,
)
class ScrapyProxyAgent(Agent):
def __init__(self, reactor, proxyURI,
connectTimeout=None, bindAddress=None, pool=None):
super(ScrapyProxyAgent, self).__init__(reactor,
connectTimeout=connectTimeout,
bindAddress=bindAddress,
pool=pool)
def __init__(self, reactor, proxyURI, connectTimeout=None, bindAddress=None, pool=None):
super(ScrapyProxyAgent, self).__init__(
reactor=reactor,
connectTimeout=connectTimeout,
bindAddress=bindAddress,
pool=pool,
)
self._proxyURI = URI.fromBytes(proxyURI)
def request(self, method, uri, headers=None, bodyProducer=None):
@ -249,16 +254,15 @@ class ScrapyProxyAgent(Agent):
"""
# Cache *all* connections under the same key, since we are only
# connecting to a single destination, the proxy:
if twisted_version >= (15, 0, 0):
proxyEndpoint = self._getEndpoint(self._proxyURI)
else:
proxyEndpoint = self._getEndpoint(self._proxyURI.scheme,
self._proxyURI.host,
self._proxyURI.port)
key = ("http-proxy", self._proxyURI.host, self._proxyURI.port)
return self._requestWithEndpoint(key, proxyEndpoint, method,
URI.fromBytes(uri), headers,
bodyProducer, uri)
return self._requestWithEndpoint(
key=("http-proxy", self._proxyURI.host, self._proxyURI.port),
endpoint=self._getEndpoint(self._proxyURI),
method=method,
parsedURI=URI.fromBytes(uri),
headers=headers,
bodyProducer=bodyProducer,
requestPath=uri,
)
class ScrapyAgent(object):
@ -286,18 +290,39 @@ class ScrapyAgent(object):
scheme = _parse(request.url)[0]
proxyHost = to_unicode(proxyHost)
omitConnectTunnel = b'noconnect' in proxyParams
if scheme == b'https' and not omitConnectTunnel:
proxyConf = (proxyHost, proxyPort,
request.headers.get(b'Proxy-Authorization', None))
return self._TunnelingAgent(reactor, proxyConf,
contextFactory=self._contextFactory, connectTimeout=timeout,
bindAddress=bindaddress, pool=self._pool)
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)
if scheme == b'https' and not omitConnectTunnel:
proxyAuth = request.headers.get(b'Proxy-Authorization', None)
proxyConf = (proxyHost, proxyPort, proxyAuth)
return self._TunnelingAgent(
reactor=reactor,
proxyConf=proxyConf,
contextFactory=self._contextFactory,
connectTimeout=timeout,
bindAddress=bindaddress,
pool=self._pool,
)
else:
return self._ProxyAgent(reactor, proxyURI=to_bytes(proxy, encoding='ascii'),
connectTimeout=timeout, bindAddress=bindaddress, pool=self._pool)
return self._ProxyAgent(
reactor=reactor,
proxyURI=to_bytes(proxy, encoding='ascii'),
connectTimeout=timeout,
bindAddress=bindaddress,
pool=self._pool,
)
return self._Agent(reactor, contextFactory=self._contextFactory,
connectTimeout=timeout, bindAddress=bindaddress, pool=self._pool)
return self._Agent(
reactor=reactor,
contextFactory=self._contextFactory,
connectTimeout=timeout,
bindAddress=bindaddress,
pool=self._pool,
)
def download_request(self, request):
timeout = request.meta.get('download_timeout') or self._connectTimeout
@ -328,8 +353,7 @@ class ScrapyAgent(object):
else:
bodyproducer = None
start_time = time()
d = agent.request(
method, to_bytes(url, encoding='ascii'), headers, bodyproducer)
d = agent.request(method, to_bytes(url, encoding='ascii'), headers, bodyproducer)
# set download latency
d.addCallback(self._cb_latency, request, start_time)
# response body is ready to be consumed
@ -384,8 +408,9 @@ class ScrapyAgent(object):
txresponse._transport._producer.abortConnection()
d = defer.Deferred(_cancel)
txresponse.deliverBody(_ResponseReader(
d, txresponse, request, maxsize, warnsize, fail_on_dataloss))
txresponse.deliverBody(
_ResponseReader(d, txresponse, request, maxsize, warnsize, fail_on_dataloss)
)
# save response for timeouts
self._txresponse = txresponse
@ -420,22 +445,20 @@ class _RequestBodyProducer(object):
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):
self._finished = finished
self._txresponse = txresponse
self._request = request
self._bodybuf = BytesIO()
self._maxsize = maxsize
self._warnsize = warnsize
self._maxsize = maxsize
self._warnsize = warnsize
self._fail_on_dataloss = fail_on_dataloss
self._fail_on_dataloss_warned = False
self._reached_warnsize = False
self._bytes_received = 0
def dataReceived(self, bodyBytes):
# This maybe called several times after cancel was called with buffered
# data.
# This maybe called several times after cancel was called with buffered data.
if self._finished.called:
return
@ -448,8 +471,7 @@ class _ResponseReader(protocol.Protocol):
{'bytes': self._bytes_received,
'maxsize': self._maxsize,
'request': self._request})
# Clear buffer earlier to avoid keeping data in memory for a long
# time.
# Clear buffer earlier to avoid keeping data in memory for a long time.
self._bodybuf.truncate(0)
self._finished.cancel()
@ -479,10 +501,10 @@ class _ResponseReader(protocol.Protocol):
return
elif not self._fail_on_dataloss_warned:
logger.warn("Got data loss in %s. If you want to process broken "
"responses set the setting DOWNLOAD_FAIL_ON_DATALOSS = False"
" -- This message won't be shown in further requests",
self._txresponse.request.absoluteURI.decode())
logger.warning("Got data loss in %s. If you want to process broken "
"responses set the setting DOWNLOAD_FAIL_ON_DATALOSS = False"
" -- This message won't be shown in further requests",
self._txresponse.request.absoluteURI.decode())
self._fail_on_dataloss_warned = True
self._finished.errback(reason)

29
scrapy/core/downloader/handlers/s3.py
View File

@ -1,9 +1,10 @@
from six.moves.urllib.parse import unquote
from urllib.parse import unquote
from scrapy.core.downloader.handlers.http import HTTPDownloadHandler
from scrapy.exceptions import NotConfigured
from scrapy.utils.httpobj import urlparse_cached
from scrapy.utils.boto import is_botocore
from .http import HTTPDownloadHandler
from scrapy.utils.httpobj import urlparse_cached
from scrapy.utils.misc import create_instance
def _get_boto_connection():
@ -21,7 +22,7 @@ def _get_boto_connection():
return http_request.headers
try:
import boto.auth
import boto.auth # noqa: F401
except ImportError:
_S3Connection = _v19_S3Connection
else:
@ -30,11 +31,12 @@ def _get_boto_connection():
return _S3Connection
class S3DownloadHandler(object):
def __init__(self, settings, aws_access_key_id=None, aws_secret_access_key=None, \
httpdownloadhandler=HTTPDownloadHandler, **kw):
class S3DownloadHandler:
def __init__(self, settings, *,
crawler=None,
aws_access_key_id=None, aws_secret_access_key=None,
httpdownloadhandler=HTTPDownloadHandler, **kw):
if not aws_access_key_id:
aws_access_key_id = settings['AWS_ACCESS_KEY_ID']
if not aws_secret_access_key:
@ -67,7 +69,16 @@ class S3DownloadHandler(object):
except Exception as ex:
raise NotConfigured(str(ex))
self._download_http = httpdownloadhandler(settings).download_request
_http_handler = create_instance(
objcls=httpdownloadhandler,
settings=settings,
crawler=crawler,
)
self._download_http = _http_handler.download_request
@classmethod
def from_crawler(cls, crawler, **kwargs):
return cls(crawler.settings, crawler=crawler, **kwargs)
def download_request(self, request, spider):
p = urlparse_cached(request)

33
scrapy/core/downloader/middleware.py
View File

@ -3,13 +3,12 @@ Downloader Middleware manager
See documentation in docs/topics/downloader-middleware.rst
"""
import six
from twisted.internet import defer
from scrapy.exceptions import _InvalidOutput
from scrapy.http import Request, Response
from scrapy.middleware import MiddlewareManager
from scrapy.utils.defer import mustbe_deferred
from scrapy.utils.defer import mustbe_deferred, deferred_from_coro
from scrapy.utils.conf import build_component_list
@ -34,13 +33,13 @@ class DownloaderMiddlewareManager(MiddlewareManager):
@defer.inlineCallbacks
def process_request(request):
for method in self.methods['process_request']:
response = yield method(request=request, spider=spider)
assert response is None or isinstance(response, (Response, Request)), \
'Middleware %s.process_request must return None, Response or Request, got %s' % \
(six.get_method_self(method).__class__.__name__, response.__class__.__name__)
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__))
if response:
defer.returnValue(response)
defer.returnValue((yield download_func(request=request,spider=spider)))
defer.returnValue((yield download_func(request=request, spider=spider)))
@defer.inlineCallbacks
def process_response(response):
@ -49,11 +48,10 @@ class DownloaderMiddlewareManager(MiddlewareManager):
defer.returnValue(response)
for method in self.methods['process_response']:
response = yield method(request=request, response=response,
spider=spider)
assert isinstance(response, (Response, Request)), \
'Middleware %s.process_response must return Response or Request, got %s' % \
(six.get_method_self(method).__class__.__name__, type(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)))
if isinstance(response, Request):
defer.returnValue(response)
defer.returnValue(response)
@ -62,11 +60,10 @@ class DownloaderMiddlewareManager(MiddlewareManager):
def process_exception(_failure):
exception = _failure.value
for method in self.methods['process_exception']:
response = yield method(request=request, exception=exception,
spider=spider)
assert response is None or isinstance(response, (Response, Request)), \
'Middleware %s.process_exception must return None, Response or Request, got %s' % \
(six.get_method_self(method).__class__.__name__, type(response))
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)))
if response:
defer.returnValue(response)
defer.returnValue(_failure)

122
scrapy/core/downloader/tls.py
View File

@ -1,17 +1,24 @@
import logging
from OpenSSL import SSL
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
logger = logging.getLogger(__name__)
METHOD_SSLv3 = 'SSLv3'
METHOD_TLS = 'TLS'
METHOD_TLSv10 = 'TLSv1.0'
METHOD_TLSv11 = 'TLSv1.1'
METHOD_TLSv12 = 'TLSv1.2'
openssl_methods = {
METHOD_TLS: SSL.SSLv23_METHOD, # protocol negotiation (recommended)
METHOD_SSLv3: SSL.SSLv3_METHOD, # SSL 3 (NOT recommended)
@ -20,69 +27,66 @@ openssl_methods = {
METHOD_TLSv12: getattr(SSL, 'TLSv1_2_METHOD', 6), # TLS 1.2 only
}
if twisted_version >= (14, 0, 0):
# ClientTLSOptions requires a recent-enough version of Twisted.
# Not having ScrapyClientTLSOptions should not matter for older
# Twisted versions because it is not used in the fallback
# ScrapyClientContextFactory.
# taken from twisted/twisted/internet/_sslverify.py
try:
# XXX: this try-except is not needed in Twisted 17.0.0+ because
# it requires pyOpenSSL 0.16+.
from OpenSSL.SSL import SSL_CB_HANDSHAKE_DONE, SSL_CB_HANDSHAKE_START
except ImportError:
SSL_CB_HANDSHAKE_START = 0x10
SSL_CB_HANDSHAKE_DONE = 0x20
from twisted.internet.ssl import AcceptableCiphers
from twisted.internet._sslverify import (ClientTLSOptions,
verifyHostname,
VerificationError)
try:
# XXX: this import would fail on Debian jessie with system installed
# service_identity library, due to lack of cryptography.x509 dependency
# See https://github.com/pyca/service_identity/issues/21
from service_identity.exceptions import CertificateError
verification_errors = (CertificateError, VerificationError)
except ImportError:
verification_errors = VerificationError
if twisted_version < (17, 0, 0):
from twisted.internet._sslverify import _maybeSetHostNameIndication
set_tlsext_host_name = _maybeSetHostNameIndication
else:
def set_tlsext_host_name(connection, hostNameBytes):
connection.set_tlsext_host_name(hostNameBytes)
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
(for genuinely invalid certificates or bugs in verification code).
class ScrapyClientTLSOptions(ClientTLSOptions):
"""
SSL Client connection creator ignoring certificate verification errors
(for genuinely invalid certificates or bugs in verification code).
Same as Twisted's private _sslverify.ClientTLSOptions,
except that VerificationError, CertificateError and ValueError
exceptions are caught, so that the connection is not closed, only
logging warnings.
"""
Same as Twisted's private _sslverify.ClientTLSOptions,
except that VerificationError, CertificateError and ValueError
exceptions are caught, so that the connection is not closed, only
logging warnings. Also, HTTPS connection parameters logging is added.
"""
def _identityVerifyingInfoCallback(self, connection, where, ret):
if where & SSL_CB_HANDSHAKE_START:
set_tlsext_host_name(connection, self._hostnameBytes)
elif where & SSL_CB_HANDSHAKE_DONE:
try:
verifyHostname(connection, self._hostnameASCII)
except verification_errors as e:
logger.warning(
'Remote certificate is not valid for hostname "{}"; {}'.format(
self._hostnameASCII, e))
def __init__(self, hostname, ctx, verbose_logging=False):
super(ScrapyClientTLSOptions, self).__init__(hostname, ctx)
self.verbose_logging = verbose_logging
except ValueError as e:
logger.warning(
'Ignoring error while verifying certificate '
'from host "{}" (exception: {})'.format(
self._hostnameASCII, repr(e)))
def _identityVerifyingInfoCallback(self, connection, where, ret):
if where & SSL.SSL_CB_HANDSHAKE_START:
set_tlsext_host_name(connection, 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(),
)
server_cert = connection.get_peer_certificate()
logger.debug('SSL connection certificate: issuer "%s", subject "%s"',
x509name_to_string(server_cert.get_issuer()),
x509name_to_string(server_cert.get_subject()),
)
key_info = get_temp_key_info(connection._ssl)
if key_info:
logger.debug('SSL temp key: %s', key_info)
DEFAULT_CIPHERS = AcceptableCiphers.fromOpenSSLCipherString('DEFAULT')
try:
verifyHostname(connection, self._hostnameASCII)
except (CertificateError, VerificationError) as e:
logger.warning(
'Remote certificate is not valid for hostname "{}"; {}'.format(
self._hostnameASCII, e))
except ValueError as e:
logger.warning(
'Ignoring error while verifying certificate '
'from host "{}" (exception: {})'.format(
self._hostnameASCII, repr(e)))
DEFAULT_CIPHERS = AcceptableCiphers.fromOpenSSLCipherString('DEFAULT')

13
scrapy/core/downloader/webclient.py
View File

@ -1,5 +1,5 @@
from time import time
from six.moves.urllib.parse import urlparse, urlunparse, urldefrag
from urllib.parse import urlparse, urlunparse, urldefrag
from twisted.web.client import HTTPClientFactory
from twisted.web.http import HTTPClient
@ -42,7 +42,7 @@ class ScrapyHTTPPageGetter(HTTPClient):
delimiter = b'\n'
def connectionMade(self):
self.headers = Headers() # bucket for response headers
self.headers = Headers() # bucket for response headers
# Method command
self.sendCommand(self.factory.method, self.factory.path)
@ -88,14 +88,14 @@ class ScrapyHTTPPageGetter(HTTPClient):
if self.factory.url.startswith(b'https'):
self.transport.stopProducing()
self.factory.noPage(\
defer.TimeoutError("Getting %s took longer than %s seconds." % \
(self.factory.url, self.factory.timeout)))
self.factory.noPage(
defer.TimeoutError("Getting %s took longer than %s seconds." %
(self.factory.url, self.factory.timeout)))
class ScrapyHTTPClientFactory(HTTPClientFactory):
"""Scrapy implementation of the HTTPClientFactory overwriting the
serUrl method to make use of our Url object that cache the parse
setUrl method to make use of our Url object that cache the parse
result.
"""
@ -157,4 +157,3 @@ class ScrapyHTTPClientFactory(HTTPClientFactory):
def gotHeaders(self, headers):
self.headers_time = time()
self.response_headers = headers

9
scrapy/core/engine.py
View File

@ -25,7 +25,7 @@ class Slot(object):
def __init__(self, start_requests, close_if_idle, nextcall, scheduler):
self.closing = False
self.inprogress = set() # requests in progress
self.inprogress = set() # requests in progress
self.start_requests = iter(start_requests)
self.close_if_idle = close_if_idle
self.nextcall = nextcall
@ -233,10 +233,11 @@ class ExecutionEngine(object):
def _on_success(response):
assert isinstance(response, (Response, Request))
if isinstance(response, Response):
response.request = request # tie request to response received
response.request = request # tie request to response received
logkws = self.logformatter.crawled(request, response, spider)
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
self.signals.send_catch_log(signal=signals.response_received, \
if logkws is not None:
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
self.signals.send_catch_log(signal=signals.response_received,
response=response, request=request, spider=spider)
return response

97
scrapy/core/scheduler.py
View File

@ -1,19 +1,46 @@
import os
import json
import logging
import warnings
from os.path import join, exists
from scrapy.utils.reqser import request_to_dict, request_from_dict
from queuelib import PriorityQueue
from scrapy.utils.misc import load_object, create_instance
from scrapy.utils.job import job_dir
from scrapy.utils.deprecate import ScrapyDeprecationWarning
logger = logging.getLogger(__name__)
class Scheduler(object):
"""
Scrapy Scheduler. It allows to enqueue requests and then get
a next request to download. Scheduler is also handling duplication
filtering, via dupefilter.
Prioritization and queueing is not performed by the Scheduler.
User sets ``priority`` field for each Request, and a PriorityQueue
(defined by :setting:`SCHEDULER_PRIORITY_QUEUE`) uses these priorities
to dequeue requests in a desired order.
Scheduler uses two PriorityQueue instances, configured to work in-memory
and on-disk (optional). When on-disk queue is present, it is used by
default, and an in-memory queue is used as a fallback for cases where
a disk queue can't handle a request (can't serialize it).
:setting:`SCHEDULER_MEMORY_QUEUE` and
:setting:`SCHEDULER_DISK_QUEUE` allow to specify lower-level queue classes
which PriorityQueue instances would be instantiated with, to keep requests
on disk and in memory respectively.
Overall, Scheduler is an object which holds several PriorityQueue instances
(in-memory and on-disk) and implements fallback logic for them.
Also, it handles dupefilters.
"""
def __init__(self, dupefilter, jobdir=None, dqclass=None, mqclass=None,
logunser=False, stats=None, pqclass=None):
logunser=False, stats=None, pqclass=None, crawler=None):
self.df = dupefilter
self.dqdir = self._dqdir(jobdir)
self.pqclass = pqclass
@ -21,6 +48,7 @@ class Scheduler(object):
self.mqclass = mqclass
self.logunser = logunser
self.stats = stats
self.crawler = crawler
@classmethod
def from_crawler(cls, crawler):
@ -28,26 +56,35 @@ class Scheduler(object):
dupefilter_cls = load_object(settings['DUPEFILTER_CLASS'])
dupefilter = create_instance(dupefilter_cls, settings, crawler)
pqclass = load_object(settings['SCHEDULER_PRIORITY_QUEUE'])
if pqclass is PriorityQueue:
warnings.warn("SCHEDULER_PRIORITY_QUEUE='queuelib.PriorityQueue'"
" is no longer supported because of API changes; "
"please use 'scrapy.pqueues.ScrapyPriorityQueue'",
ScrapyDeprecationWarning)
from scrapy.pqueues import ScrapyPriorityQueue
pqclass = ScrapyPriorityQueue
dqclass = load_object(settings['SCHEDULER_DISK_QUEUE'])
mqclass = load_object(settings['SCHEDULER_MEMORY_QUEUE'])
logunser = settings.getbool('LOG_UNSERIALIZABLE_REQUESTS', settings.getbool('SCHEDULER_DEBUG'))
logunser = settings.getbool('LOG_UNSERIALIZABLE_REQUESTS',
settings.getbool('SCHEDULER_DEBUG'))
return cls(dupefilter, jobdir=job_dir(settings), logunser=logunser,
stats=crawler.stats, pqclass=pqclass, dqclass=dqclass, mqclass=mqclass)
stats=crawler.stats, pqclass=pqclass, dqclass=dqclass,
mqclass=mqclass, crawler=crawler)
def has_pending_requests(self):
return len(self) > 0
def open(self, spider):
self.spider = spider
self.mqs = self.pqclass(self._newmq)
self.mqs = self._mq()
self.dqs = self._dq() if self.dqdir else None
return self.df.open()
def close(self, reason):
if self.dqs:
prios = self.dqs.close()
with open(join(self.dqdir, 'active.json'), 'w') as f:
json.dump(prios, f)
state = self.dqs.close()
self._write_dqs_state(self.dqdir, state)
return self.df.close(reason)
def enqueue_request(self, request):
@ -82,8 +119,7 @@ class Scheduler(object):
if self.dqs is None:
return
try:
reqd = request_to_dict(request, self.spider)
self.dqs.push(reqd, -request.priority)
self.dqs.push(request, -request.priority)
except ValueError as e: # non serializable request
if self.logunser:
msg = ("Unable to serialize request: %(request)s - reason:"
@ -103,32 +139,51 @@ class Scheduler(object):
def _dqpop(self):
if self.dqs:
d = self.dqs.pop()
if d:
return request_from_dict(d, self.spider)
return self.dqs.pop()
def _newmq(self, priority):
""" Factory for creating memory queues. """
return self.mqclass()
def _newdq(self, priority):
return self.dqclass(join(self.dqdir, 'p%s' % priority))
""" Factory for creating disk queues. """
path = join(self.dqdir, 'p%s' % (priority, ))
return self.dqclass(path)
def _mq(self):
""" Create a new priority queue instance, with in-memory storage """
return create_instance(self.pqclass, None, self.crawler, self._newmq,
serialize=False)
def _dq(self):
activef = join(self.dqdir, 'active.json')
if exists(activef):
with open(activef) as f:
prios = json.load(f)
else:
prios = ()
q = self.pqclass(self._newdq, startprios=prios)
""" Create a new priority queue instance, with disk storage """
state = self._read_dqs_state(self.dqdir)
q = create_instance(self.pqclass,
None,
self.crawler,
self._newdq,
state,
serialize=True)
if q:
logger.info("Resuming crawl (%(queuesize)d requests scheduled)",
{'queuesize': len(q)}, extra={'spider': self.spider})
return q
def _dqdir(self, jobdir):
""" Return a folder name to keep disk queue state at """
if jobdir:
dqdir = join(jobdir, 'requests.queue')
if not exists(dqdir):
os.makedirs(dqdir)
return dqdir
def _read_dqs_state(self, dqdir):
path = join(dqdir, 'active.json')
if not exists(path):
return ()
with open(path) as f:
return json.load(f)
def _write_dqs_state(self, dqdir, state):
with open(join(dqdir, 'active.json'), 'w') as f:
json.dump(state, f)

37
scrapy/core/scraper.py
View File

@ -9,7 +9,7 @@ from twisted.internet import defer
from scrapy.utils.defer import defer_result, defer_succeed, parallel, iter_errback
from scrapy.utils.spider import iterate_spider_output
from scrapy.utils.misc import load_object
from scrapy.utils.misc import load_object, warn_on_generator_with_return_value
from scrapy.utils.log import logformatter_adapter, failure_to_exc_info
from scrapy.exceptions import CloseSpider, DropItem, IgnoreRequest
from scrapy import signals
@ -18,6 +18,7 @@ from scrapy.item import BaseItem
from scrapy.core.spidermw import SpiderMiddlewareManager
from scrapy.utils.request import referer_str
logger = logging.getLogger(__name__)
@ -77,7 +78,7 @@ class Scraper(object):
@defer.inlineCallbacks
def open_spider(self, spider):
"""Open the given spider for scraping and allocate resources for it"""
self.slot = Slot()
self.slot = Slot(self.crawler.settings.getint('SCRAPER_SLOT_MAX_ACTIVE_SIZE'))
yield self.itemproc.open_spider(spider)
def close_spider(self, spider):
@ -99,11 +100,13 @@ class Scraper(object):
def enqueue_scrape(self, response, request, spider):
slot = self.slot
dfd = slot.add_response_request(response, request)
def finish_scraping(_):
slot.finish_response(response, request)
self._check_if_closing(spider, slot)
self._scrape_next(spider, slot)
return _
dfd.addBoth(finish_scraping)
dfd.addErrback(
lambda f: logger.error('Scraper bug processing %(request)s',
@ -123,7 +126,7 @@ class Scraper(object):
callback/errback"""
assert isinstance(response, (Response, Failure))
dfd = self._scrape2(response, request, spider) # returns spiders processed output
dfd = self._scrape2(response, request, spider) # returns spider's processed output
dfd.addErrback(self.handle_spider_error, request, response, spider)
dfd.addCallback(self.handle_spider_output, request, response, spider)
return dfd
@ -135,7 +138,6 @@ class Scraper(object):
return self.spidermw.scrape_response(
self.call_spider, request_result, request, spider)
else:
# FIXME: don't ignore errors in spider middleware
dfd = self.call_spider(request_result, request, spider)
return dfd.addErrback(
self._log_download_errors, request_result, request, spider)
@ -143,7 +145,12 @@ class Scraper(object):
def call_spider(self, result, request, spider):
result.request = request
dfd = defer_result(result)
dfd.addCallbacks(request.callback or spider.parse, request.errback)
callback = request.callback or spider.parse
warn_on_generator_with_return_value(spider, callback)
warn_on_generator_with_return_value(spider, request.errback)
dfd.addCallbacks(callback=callback,
errback=request.errback,
callbackKeywords=request.cb_kwargs)
return dfd.addCallback(iterate_spider_output)
def handle_spider_error(self, _failure, request, response, spider):
@ -171,8 +178,8 @@ class Scraper(object):
if not result:
return defer_succeed(None)
it = iter_errback(result, self.handle_spider_error, request, response, spider)
dfd = parallel(it, self.concurrent_items,
self._process_spidermw_output, request, response, spider)
dfd = parallel(it, self.concurrent_items, self._process_spidermw_output,
request, response, spider)
return dfd
def _process_spidermw_output(self, output, request, response, spider):
@ -199,8 +206,7 @@ class Scraper(object):
"""Log and silence errors that come from the engine (typically download
errors that got propagated thru here)
"""
if (isinstance(download_failure, Failure) and
not download_failure.check(IgnoreRequest)):
if isinstance(download_failure, Failure) and not download_failure.check(IgnoreRequest):
if download_failure.frames:
logger.error('Error downloading %(request)s',
{'request': request},
@ -224,21 +230,22 @@ class Scraper(object):
ex = output.value
if isinstance(ex, DropItem):
logkws = self.logformatter.dropped(item, ex, response, spider)
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
if logkws is not None:
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
return self.signals.send_catch_log_deferred(
signal=signals.item_dropped, item=item, response=response,
spider=spider, exception=output.value)
else:
logger.error('Error processing %(item)s', {'item': item},
exc_info=failure_to_exc_info(output),
extra={'spider': spider})
logkws = self.logformatter.error(item, ex, response, spider)
logger.log(*logformatter_adapter(logkws), extra={'spider': spider},
exc_info=failure_to_exc_info(output))
return self.signals.send_catch_log_deferred(
signal=signals.item_error, item=item, response=response,
spider=spider, failure=output)
else:
logkws = self.logformatter.scraped(output, response, spider)
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
if logkws is not None:
logger.log(*logformatter_adapter(logkws), extra={'spider': spider})
return self.signals.send_catch_log_deferred(
signal=signals.item_scraped, item=output, response=response,
spider=spider)

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