diff --git a/.bumpversion.cfg b/.bumpversion.cfg index c9f1abea5..8d4d74bc5 100644 --- a/.bumpversion.cfg +++ b/.bumpversion.cfg @@ -1,8 +1,7 @@ [bumpversion] -current_version = 1.8.0 +current_version = 2.2.0 commit = True tag = True tag_name = {new_version} [bumpversion:file:scrapy/VERSION] - diff --git a/.gitignore b/.gitignore index ff6e2ea65..83a2569dd 100644 --- a/.gitignore +++ b/.gitignore @@ -15,6 +15,7 @@ htmlcov/ .pytest_cache/ .coverage.* .cache/ +.mypy_cache/ # Windows Thumbs.db diff --git a/.readthedocs.yml b/.readthedocs.yml index 563add75f..e4d3f02cc 100644 --- a/.readthedocs.yml +++ b/.readthedocs.yml @@ -1,9 +1,12 @@ version: 2 +formats: all sphinx: configuration: docs/conf.py + fail_on_warning: true 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 + - path: . diff --git a/.travis.yml b/.travis.yml index 66e1a9617..b403ac54c 100644 --- a/.travis.yml +++ b/.travis.yml @@ -11,25 +11,35 @@ matrix: 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 + - env: TOXENV=pylint python: 3.8 - env: TOXENV=docs python: 3.7 # Keep in sync with .readthedocs.yml + - env: TOXENV=typing + python: 3.8 + + - env: TOXENV=pypy3 + - env: TOXENV=pinned + python: 3.5.2 + - env: TOXENV=asyncio + python: 3.5.2 # We use additional code to support 3.5.3 and earlier + - env: TOXENV=py + python: 3.5 + - env: TOXENV=asyncio + python: 3.5 # We use specific code to support >= 3.5.4, < 3.6 + - env: TOXENV=py + python: 3.6 + - env: TOXENV=py + python: 3.7 + - env: TOXENV=py PYPI_RELEASE_JOB=true + python: 3.8 + dist: bionic + - env: TOXENV=extra-deps + python: 3.8 + dist: bionic + - env: TOXENV=asyncio + python: 3.8 + dist: bionic install: - | if [ "$TOXENV" = "pypy3" ]; then @@ -62,4 +72,4 @@ deploy: on: tags: true repo: scrapy/scrapy - condition: "$TOXENV == py37 && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$" + condition: "$PYPI_RELEASE_JOB == true && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$" diff --git a/Makefile.buildbot b/Makefile.buildbot deleted file mode 100644 index 775538259..000000000 --- a/Makefile.buildbot +++ /dev/null @@ -1,24 +0,0 @@ -TRIAL := $(shell which trial) -BRANCH := $(shell git rev-parse --abbrev-ref HEAD) -export PYTHONPATH=$(PWD) - -test: - coverage run --branch $(TRIAL) --reporter=text tests - rm -rf htmlcov && coverage html - -s3cmd sync -P htmlcov/ s3://static.scrapy.org/coverage-scrapy-$(BRANCH)/ - -build: - git describe --tags --match '[0-9]*' |sed 's/-/.post/;s/-g/+g/' >scrapy/VERSION - debchange -m -D unstable --force-distribution -v \ - $$(python setup.py --version |sed -r 's/([0-9]+.[0-9]+.[0-9]+)(a|b|rc|dev)([0-9]*)/\1~\2\3/')-$$(date +%s) \ - "Automatic build" - debuild -us -uc -b - -clean: - git checkout debian scrapy/VERSION - git clean -dfq - -pypi: - umask 0022 && chmod -R a+rX . && python setup.py sdist upload - -.PHONY: clean test build diff --git a/README.rst b/README.rst index 7fefaeec9..0e3939e9b 100644 --- a/README.rst +++ b/README.rst @@ -40,8 +40,8 @@ including a list of features. Requirements ============ -* Python 3.5+ -* Works on Linux, Windows, Mac OSX, BSD +* Python 3.5.2+ +* Works on Linux, Windows, macOS, BSD Install ======= diff --git a/artwork/README.rst b/artwork/README.rst index 92f6ecb7e..8a1028cde 100644 --- a/artwork/README.rst +++ b/artwork/README.rst @@ -1,5 +1,4 @@ -:orphan: - +============== Scrapy artwork ============== diff --git a/conftest.py b/conftest.py index c0de09909..b39d644a5 100644 --- a/conftest.py +++ b/conftest.py @@ -11,7 +11,11 @@ collect_ignore = [ # 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") + *_py_files("tests/CrawlerProcess"), + # contains scripts to be run by tests/test_crawler.py::CrawlerRunnerSubprocess + *_py_files("tests/CrawlerRunner"), + # Py36-only parts of respective tests + *_py_files("tests/py36"), ] for line in open('tests/ignores.txt'): diff --git a/debian/changelog b/debian/changelog deleted file mode 100644 index dde97f9e3..000000000 --- a/debian/changelog +++ /dev/null @@ -1,5 +0,0 @@ -scrapy (0.11) unstable; urgency=low - - * Initial release. - - -- Scrapinghub Team Thu, 10 Jun 2010 17:24:02 -0300 diff --git a/debian/compat b/debian/compat deleted file mode 100644 index 7f8f011eb..000000000 --- a/debian/compat +++ /dev/null @@ -1 +0,0 @@ -7 diff --git a/debian/control b/debian/control deleted file mode 100644 index 2cc8eedf4..000000000 --- a/debian/control +++ /dev/null @@ -1,20 +0,0 @@ -Source: scrapy -Section: python -Priority: optional -Maintainer: Scrapinghub Team -Build-Depends: debhelper (>= 7.0.50), python (>=2.7), python-twisted, python-w3lib, python-lxml, python-six (>=1.5.2) -Standards-Version: 3.8.4 -Homepage: https://scrapy.org/ - -Package: scrapy -Architecture: all -Depends: ${python:Depends}, python-lxml, python-twisted, python-openssl, - python-w3lib (>= 1.8.0), python-queuelib, python-cssselect (>= 0.9), python-six (>=1.5.2) -Recommends: python-setuptools -Conflicts: python-scrapy, scrapy-0.25 -Provides: python-scrapy, scrapy-0.25 -Description: Python web crawling and web scraping framework - 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. diff --git a/debian/copyright b/debian/copyright deleted file mode 100644 index c1bf47565..000000000 --- a/debian/copyright +++ /dev/null @@ -1,40 +0,0 @@ -This package was debianized by the Scrapinghub team . - -It was downloaded from https://scrapy.org - -Upstream Author: Scrapy Developers - -Copyright: 2007-2013 Scrapy Developers - -License: bsd - -Copyright (c) Scrapy developers. -All rights reserved. - -Redistribution and use in source and binary forms, with or without modification, -are permitted provided that the following conditions are met: - - 1. Redistributions of source code must retain the above copyright notice, - this list of conditions and the following disclaimer. - - 2. Redistributions in binary form must reproduce the above copyright - notice, this list of conditions and the following disclaimer in the - documentation and/or other materials provided with the distribution. - - 3. Neither the name of Scrapy nor the names of its contributors may be used - to endorse or promote products derived from this software without - specific prior written permission. - -THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND -ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED -WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE -DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR -ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES -(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON -ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS -SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -The Debian packaging is (C) 2010-2013, Scrapinghub and -is licensed under the BSD, see `/usr/share/common-licenses/BSD'. diff --git a/debian/pyversions b/debian/pyversions deleted file mode 100644 index 1effb0034..000000000 --- a/debian/pyversions +++ /dev/null @@ -1 +0,0 @@ -2.7 diff --git a/debian/rules b/debian/rules deleted file mode 100755 index b8796e6e3..000000000 --- a/debian/rules +++ /dev/null @@ -1,5 +0,0 @@ -#!/usr/bin/make -f -# -*- makefile -*- - -%: - dh $@ diff --git a/debian/scrapy.docs b/debian/scrapy.docs deleted file mode 100644 index c19ffba4d..000000000 --- a/debian/scrapy.docs +++ /dev/null @@ -1,2 +0,0 @@ -README.rst -AUTHORS diff --git a/debian/scrapy.install b/debian/scrapy.install deleted file mode 100644 index c288ebed3..000000000 --- a/debian/scrapy.install +++ /dev/null @@ -1,2 +0,0 @@ -extras/scrapy_bash_completion etc/bash_completion.d/ -extras/scrapy_zsh_completion /usr/share/zsh/vendor-completions/_scrapy diff --git a/debian/scrapy.lintian-overrides b/debian/scrapy.lintian-overrides deleted file mode 100644 index b5de7f67d..000000000 --- a/debian/scrapy.lintian-overrides +++ /dev/null @@ -1 +0,0 @@ -new-package-should-close-itp-bug diff --git a/debian/scrapy.manpages b/debian/scrapy.manpages deleted file mode 100644 index 4818e9c92..000000000 --- a/debian/scrapy.manpages +++ /dev/null @@ -1 +0,0 @@ -extras/scrapy.1 diff --git a/docs/README.rst b/docs/README.rst index 0a343cd19..0b7afa548 100644 --- a/docs/README.rst +++ b/docs/README.rst @@ -57,3 +57,12 @@ There is a way to recreate the doc automatically when you make changes, you need to install watchdog (``pip install watchdog``) and then use:: make watch + +Alternative method using tox +---------------------------- + +To compile the documentation to HTML run the following command:: + + tox -e docs + +Documentation will be generated (in HTML format) inside the ``.tox/docs/tmp/html`` dir. diff --git a/docs/conf.py b/docs/conf.py index 458bc6087..86734fae7 100644 --- a/docs/conf.py +++ b/docs/conf.py @@ -1,5 +1,3 @@ -# -*- coding: utf-8 -*- -# # Scrapy documentation build configuration file, created by # sphinx-quickstart on Mon Nov 24 12:02:52 2008. # @@ -102,6 +100,9 @@ exclude_trees = ['.build'] # The name of the Pygments (syntax highlighting) style to use. pygments_style = 'sphinx' +# List of Sphinx warnings that will not be raised +suppress_warnings = ['epub.unknown_project_files'] + # Options for HTML output # ----------------------- @@ -280,12 +281,15 @@ coverage_ignore_pyobjects = [ # ------------------------------------- intersphinx_mapping = { + 'attrs': ('https://www.attrs.org/en/stable/', None), 'coverage': ('https://coverage.readthedocs.io/en/stable', None), + 'cssselect': ('https://cssselect.readthedocs.io/en/latest', None), 'pytest': ('https://docs.pytest.org/en/latest', None), 'python': ('https://docs.python.org/3', None), 'sphinx': ('https://www.sphinx-doc.org/en/master', None), 'tox': ('https://tox.readthedocs.io/en/latest', None), 'twisted': ('https://twistedmatrix.com/documents/current', None), + 'twistedapi': ('https://twistedmatrix.com/documents/current/api', None), } @@ -293,3 +297,11 @@ intersphinx_mapping = { # ------------------------------------ hoverxref_auto_ref = True +hoverxref_role_types = { + "class": "tooltip", + "confval": "tooltip", + "hoverxref": "tooltip", + "mod": "tooltip", + "ref": "tooltip", +} +hoverxref_roles = ['command', 'reqmeta', 'setting', 'signal'] diff --git a/docs/contributing.rst b/docs/contributing.rst index f40a6bba2..7b901dd00 100644 --- a/docs/contributing.rst +++ b/docs/contributing.rst @@ -143,7 +143,7 @@ by running ``git fetch upstream pull/$PR_NUMBER/head:$BRANCH_NAME_TO_CREATE`` (replace 'upstream' with a remote name for scrapy repository, ``$PR_NUMBER`` with an ID of the pull request, and ``$BRANCH_NAME_TO_CREATE`` with a name of the branch you want to create locally). -See also: https://help.github.com/articles/checking-out-pull-requests-locally/#modifying-an-inactive-pull-request-locally. +See also: https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/checking-out-pull-requests-locally#modifying-an-inactive-pull-request-locally. When writing GitHub pull requests, try to keep titles short but descriptive. E.g. For bug #411: "Scrapy hangs if an exception raises in start_requests" @@ -155,6 +155,9 @@ Finally, try to keep aesthetic changes (:pep:`8` compliance, unused imports removal, etc) in separate commits from functional changes. This will make pull requests easier to review and more likely to get merged. + +.. _coding-style: + Coding style ============ @@ -163,12 +166,12 @@ Scrapy: * Unless otherwise specified, follow :pep:`8`. -* It's OK to use lines longer than 80 chars if it improves the code +* It's OK to use lines longer than 79 chars if it improves the code readability. * Don't put your name in the code you contribute; git provides enough metadata to identify author of the code. - See https://help.github.com/articles/setting-your-username-in-git/ for + See https://help.github.com/en/github/using-git/setting-your-username-in-git for setup instructions. .. _documentation-policies: @@ -266,5 +269,5 @@ And their unit-tests are in:: .. _tests/: https://github.com/scrapy/scrapy/tree/master/tests .. _open issues: https://github.com/scrapy/scrapy/issues .. _PEP 257: https://www.python.org/dev/peps/pep-0257/ -.. _pull request: https://help.github.com/en/articles/creating-a-pull-request +.. _pull request: https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/creating-a-pull-request .. _pytest-xdist: https://github.com/pytest-dev/pytest-xdist diff --git a/docs/faq.rst b/docs/faq.rst index b65908012..d5ea3cb87 100644 --- a/docs/faq.rst +++ b/docs/faq.rst @@ -22,8 +22,8 @@ In other words, comparing `BeautifulSoup`_ (or `lxml`_) to Scrapy is like comparing `jinja2`_ to `Django`_. .. _BeautifulSoup: https://www.crummy.com/software/BeautifulSoup/ -.. _lxml: http://lxml.de/ -.. _jinja2: http://jinja.pocoo.org/ +.. _lxml: https://lxml.de/ +.. _jinja2: https://palletsprojects.com/p/jinja/ .. _Django: https://www.djangoproject.com/ Can I use Scrapy with BeautifulSoup? @@ -69,7 +69,7 @@ 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 3.5+ +Scrapy is supported under Python 3.5.2+ under CPython (default Python implementation) and PyPy (starting with PyPy 5.9). Python 3 support was added in Scrapy 1.1. PyPy support was added in Scrapy 1.4, PyPy3 support was added in Scrapy 1.5. @@ -269,7 +269,7 @@ The ``__VIEWSTATE`` parameter is used in sites built with ASP.NET/VB.NET. For more info on how it works see `this page`_. Also, here's an `example spider`_ which scrapes one of these sites. -.. _this page: http://search.cpan.org/~ecarroll/HTML-TreeBuilderX-ASP_NET-0.09/lib/HTML/TreeBuilderX/ASP_NET.pm +.. _this page: https://metacpan.org/pod/release/ECARROLL/HTML-TreeBuilderX-ASP_NET-0.09/lib/HTML/TreeBuilderX/ASP_NET.pm .. _example spider: https://github.com/AmbientLighter/rpn-fas/blob/master/fas/spiders/rnp.py What's the best way to parse big XML/CSV data feeds? @@ -342,15 +342,15 @@ method for this purpose. For example:: from copy import deepcopy - from scrapy.item import BaseItem - + from itemadapter import is_item, ItemAdapter class MultiplyItemsMiddleware: def process_spider_output(self, response, result, spider): for item in result: - if isinstance(item, (BaseItem, dict)): - for _ in range(item['multiply_by']): + if is_item(item): + adapter = ItemAdapter(item) + for _ in range(adapter['multiply_by']): yield deepcopy(item) Does Scrapy support IPv6 addresses? @@ -361,6 +361,30 @@ Note that by doing so, you lose the ability to set a specific timeout for DNS re (the value of the :setting:`DNS_TIMEOUT` setting is ignored). +.. _faq-specific-reactor: + +How to deal with ``: 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. + + +.. _faq-stop-response-download: + +How can I cancel the download of a given response? +-------------------------------------------------- + +In some situations, it might be useful to stop the download of a certain response. +For instance, if you only need the first part of a large response and you would like +to save resources by avoiding the download of the whole body. +In that case, you could attach a handler to the :class:`~scrapy.signals.bytes_received` +signal and raise a :exc:`~scrapy.exceptions.StopDownload` exception. Please refer to +the :ref:`topics-stop-response-download` topic for additional information and examples. + + +.. _has been reported: https://github.com/scrapy/scrapy/issues/2905 .. _user agents: https://en.wikipedia.org/wiki/User_agent .. _LIFO: https://en.wikipedia.org/wiki/Stack_(abstract_data_type) .. _DFO order: https://en.wikipedia.org/wiki/Depth-first_search diff --git a/docs/index.rst b/docs/index.rst index a4343b7e0..11aa5c9be 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -165,6 +165,8 @@ Solving specific problems topics/autothrottle topics/benchmarking topics/jobs + topics/coroutines + topics/asyncio :doc:`faq` Get answers to most frequently asked questions. @@ -205,6 +207,12 @@ Solving specific problems :doc:`topics/jobs` Learn how to pause and resume crawls for large spiders. +:doc:`topics/coroutines` + Use the :ref:`coroutine syntax `. + +:doc:`topics/asyncio` + Use :mod:`asyncio` and :mod:`asyncio`-powered libraries. + .. _extending-scrapy: Extending Scrapy diff --git a/docs/intro/install.rst b/docs/intro/install.rst index 178be723c..fb64d443c 100644 --- a/docs/intro/install.rst +++ b/docs/intro/install.rst @@ -7,12 +7,12 @@ Installation guide Installing Scrapy ================= -Scrapy runs on Python 3.5 or above -under CPython (default Python implementation) and PyPy (starting with PyPy 5.9). +Scrapy runs on Python 3.5.2 or above under CPython (default Python +implementation) and PyPy (starting with PyPy 5.9). If you're using `Anaconda`_ or `Miniconda`_, you can install the package from the `conda-forge`_ channel, which has up-to-date packages for Linux, Windows -and OS X. +and macOS. To install Scrapy using ``conda``, run:: @@ -65,7 +65,7 @@ please refer to their respective installation instructions: * `lxml installation`_ * `cryptography installation`_ -.. _lxml installation: http://lxml.de/installation.html +.. _lxml installation: https://lxml.de/installation.html .. _cryptography installation: https://cryptography.io/en/latest/installation/ @@ -81,35 +81,18 @@ Python packages can be installed either globally (a.k.a 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 -"virtual environment" (`virtualenv`_). -Virtualenvs allow you to not conflict with already-installed Python +"virtual environment" (:mod:`venv`). +Virtual environments allow you to not conflict with already-installed Python system packages (which could break some of your system tools and scripts), and still install packages normally with ``pip`` (without ``sudo`` and the likes). -To get started with virtual environments, see `virtualenv installation instructions`_. -To install it globally (having it globally installed actually helps here), -it should be a matter of running:: +See :ref:`tut-venv` on how to create your virtual environment. - $ [sudo] pip install virtualenv - -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 virtual environment, you can install Scrapy inside it with ``pip``, just like any other Python package. (See :ref:`platform-specific guides ` 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. 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/ -.. _virtualenvwrapper: https://virtualenvwrapper.readthedocs.io/en/latest/install.html -.. _user guide: https://virtualenv.pypa.io/en/stable/userguide/ - .. _intro-install-platform-notes: @@ -165,11 +148,11 @@ you can install Scrapy with ``pip`` after that:: .. _intro-install-macos: -Mac OS X --------- +macOS +----- Building Scrapy's dependencies requires the presence of a C compiler and -development headers. On OS X this is typically provided by Apple’s Xcode +development headers. On macOS this is typically provided by Apple’s Xcode development tools. To install the Xcode command line tools open a terminal window and run:: @@ -205,15 +188,12 @@ solutions: brew update; brew upgrade python -* *(Optional)* Install Scrapy inside an isolated python environment. +* *(Optional)* :ref:`Install Scrapy inside a Python virtual environment + `. - This method is a workaround for the above OS X issue, but it's an overall + This method is a workaround for the above macOS issue, but it's an overall good practice for managing dependencies and can complement the first method. - `virtualenv`_ is a tool you can use to create virtual environments in python. - We recommended reading a tutorial like - http://docs.python-guide.org/en/latest/dev/virtualenvs/ to get started. - After any of these workarounds you should be able to install Scrapy:: pip install Scrapy @@ -227,7 +207,7 @@ For PyPy3, only Linux installation was tested. Most Scrapy dependencides now have binary wheels for CPython, but not for PyPy. This means that these dependecies will be built during installation. -On OS X, you are likely to face an issue with building Cryptography dependency, +On macOS, you are likely to face an issue with building Cryptography dependency, solution to this problem is described `here `_, that is to ``brew install openssl`` and then export the flags that this command @@ -273,11 +253,11 @@ For details, see `Issue #2473 `_. .. _Python: https://www.python.org/ .. _pip: https://pip.pypa.io/en/latest/installing/ .. _lxml: https://lxml.de/index.html -.. _parsel: https://pypi.python.org/pypi/parsel -.. _w3lib: https://pypi.python.org/pypi/w3lib -.. _twisted: https://twistedmatrix.com/ -.. _cryptography: https://cryptography.io/ -.. _pyOpenSSL: https://pypi.python.org/pypi/pyOpenSSL +.. _parsel: https://pypi.org/project/parsel/ +.. _w3lib: https://pypi.org/project/w3lib/ +.. _twisted: https://twistedmatrix.com/trac/ +.. _cryptography: https://cryptography.io/en/latest/ +.. _pyOpenSSL: https://pypi.org/project/pyOpenSSL/ .. _setuptools: https://pypi.python.org/pypi/setuptools .. _AUR Scrapy package: https://aur.archlinux.org/packages/scrapy/ .. _homebrew: https://brew.sh/ diff --git a/docs/intro/tutorial.rst b/docs/intro/tutorial.rst index ee10048b5..5f35dc936 100644 --- a/docs/intro/tutorial.rst +++ b/docs/intro/tutorial.rst @@ -25,16 +25,16 @@ Scrapy. If you're already familiar with other languages, and want to learn Python quickly, the `Python Tutorial`_ is a good resource. If you're new to programming and want to start with Python, the following books -may be useful to you: +may be useful to you: * `Automate the Boring Stuff With Python`_ -* `How To Think Like a Computer Scientist`_ +* `How To Think Like a Computer Scientist`_ -* `Learn Python 3 The Hard Way`_ +* `Learn Python 3 The Hard Way`_ You can also take a look at `this list of Python resources for non-programmers`_, -as well as the `suggested resources in the learnpython-subreddit`_. +as well as the `suggested resources in the learnpython-subreddit`_. .. _Python: https://www.python.org/ .. _this list of Python resources for non-programmers: https://wiki.python.org/moin/BeginnersGuide/NonProgrammers @@ -62,7 +62,7 @@ This will create a ``tutorial`` directory with the following contents:: __init__.py items.py # project items definition file - + middlewares.py # project middlewares file pipelines.py # project pipelines file @@ -212,7 +212,7 @@ using the :ref:`Scrapy shell `. Run:: .. note:: Remember to always enclose urls in quotes when running Scrapy shell from - command-line, otherwise urls containing arguments (ie. ``&`` character) + command-line, otherwise urls containing arguments (i.e. ``&`` character) will not work. On Windows, use double quotes instead:: @@ -287,8 +287,8 @@ to be scraped, you can at least get **some** data. Besides the :meth:`~scrapy.selector.SelectorList.getall` and :meth:`~scrapy.selector.SelectorList.get` methods, you can also use -the :meth:`~scrapy.selector.SelectorList.re` method to extract using `regular -expressions`_: +the :meth:`~scrapy.selector.SelectorList.re` method to extract using +:doc:`regular expressions `: >>> response.css('title::text').re(r'Quotes.*') ['Quotes to Scrape'] @@ -305,8 +305,7 @@ with a selector (see :ref:`topics-developer-tools`). `Selector Gadget`_ is also a nice tool to quickly find CSS selector for visually selected elements, which works in many browsers. -.. _regular expressions: https://docs.python.org/3/library/re.html -.. _Selector Gadget: http://selectorgadget.com/ +.. _Selector Gadget: https://selectorgadget.com/ XPath: a brief intro @@ -337,7 +336,7 @@ recommend `this tutorial to learn XPath through examples `_, and `this tutorial to learn "how to think in XPath" `_. -.. _XPath: https://www.w3.org/TR/xpath +.. _XPath: https://www.w3.org/TR/xpath/all/ .. _CSS: https://www.w3.org/TR/selectors Extracting quotes and authors diff --git a/docs/news.rst b/docs/news.rst index 6d0d4b4ee..80d130e4a 100644 --- a/docs/news.rst +++ b/docs/news.rst @@ -3,8 +3,810 @@ Release notes ============= -.. note:: Scrapy 1.x will be the last series supporting Python 2. Scrapy 2.0, - planned for Q4 2019 or Q1 2020, will support **Python 3 only**. +.. _release-2.2.0: + +Scrapy 2.2.0 (2020-06-24) +------------------------- + +Highlights: + +* Python 3.5.2+ is required now +* :ref:`dataclass objects ` and + :ref:`attrs objects ` are now valid :ref:`item types + ` +* New :meth:`TextResponse.json ` method +* New :signal:`bytes_received` signal that allows canceling response download +* :class:`~scrapy.downloadermiddlewares.cookies.CookiesMiddleware` fixes + +Backward-incompatible changes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +* Support for Python 3.5.0 and 3.5.1 has been dropped; Scrapy now refuses to + run with a Python version lower than 3.5.2, which introduced + :class:`typing.Type` (:issue:`4615`) + + +Deprecations +~~~~~~~~~~~~ + +* :meth:`TextResponse.body_as_unicode + ` is now deprecated, use + :attr:`TextResponse.text ` instead + (:issue:`4546`, :issue:`4555`, :issue:`4579`) + +* :class:`scrapy.item.BaseItem` is now deprecated, use + :class:`scrapy.item.Item` instead (:issue:`4534`) + + +New features +~~~~~~~~~~~~ + +* :ref:`dataclass objects ` and + :ref:`attrs objects ` are now valid :ref:`item types + `, and a new itemadapter_ library makes it easy to + write code that :ref:`supports any item type ` + (:issue:`2749`, :issue:`2807`, :issue:`3761`, :issue:`3881`, :issue:`4642`) + +* A new :meth:`TextResponse.json ` method + allows to deserialize JSON responses (:issue:`2444`, :issue:`4460`, + :issue:`4574`) + +* A new :signal:`bytes_received` signal allows monitoring response download + progress and :ref:`stopping downloads ` + (:issue:`4205`, :issue:`4559`) + +* The dictionaries in the result list of a :ref:`media pipeline + ` now include a new key, ``status``, which indicates + if the file was downloaded or, if the file was not downloaded, why it was + not downloaded; see :meth:`FilesPipeline.get_media_requests + ` for more + information (:issue:`2893`, :issue:`4486`) + +* When using :ref:`Google Cloud Storage ` for + a :ref:`media pipeline `, a warning is now logged if + the configured credentials do not grant the required permissions + (:issue:`4346`, :issue:`4508`) + +* :ref:`Link extractors ` are now serializable, + as long as you do not use :ref:`lambdas ` for parameters; for + example, you can now pass link extractors in :attr:`Request.cb_kwargs + ` or + :attr:`Request.meta ` when :ref:`persisting + scheduled requests ` (:issue:`4554`) + +* Upgraded the :ref:`pickle protocol ` that Scrapy uses + from protocol 2 to protocol 4, improving serialization capabilities and + performance (:issue:`4135`, :issue:`4541`) + +* :func:`scrapy.utils.misc.create_instance` now raises a :exc:`TypeError` + exception if the resulting instance is ``None`` (:issue:`4528`, + :issue:`4532`) + +.. _itemadapter: https://github.com/scrapy/itemadapter + + +Bug fixes +~~~~~~~~~ + +* :class:`~scrapy.downloadermiddlewares.cookies.CookiesMiddleware` no longer + discards cookies defined in :attr:`Request.headers + ` (:issue:`1992`, :issue:`2400`) + +* :class:`~scrapy.downloadermiddlewares.cookies.CookiesMiddleware` no longer + re-encodes cookies defined as :class:`bytes` in the ``cookies`` parameter + of the ``__init__`` method of :class:`~scrapy.http.Request` + (:issue:`2400`, :issue:`3575`) + +* When :setting:`FEEDS` defines multiple URIs, :setting:`FEED_STORE_EMPTY` is + ``False`` and the crawl yields no items, Scrapy no longer stops feed + exports after the first URI (:issue:`4621`, :issue:`4626`) + +* :class:`~scrapy.spiders.Spider` callbacks defined using :doc:`coroutine + syntax ` no longer need to return an iterable, and may + instead return a :class:`~scrapy.http.Request` object, an + :ref:`item `, or ``None`` (:issue:`4609`) + +* The :command:`startproject` command now ensures that the generated project + folders and files have the right permissions (:issue:`4604`) + +* Fix a :exc:`KeyError` exception being sometimes raised from + :class:`scrapy.utils.datatypes.LocalWeakReferencedCache` (:issue:`4597`, + :issue:`4599`) + +* When :setting:`FEEDS` defines multiple URIs, log messages about items being + stored now contain information from the corresponding feed, instead of + always containing information about only one of the feeds (:issue:`4619`, + :issue:`4629`) + + +Documentation +~~~~~~~~~~~~~ + +* Added a new section about :ref:`accessing cb_kwargs from errbacks + ` (:issue:`4598`, :issue:`4634`) + +* Covered chompjs_ in :ref:`topics-parsing-javascript` (:issue:`4556`, + :issue:`4562`) + +* Removed from :doc:`topics/coroutines` the warning about the API being + experimental (:issue:`4511`, :issue:`4513`) + +* Removed references to unsupported versions of :doc:`Twisted + ` (:issue:`4533`) + +* Updated the description of the :ref:`screenshot pipeline example + `, which now uses :doc:`coroutine syntax + ` instead of returning a + :class:`~twisted.internet.defer.Deferred` (:issue:`4514`, :issue:`4593`) + +* Removed a misleading import line from the + :func:`scrapy.utils.log.configure_logging` code example (:issue:`4510`, + :issue:`4587`) + +* The display-on-hover behavior of internal documentation references now also + covers links to :ref:`commands `, :attr:`Request.meta + ` keys, :ref:`settings ` and + :ref:`signals ` (:issue:`4495`, :issue:`4563`) + +* It is again possible to download the documentation for offline reading + (:issue:`4578`, :issue:`4585`) + +* Removed backslashes preceding ``*args`` and ``**kwargs`` in some function + and method signatures (:issue:`4592`, :issue:`4596`) + +.. _chompjs: https://github.com/Nykakin/chompjs + + +Quality assurance +~~~~~~~~~~~~~~~~~ + +* Adjusted the code base further to our :ref:`style guidelines + ` (:issue:`4237`, :issue:`4525`, :issue:`4538`, + :issue:`4539`, :issue:`4540`, :issue:`4542`, :issue:`4543`, :issue:`4544`, + :issue:`4545`, :issue:`4557`, :issue:`4558`, :issue:`4566`, :issue:`4568`, + :issue:`4572`) + +* Removed remnants of Python 2 support (:issue:`4550`, :issue:`4553`, + :issue:`4568`) + +* Improved code sharing between the :command:`crawl` and :command:`runspider` + commands (:issue:`4548`, :issue:`4552`) + +* Replaced ``chain(*iterable)`` with ``chain.from_iterable(iterable)`` + (:issue:`4635`) + +* You may now run the :mod:`asyncio` tests with Tox on any Python version + (:issue:`4521`) + +* Updated test requirements to reflect an incompatibility with pytest 5.4 and + 5.4.1 (:issue:`4588`) + +* Improved :class:`~scrapy.spiderloader.SpiderLoader` test coverage for + scenarios involving duplicate spider names (:issue:`4549`, :issue:`4560`) + +* Configured Travis CI to also run the tests with Python 3.5.2 + (:issue:`4518`, :issue:`4615`) + +* Added a `Pylint `_ job to Travis CI + (:issue:`3727`) + +* Added a `Mypy `_ job to Travis CI (:issue:`4637`) + +* Made use of set literals in tests (:issue:`4573`) + +* Cleaned up the Travis CI configuration (:issue:`4517`, :issue:`4519`, + :issue:`4522`, :issue:`4537`) + + +.. _release-2.1.0: + +Scrapy 2.1.0 (2020-04-24) +------------------------- + +Highlights: + +* New :setting:`FEEDS` setting to export to multiple feeds +* New :attr:`Response.ip_address ` attribute + +Backward-incompatible changes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +* :exc:`AssertionError` exceptions triggered by :ref:`assert ` + statements have been replaced by new exception types, to support running + Python in optimized mode (see :option:`-O`) without changing Scrapy’s + behavior in any unexpected ways. + + If you catch an :exc:`AssertionError` exception from Scrapy, update your + code to catch the corresponding new exception. + + (:issue:`4440`) + + +Deprecation removals +~~~~~~~~~~~~~~~~~~~~ + +* The ``LOG_UNSERIALIZABLE_REQUESTS`` setting is no longer supported, use + :setting:`SCHEDULER_DEBUG` instead (:issue:`4385`) + +* The ``REDIRECT_MAX_METAREFRESH_DELAY`` setting is no longer supported, use + :setting:`METAREFRESH_MAXDELAY` instead (:issue:`4385`) + +* The :class:`~scrapy.downloadermiddlewares.chunked.ChunkedTransferMiddleware` + middleware has been removed, including the entire + :class:`scrapy.downloadermiddlewares.chunked` module; chunked transfers + work out of the box (:issue:`4431`) + +* The ``spiders`` property has been removed from + :class:`~scrapy.crawler.Crawler`, use :class:`CrawlerRunner.spider_loader + ` or instantiate + :setting:`SPIDER_LOADER_CLASS` with your settings instead (:issue:`4398`) + +* The ``MultiValueDict``, ``MultiValueDictKeyError``, and ``SiteNode`` + classes have been removed from :mod:`scrapy.utils.datatypes` + (:issue:`4400`) + + +Deprecations +~~~~~~~~~~~~ + +* The ``FEED_FORMAT`` and ``FEED_URI`` settings have been deprecated in + favor of the new :setting:`FEEDS` setting (:issue:`1336`, :issue:`3858`, + :issue:`4507`) + + +New features +~~~~~~~~~~~~ + +* A new setting, :setting:`FEEDS`, allows configuring multiple output feeds + with different settings each (:issue:`1336`, :issue:`3858`, :issue:`4507`) + +* The :command:`crawl` and :command:`runspider` commands now support multiple + ``-o`` parameters (:issue:`1336`, :issue:`3858`, :issue:`4507`) + +* The :command:`crawl` and :command:`runspider` commands now support + specifying an output format by appending ``:`` to the output file + (:issue:`1336`, :issue:`3858`, :issue:`4507`) + +* The new :attr:`Response.ip_address ` + attribute gives access to the IP address that originated a response + (:issue:`3903`, :issue:`3940`) + +* A warning is now issued when a value in + :attr:`~scrapy.spiders.Spider.allowed_domains` includes a port + (:issue:`50`, :issue:`3198`, :issue:`4413`) + +* Zsh completion now excludes used option aliases from the completion list + (:issue:`4438`) + + +Bug fixes +~~~~~~~~~ + +* :ref:`Request serialization ` no longer breaks for + callbacks that are spider attributes which are assigned a function with a + different name (:issue:`4500`) + +* ``None`` values in :attr:`~scrapy.spiders.Spider.allowed_domains` no longer + cause a :exc:`TypeError` exception (:issue:`4410`) + +* Zsh completion no longer allows options after arguments (:issue:`4438`) + +* zope.interface 5.0.0 and later versions are now supported + (:issue:`4447`, :issue:`4448`) + +* :meth:`Spider.make_requests_from_url + `, deprecated in Scrapy + 1.4.0, now issues a warning when used (:issue:`4412`) + + +Documentation +~~~~~~~~~~~~~ + +* Improved the documentation about signals that allow their handlers to + return a :class:`~twisted.internet.defer.Deferred` (:issue:`4295`, + :issue:`4390`) + +* Our PyPI entry now includes links for our documentation, our source code + repository and our issue tracker (:issue:`4456`) + +* Covered the `curl2scrapy `_ + service in the documentation (:issue:`4206`, :issue:`4455`) + +* Removed references to the Guppy library, which only works in Python 2 + (:issue:`4285`, :issue:`4343`) + +* Extended use of InterSphinx to link to Python 3 documentation + (:issue:`4444`, :issue:`4445`) + +* Added support for Sphinx 3.0 and later (:issue:`4475`, :issue:`4480`, + :issue:`4496`, :issue:`4503`) + + +Quality assurance +~~~~~~~~~~~~~~~~~ + +* Removed warnings about using old, removed settings (:issue:`4404`) + +* Removed a warning about importing + :class:`~twisted.internet.testing.StringTransport` from + ``twisted.test.proto_helpers`` in Twisted 19.7.0 or newer (:issue:`4409`) + +* Removed outdated Debian package build files (:issue:`4384`) + +* Removed :class:`object` usage as a base class (:issue:`4430`) + +* Removed code that added support for old versions of Twisted that we no + longer support (:issue:`4472`) + +* Fixed code style issues (:issue:`4468`, :issue:`4469`, :issue:`4471`, + :issue:`4481`) + +* Removed :func:`twisted.internet.defer.returnValue` calls (:issue:`4443`, + :issue:`4446`, :issue:`4489`) + + +.. _release-2.0.1: + +Scrapy 2.0.1 (2020-03-18) +------------------------- + +* :meth:`Response.follow_all ` now supports + an empty URL iterable as input (:issue:`4408`, :issue:`4420`) + +* Removed top-level :mod:`~twisted.internet.reactor` imports to prevent + errors about the wrong Twisted reactor being installed when setting a + different Twisted reactor using :setting:`TWISTED_REACTOR` (:issue:`4401`, + :issue:`4406`) + +* Fixed tests (:issue:`4422`) + + +.. _release-2.0.0: + +Scrapy 2.0.0 (2020-03-03) +------------------------- + +Highlights: + +* Python 2 support has been removed +* :doc:`Partial ` :ref:`coroutine syntax ` support + and :doc:`experimental ` :mod:`asyncio` support +* New :meth:`Response.follow_all ` method +* :ref:`FTP support ` for media pipelines +* New :attr:`Response.certificate ` + attribute +* IPv6 support through :setting:`DNS_RESOLVER` + +Backward-incompatible changes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +* Python 2 support has been removed, following `Python 2 end-of-life on + January 1, 2020`_ (:issue:`4091`, :issue:`4114`, :issue:`4115`, + :issue:`4121`, :issue:`4138`, :issue:`4231`, :issue:`4242`, :issue:`4304`, + :issue:`4309`, :issue:`4373`) + +* Retry gaveups (see :setting:`RETRY_TIMES`) are now logged as errors instead + of as debug information (:issue:`3171`, :issue:`3566`) + +* File extensions that + :class:`LinkExtractor ` + ignores by default now also include ``7z``, ``7zip``, ``apk``, ``bz2``, + ``cdr``, ``dmg``, ``ico``, ``iso``, ``tar``, ``tar.gz``, ``webm``, and + ``xz`` (:issue:`1837`, :issue:`2067`, :issue:`4066`) + +* The :setting:`METAREFRESH_IGNORE_TAGS` setting is now an empty list by + default, following web browser behavior (:issue:`3844`, :issue:`4311`) + +* The + :class:`~scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware` + now includes spaces after commas in the value of the ``Accept-Encoding`` + header that it sets, following web browser behavior (:issue:`4293`) + +* The ``__init__`` method of custom download handlers (see + :setting:`DOWNLOAD_HANDLERS`) or subclasses of the following downloader + handlers no longer receives a ``settings`` parameter: + + * :class:`scrapy.core.downloader.handlers.datauri.DataURIDownloadHandler` + + * :class:`scrapy.core.downloader.handlers.file.FileDownloadHandler` + + Use the ``from_settings`` or ``from_crawler`` class methods to expose such + a parameter to your custom download handlers. + + (:issue:`4126`) + +* We have refactored the :class:`scrapy.core.scheduler.Scheduler` class and + related queue classes (see :setting:`SCHEDULER_PRIORITY_QUEUE`, + :setting:`SCHEDULER_DISK_QUEUE` and :setting:`SCHEDULER_MEMORY_QUEUE`) to + make it easier to implement custom scheduler queue classes. See + :ref:`2-0-0-scheduler-queue-changes` below for details. + +* Overridden settings are now logged in a different format. This is more in + line with similar information logged at startup (:issue:`4199`) + +.. _Python 2 end-of-life on January 1, 2020: https://www.python.org/doc/sunset-python-2/ + + +Deprecation removals +~~~~~~~~~~~~~~~~~~~~ + +* The :ref:`Scrapy shell ` no longer provides a `sel` proxy + object, use :meth:`response.selector ` + instead (:issue:`4347`) + +* LevelDB support has been removed (:issue:`4112`) + +* The following functions have been removed from :mod:`scrapy.utils.python`: + ``isbinarytext``, ``is_writable``, ``setattr_default``, ``stringify_dict`` + (:issue:`4362`) + + +Deprecations +~~~~~~~~~~~~ + +* Using environment variables prefixed with ``SCRAPY_`` to override settings + is deprecated (:issue:`4300`, :issue:`4374`, :issue:`4375`) + +* :class:`scrapy.linkextractors.FilteringLinkExtractor` is deprecated, use + :class:`scrapy.linkextractors.LinkExtractor + ` instead (:issue:`4045`) + +* The ``noconnect`` query string argument of proxy URLs is deprecated and + should be removed from proxy URLs (:issue:`4198`) + +* The :meth:`next ` method of + :class:`scrapy.utils.python.MutableChain` is deprecated, use the global + :func:`next` function or :meth:`MutableChain.__next__ + ` instead (:issue:`4153`) + + +New features +~~~~~~~~~~~~ + +* Added :doc:`partial support ` for Python’s + :ref:`coroutine syntax ` and :doc:`experimental support + ` for :mod:`asyncio` and :mod:`asyncio`-powered libraries + (:issue:`4010`, :issue:`4259`, :issue:`4269`, :issue:`4270`, :issue:`4271`, + :issue:`4316`, :issue:`4318`) + +* The new :meth:`Response.follow_all ` + method offers the same functionality as + :meth:`Response.follow ` but supports an + iterable of URLs as input and returns an iterable of requests + (:issue:`2582`, :issue:`4057`, :issue:`4286`) + +* :ref:`Media pipelines ` now support :ref:`FTP + storage ` (:issue:`3928`, :issue:`3961`) + +* The new :attr:`Response.certificate ` + attribute exposes the SSL certificate of the server as a + :class:`twisted.internet.ssl.Certificate` object for HTTPS responses + (:issue:`2726`, :issue:`4054`) + +* A new :setting:`DNS_RESOLVER` setting allows enabling IPv6 support + (:issue:`1031`, :issue:`4227`) + +* A new :setting:`SCRAPER_SLOT_MAX_ACTIVE_SIZE` setting allows configuring + the existing soft limit that pauses request downloads when the total + response data being processed is too high (:issue:`1410`, :issue:`3551`) + +* A new :setting:`TWISTED_REACTOR` setting allows customizing the + :mod:`~twisted.internet.reactor` that Scrapy uses, allowing to + :doc:`enable asyncio support ` or deal with a + :ref:`common macOS issue ` (:issue:`2905`, + :issue:`4294`) + +* Scheduler disk and memory queues may now use the class methods + ``from_crawler`` or ``from_settings`` (:issue:`3884`) + +* The new :attr:`Response.cb_kwargs ` + attribute serves as a shortcut for :attr:`Response.request.cb_kwargs + ` (:issue:`4331`) + +* :meth:`Response.follow ` now supports a + ``flags`` parameter, for consistency with :class:`~scrapy.http.Request` + (:issue:`4277`, :issue:`4279`) + +* :ref:`Item loader processors ` can now be + regular functions, they no longer need to be methods (:issue:`3899`) + +* :class:`~scrapy.spiders.Rule` now accepts an ``errback`` parameter + (:issue:`4000`) + +* :class:`~scrapy.http.Request` no longer requires a ``callback`` parameter + when an ``errback`` parameter is specified (:issue:`3586`, :issue:`4008`) + +* :class:`~scrapy.logformatter.LogFormatter` now supports some additional + methods: + + * :class:`~scrapy.logformatter.LogFormatter.download_error` for + download errors + + * :class:`~scrapy.logformatter.LogFormatter.item_error` for exceptions + raised during item processing by :ref:`item pipelines + ` + + * :class:`~scrapy.logformatter.LogFormatter.spider_error` for exceptions + raised from :ref:`spider callbacks ` + + (:issue:`374`, :issue:`3986`, :issue:`3989`, :issue:`4176`, :issue:`4188`) + +* The :setting:`FEED_URI` setting now supports :class:`pathlib.Path` values + (:issue:`3731`, :issue:`4074`) + +* A new :signal:`request_left_downloader` signal is sent when a request + leaves the downloader (:issue:`4303`) + +* Scrapy logs a warning when it detects a request callback or errback that + uses ``yield`` but also returns a value, since the returned value would be + lost (:issue:`3484`, :issue:`3869`) + +* :class:`~scrapy.spiders.Spider` objects now raise an :exc:`AttributeError` + exception if they do not have a :class:`~scrapy.spiders.Spider.start_urls` + attribute nor reimplement :class:`~scrapy.spiders.Spider.start_requests`, + but have a ``start_url`` attribute (:issue:`4133`, :issue:`4170`) + +* :class:`~scrapy.exporters.BaseItemExporter` subclasses may now use + ``super().__init__(**kwargs)`` instead of ``self._configure(kwargs)`` in + their ``__init__`` method, passing ``dont_fail=True`` to the parent + ``__init__`` method if needed, and accessing ``kwargs`` at ``self._kwargs`` + after calling their parent ``__init__`` method (:issue:`4193`, + :issue:`4370`) + +* A new ``keep_fragments`` parameter of + :func:`scrapy.utils.request.request_fingerprint` allows to generate + different fingerprints for requests with different fragments in their URL + (:issue:`4104`) + +* Download handlers (see :setting:`DOWNLOAD_HANDLERS`) may now use the + ``from_settings`` and ``from_crawler`` class methods that other Scrapy + components already supported (:issue:`4126`) + +* :class:`scrapy.utils.python.MutableChain.__iter__` now returns ``self``, + `allowing it to be used as a sequence `_ + (:issue:`4153`) + + +Bug fixes +~~~~~~~~~ + +* The :command:`crawl` command now also exits with exit code 1 when an + exception happens before the crawling starts (:issue:`4175`, :issue:`4207`) + +* :class:`LinkExtractor.extract_links + ` no longer + re-encodes the query string or URLs from non-UTF-8 responses in UTF-8 + (:issue:`998`, :issue:`1403`, :issue:`1949`, :issue:`4321`) + +* The first spider middleware (see :setting:`SPIDER_MIDDLEWARES`) now also + processes exceptions raised from callbacks that are generators + (:issue:`4260`, :issue:`4272`) + +* Redirects to URLs starting with 3 slashes (``///``) are now supported + (:issue:`4032`, :issue:`4042`) + +* :class:`~scrapy.http.Request` no longer accepts strings as ``url`` simply + because they have a colon (:issue:`2552`, :issue:`4094`) + +* The correct encoding is now used for attach names in + :class:`~scrapy.mail.MailSender` (:issue:`4229`, :issue:`4239`) + +* :class:`~scrapy.dupefilters.RFPDupeFilter`, the default + :setting:`DUPEFILTER_CLASS`, no longer writes an extra ``\r`` character on + each line in Windows, which made the size of the ``requests.seen`` file + unnecessarily large on that platform (:issue:`4283`) + +* Z shell auto-completion now looks for ``.html`` files, not ``.http`` files, + and covers the ``-h`` command-line switch (:issue:`4122`, :issue:`4291`) + +* Adding items to a :class:`scrapy.utils.datatypes.LocalCache` object + without a ``limit`` defined no longer raises a :exc:`TypeError` exception + (:issue:`4123`) + +* Fixed a typo in the message of the :exc:`ValueError` exception raised when + :func:`scrapy.utils.misc.create_instance` gets both ``settings`` and + ``crawler`` set to ``None`` (:issue:`4128`) + + +Documentation +~~~~~~~~~~~~~ + +* API documentation now links to an online, syntax-highlighted view of the + corresponding source code (:issue:`4148`) + +* Links to unexisting documentation pages now allow access to the sidebar + (:issue:`4152`, :issue:`4169`) + +* Cross-references within our documentation now display a tooltip when + hovered (:issue:`4173`, :issue:`4183`) + +* Improved the documentation about :meth:`LinkExtractor.extract_links + ` and + simplified :ref:`topics-link-extractors` (:issue:`4045`) + +* Clarified how :class:`ItemLoader.item ` + works (:issue:`3574`, :issue:`4099`) + +* Clarified that :func:`logging.basicConfig` should not be used when also + using :class:`~scrapy.crawler.CrawlerProcess` (:issue:`2149`, + :issue:`2352`, :issue:`3146`, :issue:`3960`) + +* Clarified the requirements for :class:`~scrapy.http.Request` objects + :ref:`when using persistence ` (:issue:`4124`, + :issue:`4139`) + +* Clarified how to install a :ref:`custom image pipeline + ` (:issue:`4034`, :issue:`4252`) + +* Fixed the signatures of the ``file_path`` method in :ref:`media pipeline + ` examples (:issue:`4290`) + +* Covered a backward-incompatible change in Scrapy 1.7.0 affecting custom + :class:`scrapy.core.scheduler.Scheduler` subclasses (:issue:`4274`) + +* Improved the ``README.rst`` and ``CODE_OF_CONDUCT.md`` files + (:issue:`4059`) + +* Documentation examples are now checked as part of our test suite and we + have fixed some of the issues detected (:issue:`4142`, :issue:`4146`, + :issue:`4171`, :issue:`4184`, :issue:`4190`) + +* Fixed logic issues, broken links and typos (:issue:`4247`, :issue:`4258`, + :issue:`4282`, :issue:`4288`, :issue:`4305`, :issue:`4308`, :issue:`4323`, + :issue:`4338`, :issue:`4359`, :issue:`4361`) + +* Improved consistency when referring to the ``__init__`` method of an object + (:issue:`4086`, :issue:`4088`) + +* Fixed an inconsistency between code and output in :ref:`intro-overview` + (:issue:`4213`) + +* Extended :mod:`~sphinx.ext.intersphinx` usage (:issue:`4147`, + :issue:`4172`, :issue:`4185`, :issue:`4194`, :issue:`4197`) + +* We now use a recent version of Python to build the documentation + (:issue:`4140`, :issue:`4249`) + +* Cleaned up documentation (:issue:`4143`, :issue:`4275`) + + +Quality assurance +~~~~~~~~~~~~~~~~~ + +* Re-enabled proxy ``CONNECT`` tests (:issue:`2545`, :issue:`4114`) + +* Added Bandit_ security checks to our test suite (:issue:`4162`, + :issue:`4181`) + +* Added Flake8_ style checks to our test suite and applied many of the + corresponding changes (:issue:`3944`, :issue:`3945`, :issue:`4137`, + :issue:`4157`, :issue:`4167`, :issue:`4174`, :issue:`4186`, :issue:`4195`, + :issue:`4238`, :issue:`4246`, :issue:`4355`, :issue:`4360`, :issue:`4365`) + +* Improved test coverage (:issue:`4097`, :issue:`4218`, :issue:`4236`) + +* Started reporting slowest tests, and improved the performance of some of + them (:issue:`4163`, :issue:`4164`) + +* Fixed broken tests and refactored some tests (:issue:`4014`, :issue:`4095`, + :issue:`4244`, :issue:`4268`, :issue:`4372`) + +* Modified the :doc:`tox ` configuration to allow running tests + with any Python version, run Bandit_ and Flake8_ tests by default, and + enforce a minimum tox version programmatically (:issue:`4179`) + +* Cleaned up code (:issue:`3937`, :issue:`4208`, :issue:`4209`, + :issue:`4210`, :issue:`4212`, :issue:`4369`, :issue:`4376`, :issue:`4378`) + +.. _Bandit: https://bandit.readthedocs.io/ +.. _Flake8: https://flake8.pycqa.org/en/latest/ + + +.. _2-0-0-scheduler-queue-changes: + +Changes to scheduler queue classes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The following changes may impact any custom queue classes of all types: + +* The ``push`` method no longer receives a second positional parameter + containing ``request.priority * -1``. If you need that value, get it + from the first positional parameter, ``request``, instead, or use + the new :meth:`~scrapy.core.scheduler.ScrapyPriorityQueue.priority` + method in :class:`scrapy.core.scheduler.ScrapyPriorityQueue` + subclasses. + +The following changes may impact custom priority queue classes: + +* In the ``__init__`` method or the ``from_crawler`` or ``from_settings`` + class methods: + + * The parameter that used to contain a factory function, + ``qfactory``, is now passed as a keyword parameter named + ``downstream_queue_cls``. + + * A new keyword parameter has been added: ``key``. It is a string + that is always an empty string for memory queues and indicates the + :setting:`JOB_DIR` value for disk queues. + + * The parameter for disk queues that contains data from the previous + crawl, ``startprios`` or ``slot_startprios``, is now passed as a + keyword parameter named ``startprios``. + + * The ``serialize`` parameter is no longer passed. The disk queue + class must take care of request serialization on its own before + writing to disk, using the + :func:`~scrapy.utils.reqser.request_to_dict` and + :func:`~scrapy.utils.reqser.request_from_dict` functions from the + :mod:`scrapy.utils.reqser` module. + +The following changes may impact custom disk and memory queue classes: + +* The signature of the ``__init__`` method is now + ``__init__(self, crawler, key)``. + +The following changes affect specifically the +:class:`~scrapy.core.scheduler.ScrapyPriorityQueue` and +:class:`~scrapy.core.scheduler.DownloaderAwarePriorityQueue` classes from +:mod:`scrapy.core.scheduler` and may affect subclasses: + +* In the ``__init__`` method, most of the changes described above apply. + + ``__init__`` may still receive all parameters as positional parameters, + however: + + * ``downstream_queue_cls``, which replaced ``qfactory``, must be + instantiated differently. + + ``qfactory`` was instantiated with a priority value (integer). + + Instances of ``downstream_queue_cls`` should be created using + the new + :meth:`ScrapyPriorityQueue.qfactory ` + or + :meth:`DownloaderAwarePriorityQueue.pqfactory ` + methods. + + * The new ``key`` parameter displaced the ``startprios`` + parameter 1 position to the right. + +* The following class attributes have been added: + + * :attr:`~scrapy.core.scheduler.ScrapyPriorityQueue.crawler` + + * :attr:`~scrapy.core.scheduler.ScrapyPriorityQueue.downstream_queue_cls` + (details above) + + * :attr:`~scrapy.core.scheduler.ScrapyPriorityQueue.key` (details above) + +* The ``serialize`` attribute has been removed (details above) + +The following changes affect specifically the +:class:`~scrapy.core.scheduler.ScrapyPriorityQueue` class and may affect +subclasses: + +* A new :meth:`~scrapy.core.scheduler.ScrapyPriorityQueue.priority` + method has been added which, given a request, returns + ``request.priority * -1``. + + It is used in :meth:`~scrapy.core.scheduler.ScrapyPriorityQueue.push` + to make up for the removal of its ``priority`` parameter. + +* The ``spider`` attribute has been removed. Use + :attr:`crawler.spider ` + instead. + +The following changes affect specifically the +:class:`~scrapy.core.scheduler.DownloaderAwarePriorityQueue` class and may +affect subclasses: + +* A new :attr:`~scrapy.core.scheduler.DownloaderAwarePriorityQueue.pqueues` + attribute offers a mapping of downloader slot names to the + corresponding instances of + :attr:`~scrapy.core.scheduler.DownloaderAwarePriorityQueue.downstream_queue_cls`. + +(:issue:`3884`) + .. _release-1.8.0: @@ -26,7 +828,7 @@ Backward-incompatible changes * Python 3.4 is no longer supported, and some of the minimum requirements of Scrapy have also changed: - * cssselect_ 0.9.1 + * :doc:`cssselect ` 0.9.1 * cryptography_ 2.0 * lxml_ 3.5.0 * pyOpenSSL_ 16.2.0 @@ -288,6 +1090,13 @@ Backward-incompatible changes :class:`~scrapy.http.Request` objects instead of arbitrary Python data structures. +* An additional ``crawler`` parameter has been added to the ``__init__`` + method of the :class:`~scrapy.core.scheduler.Scheduler` class. Custom + scheduler subclasses which don't accept arbitrary parameters in their + ``__init__`` method might break because of this change. + + For more information, see :setting:`SCHEDULER`. + See also :ref:`1.7-deprecation-removals` below. @@ -1069,7 +1878,7 @@ Cleanups & Refactoring ~~~~~~~~~~~~~~~~~~~~~~ - Tests: remove temp files and folders (:issue:`2570`), - fixed ProjectUtilsTest on OS X (:issue:`2569`), + fixed ProjectUtilsTest on macOS (:issue:`2569`), use portable pypy for Linux on Travis CI (:issue:`2710`) - Separate building request from ``_requests_to_follow`` in CrawlSpider (:issue:`2562`) - Remove “Python 3 progress” badge (:issue:`2567`) @@ -1609,7 +2418,7 @@ Deprecations and Removals + ``scrapy.utils.datatypes.SiteNode`` - The previously bundled ``scrapy.xlib.pydispatch`` library was deprecated and - replaced by `pydispatcher `_. + replaced by `pydispatcher `_. Relocations @@ -1638,7 +2447,7 @@ Bugfixes - Makes ``_monkeypatches`` more robust (:issue:`1634`). - Fixed bug on ``XMLItemExporter`` with non-string fields in items (:issue:`1738`). -- Fixed startproject command in OS X (:issue:`1635`). +- Fixed startproject command in macOS (:issue:`1635`). - Fixed :class:`~scrapy.exporters.PythonItemExporter` and CSVExporter for non-string item types (:issue:`1737`). - Various logging related fixes (:issue:`1294`, :issue:`1419`, :issue:`1263`, @@ -1706,12 +2515,12 @@ Scrapy 1.0.4 (2015-12-30) - Typos corrections (:commit:`7067117`) - fix typos in downloader-middleware.rst and exceptions.rst, middlware -> middleware (:commit:`32f115c`) - Add note to Ubuntu install section about Debian compatibility (:commit:`23fda69`) -- Replace alternative OSX install workaround with virtualenv (:commit:`98b63ee`) +- Replace alternative macOS install workaround with virtualenv (:commit:`98b63ee`) - Reference Homebrew's homepage for installation instructions (:commit:`1925db1`) - Add oldest supported tox version to contributing docs (:commit:`5d10d6d`) - Note in install docs about pip being already included in python>=2.7.9 (:commit:`85c980e`) - Add non-python dependencies to Ubuntu install section in the docs (:commit:`fbd010d`) -- Add OS X installation section to docs (:commit:`d8f4cba`) +- Add macOS installation section to docs (:commit:`d8f4cba`) - DOC(ENH): specify path to rtd theme explicitly (:commit:`de73b1a`) - minor: scrapy.Spider docs grammar (:commit:`1ddcc7b`) - Make common practices sample code match the comments (:commit:`1b85bcf`) @@ -2443,7 +3252,7 @@ Other ~~~~~ - Dropped Python 2.6 support (:issue:`448`) -- Add `cssselect`_ python package as install dependency +- Add :doc:`cssselect ` python package as install dependency - Drop libxml2 and multi selector's backend support, `lxml`_ is required from now on. - Minimum Twisted version increased to 10.0.0, dropped Twisted 8.0 support. - Running test suite now requires ``mock`` python library (:issue:`390`) @@ -2564,7 +3373,7 @@ Scrapy 0.18.0 (released 2013-08-09) - MetaRefreshMiddldeware and RedirectMiddleware have different priorities to address #62 - added from_crawler method to spiders - added system tests with mock server -- more improvements to Mac OS compatibility (thanks Alex Cepoi) +- more improvements to macOS compatibility (thanks Alex Cepoi) - several more cleanups to singletons and multi-spider support (thanks Nicolas Ramirez) - support custom download slots - added --spider option to "shell" command. @@ -2640,7 +3449,7 @@ Scrapy 0.16.3 (released 2012-12-07) - Remove concurrency limitation when using download delays and still ensure inter-request delays are enforced (:commit:`487b9b5`) - add error details when image pipeline fails (:commit:`8232569`) -- improve mac os compatibility (:commit:`8dcf8aa`) +- improve macOS compatibility (:commit:`8dcf8aa`) - setup.py: use README.rst to populate long_description (:commit:`7b5310d`) - doc: removed obsolete references to ClientForm (:commit:`80f9bb6`) - correct docs for default storage backend (:commit:`2aa491b`) @@ -3040,17 +3849,16 @@ Scrapy 0.7 First release of Scrapy. -.. _AJAX crawleable urls: https://developers.google.com/webmasters/ajax-crawling/docs/getting-started?csw=1 +.. _AJAX crawleable urls: https://developers.google.com/search/docs/ajax-crawling/docs/getting-started?csw=1 .. _botocore: https://github.com/boto/botocore .. _chunked transfer encoding: https://en.wikipedia.org/wiki/Chunked_transfer_encoding .. _ClientForm: http://wwwsearch.sourceforge.net/old/ClientForm/ .. _Creating a pull request: https://help.github.com/en/articles/creating-a-pull-request .. _cryptography: https://cryptography.io/en/latest/ -.. _cssselect: https://github.com/scrapy/cssselect/ -.. _docstrings: https://docs.python.org/glossary.html#term-docstring -.. _KeyboardInterrupt: https://docs.python.org/library/exceptions.html#KeyboardInterrupt +.. _docstrings: https://docs.python.org/3/glossary.html#term-docstring +.. _KeyboardInterrupt: https://docs.python.org/3/library/exceptions.html#KeyboardInterrupt .. _LevelDB: https://github.com/google/leveldb -.. _lxml: http://lxml.de/ +.. _lxml: https://lxml.de/ .. _marshal: https://docs.python.org/2/library/marshal.html .. _parsel.csstranslator.GenericTranslator: https://parsel.readthedocs.io/en/latest/parsel.html#parsel.csstranslator.GenericTranslator .. _parsel.csstranslator.HTMLTranslator: https://parsel.readthedocs.io/en/latest/parsel.html#parsel.csstranslator.HTMLTranslator @@ -3061,11 +3869,11 @@ First release of Scrapy. .. _queuelib: https://github.com/scrapy/queuelib .. _registered with IANA: https://www.iana.org/assignments/media-types/media-types.xhtml .. _resource: https://docs.python.org/2/library/resource.html -.. _robots.txt: http://www.robotstxt.org/ +.. _robots.txt: https://www.robotstxt.org/ .. _scrapely: https://github.com/scrapy/scrapely .. _service_identity: https://service-identity.readthedocs.io/en/stable/ .. _six: https://six.readthedocs.io/ -.. _tox: https://pypi.python.org/pypi/tox +.. _tox: https://pypi.org/project/tox/ .. _Twisted: https://twistedmatrix.com/trac/ .. _Twisted - hello, asynchronous programming: http://jessenoller.com/blog/2009/02/11/twisted-hello-asynchronous-programming/ .. _w3lib: https://github.com/scrapy/w3lib diff --git a/docs/requirements.txt b/docs/requirements.txt index 773b92cea..3d34b47da 100644 --- a/docs/requirements.txt +++ b/docs/requirements.txt @@ -1,4 +1,4 @@ -Sphinx>=2.1 -sphinx-hoverxref -sphinx-notfound-page -sphinx_rtd_theme +Sphinx>=3.0 +sphinx-hoverxref>=0.2b1 +sphinx-notfound-page>=0.4 +sphinx_rtd_theme>=0.4 diff --git a/docs/topics/api.rst b/docs/topics/api.rst index 1c461a511..52509ffdf 100644 --- a/docs/topics/api.rst +++ b/docs/topics/api.rst @@ -91,7 +91,7 @@ how you :ref:`configure the downloader middlewares provided while constructing the crawler, and it is created after the arguments given in the :meth:`crawl` method. - .. method:: crawl(\*args, \**kwargs) + .. method:: crawl(*args, **kwargs) Starts the crawler by instantiating its spider class with the given ``args`` and ``kwargs`` arguments, while setting the execution engine in diff --git a/docs/topics/architecture.rst b/docs/topics/architecture.rst index ae25dfa2f..074c59241 100644 --- a/docs/topics/architecture.rst +++ b/docs/topics/architecture.rst @@ -104,7 +104,7 @@ Spiders ------- Spiders are custom classes written by Scrapy users to parse responses and -extract items (aka scraped items) from them or additional requests to +extract :ref:`items ` from them or additional requests to follow. For more information see :ref:`topics-spiders`. .. _component-pipelines: diff --git a/docs/topics/asyncio.rst b/docs/topics/asyncio.rst new file mode 100644 index 000000000..038a459fd --- /dev/null +++ b/docs/topics/asyncio.rst @@ -0,0 +1,28 @@ +======= +asyncio +======= + +.. versionadded:: 2.0 + +Scrapy has partial support :mod:`asyncio`. After you :ref:`install the asyncio +reactor `, you may use :mod:`asyncio` and +:mod:`asyncio`-powered libraries in any :doc:`coroutine `. + +.. warning:: :mod:`asyncio` support in Scrapy is experimental. Future Scrapy + versions may introduce related changes without a deprecation + period or warning. + +.. _install-asyncio: + +Installing the asyncio reactor +============================== + +To enable :mod:`asyncio` support, set the :setting:`TWISTED_REACTOR` setting to +``'twisted.internet.asyncioreactor.AsyncioSelectorReactor'``. + +If you are using :class:`~scrapy.crawler.CrawlerRunner`, you also need to +install the :class:`~twisted.internet.asyncioreactor.AsyncioSelectorReactor` +reactor manually. You can do that using +:func:`~scrapy.utils.reactor.install_reactor`:: + + install_reactor('twisted.internet.asyncioreactor.AsyncioSelectorReactor') diff --git a/docs/topics/broad-crawls.rst b/docs/topics/broad-crawls.rst index 1ab08d949..63b60312e 100644 --- a/docs/topics/broad-crawls.rst +++ b/docs/topics/broad-crawls.rst @@ -188,7 +188,7 @@ AjaxCrawlMiddleware helps to crawl them correctly. 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 +.. _ajax crawlable: https://developers.google.com/search/docs/ajax-crawling/docs/getting-started .. _broad-crawls-bfo: @@ -211,3 +211,10 @@ If your broad crawl shows a high memory usage, in addition to :ref:`crawling in BFO order ` and :ref:`lowering concurrency ` you should :ref:`debug your memory 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. diff --git a/docs/topics/contracts.rst b/docs/topics/contracts.rst index 43db8f101..b8b3078c4 100644 --- a/docs/topics/contracts.rst +++ b/docs/topics/contracts.rst @@ -78,7 +78,7 @@ override three methods: .. module:: scrapy.contracts -.. class:: Contract(method, \*args) +.. class:: Contract(method, *args) :param method: callback function to which the contract is associated :type method: function @@ -136,7 +136,7 @@ Detecting check runs ==================== When ``scrapy check`` is running, the ``SCRAPY_CHECK`` environment variable is -set to the ``true`` string. You can use `os.environ`_ to perform any change to +set to the ``true`` string. You can use :data:`os.environ` to perform any change to your spiders or your settings when ``scrapy check`` is used:: import os @@ -148,5 +148,3 @@ your spiders or your settings when ``scrapy check`` is used:: def __init__(self): if os.environ.get('SCRAPY_CHECK'): pass # Do some scraper adjustments when a check is running - -.. _os.environ: https://docs.python.org/3/library/os.html#os.environ diff --git a/docs/topics/coroutines.rst b/docs/topics/coroutines.rst new file mode 100644 index 000000000..a0952d323 --- /dev/null +++ b/docs/topics/coroutines.rst @@ -0,0 +1,112 @@ +========== +Coroutines +========== + +.. versionadded:: 2.0 + +Scrapy has :ref:`partial support ` for the +:ref:`coroutine syntax `. + +.. _coroutine-support: + +Supported callables +=================== + +The following callables may be defined as coroutines using ``async def``, and +hence use coroutine syntax (e.g. ``await``, ``async for``, ``async with``): + +- :class:`~scrapy.http.Request` callbacks. + + The following are known caveats of the current implementation that we aim + to address in future versions of Scrapy: + + - The callback output is not processed until the whole callback finishes. + + As a side effect, if the callback raises an exception, none of its + output is processed. + + - Because `asynchronous generators were introduced in Python 3.6`_, you + can only use ``yield`` if you are using Python 3.6 or later. + + If you need to output multiple items or requests and you are using + Python 3.5, return an iterable (e.g. a list) instead. + +- The :meth:`process_item` method of + :ref:`item pipelines `. + +- The + :meth:`~scrapy.downloadermiddlewares.DownloaderMiddleware.process_request`, + :meth:`~scrapy.downloadermiddlewares.DownloaderMiddleware.process_response`, + and + :meth:`~scrapy.downloadermiddlewares.DownloaderMiddleware.process_exception` + methods of + :ref:`downloader middlewares `. + +- :ref:`Signal handlers that support deferreds `. + +.. _asynchronous generators were introduced in Python 3.6: https://www.python.org/dev/peps/pep-0525/ + +Usage +===== + +There are several use cases for coroutines in Scrapy. Code that would +return Deferreds when written for previous Scrapy versions, such as downloader +middlewares and signal handlers, can be rewritten to be shorter and cleaner:: + + from itemadapter import ItemAdapter + + class DbPipeline: + def _update_item(self, data, item): + adapter = ItemAdapter(item) + adapter['field'] = data + return item + + def process_item(self, item, spider): + adapter = ItemAdapter(item) + dfd = db.get_some_data(adapter['id']) + dfd.addCallback(self._update_item, item) + return dfd + +becomes:: + + from itemadapter import ItemAdapter + + class DbPipeline: + async def process_item(self, item, spider): + adapter = ItemAdapter(item) + adapter['field'] = await db.get_some_data(adapter['id']) + return item + +Coroutines may be used to call asynchronous code. This includes other +coroutines, functions that return Deferreds and functions that return +:term:`awaitable objects ` such as :class:`~asyncio.Future`. +This means you can use many useful Python libraries providing such code:: + + class MySpider(Spider): + # ... + async def parse_with_deferred(self, response): + additional_response = await treq.get('https://additional.url') + additional_data = await treq.content(additional_response) + # ... use response and additional_data to yield items and requests + + async def parse_with_asyncio(self, response): + async with aiohttp.ClientSession() as session: + async with session.get('https://additional.url') as additional_response: + additional_data = await r.text() + # ... use response and additional_data to yield items and requests + +.. note:: Many libraries that use coroutines, such as `aio-libs`_, require the + :mod:`asyncio` loop and to use them you need to + :doc:`enable asyncio support in Scrapy`. + +Common use cases for asynchronous code include: + +* requesting data from websites, databases and other services (in callbacks, + pipelines and middlewares); +* storing data in databases (in pipelines and middlewares); +* delaying the spider initialization until some external event (in the + :signal:`spider_opened` handler); +* calling asynchronous Scrapy methods like ``ExecutionEngine.download`` (see + :ref:`the screenshot pipeline example`). + +.. _aio-libs: https://github.com/aio-libs diff --git a/docs/topics/developer-tools.rst b/docs/topics/developer-tools.rst index b7d740c19..4e87a00f2 100644 --- a/docs/topics/developer-tools.rst +++ b/docs/topics/developer-tools.rst @@ -142,7 +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 ` to @@ -292,6 +292,9 @@ 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. +Note that to translate a cURL command into a Scrapy request, +you may use `curl2scrapy `_. + As you can see, with a few inspections in the `Network`-tool we were able to easily replicate the dynamic requests of the scrolling functionality of the page. Crawling dynamic pages can be quite diff --git a/docs/topics/downloader-middleware.rst b/docs/topics/downloader-middleware.rst index 8a760e53b..323e553e5 100644 --- a/docs/topics/downloader-middleware.rst +++ b/docs/topics/downloader-middleware.rst @@ -202,6 +202,11 @@ CookiesMiddleware sends them back on subsequent requests (from that spider), just like web browsers do. + .. caution:: When non-UTF8 encoded byte sequences are passed to a + :class:`~scrapy.http.Request`, the ``CookiesMiddleware`` will log + a warning. Refer to :ref:`topics-logging-advanced-customization` + to customize the logging behaviour. + The following settings can be used to configure the cookie middleware: * :setting:`COOKIES_ENABLED` @@ -259,8 +264,8 @@ COOKIES_DEBUG Default: ``False`` -If enabled, Scrapy will log all cookies sent in requests (ie. ``Cookie`` -header) and all cookies received in responses (ie. ``Set-Cookie`` header). +If enabled, Scrapy will log all cookies sent in requests (i.e. ``Cookie`` +header) and all cookies received in responses (i.e. ``Set-Cookie`` header). Here's an example of a log with :setting:`COOKIES_DEBUG` enabled:: @@ -709,7 +714,7 @@ HttpCompressionMiddleware provided `brotlipy`_ is installed. .. _brotli-compressed: https://www.ietf.org/rfc/rfc7932.txt -.. _brotlipy: https://pypi.python.org/pypi/brotlipy +.. _brotlipy: https://pypi.org/project/brotlipy/ HttpCompressionMiddleware Settings ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -739,7 +744,7 @@ HttpProxyMiddleware This middleware sets the HTTP proxy to use for requests, by setting the ``proxy`` meta value for :class:`~scrapy.http.Request` objects. - Like the Python standard library modules `urllib`_ and `urllib2`_, it obeys + Like the Python standard library module :mod:`urllib.request`, it obeys the following environment variables: * ``http_proxy`` @@ -751,9 +756,6 @@ HttpProxyMiddleware Keep in mind this value will take precedence over ``http_proxy``/``https_proxy`` environment variables, and it will also ignore ``no_proxy`` environment variable. -.. _urllib: https://docs.python.org/2/library/urllib.html -.. _urllib2: https://docs.python.org/2/library/urllib2.html - RedirectMiddleware ------------------ @@ -829,6 +831,7 @@ REDIRECT_MAX_TIMES Default: ``20`` The maximum number of redirections that will be followed for a single request. +After this maximum, the request's response is returned as is. MetaRefreshMiddleware --------------------- @@ -868,10 +871,14 @@ Whether the Meta Refresh middleware will be enabled. METAREFRESH_IGNORE_TAGS ^^^^^^^^^^^^^^^^^^^^^^^ -Default: ``['script', 'noscript']`` +Default: ``[]`` Meta tags within these tags are ignored. +.. versionchanged:: 2.0 + The default value of :setting:`METAREFRESH_IGNORE_TAGS` changed from + ``['script', 'noscript']`` to ``[]``. + .. setting:: METAREFRESH_MAXDELAY METAREFRESH_MAXDELAY @@ -1032,13 +1039,12 @@ Scrapy uses this parser by default. RobotFileParser ~~~~~~~~~~~~~~~ -Based on `RobotFileParser -`_: +Based on :class:`~urllib.robotparser.RobotFileParser`: * is Python's built-in robots.txt_ parser * is compliant with `Martijn Koster's 1996 draft specification - `_ + `_ * lacks support for wildcard matching @@ -1061,7 +1067,7 @@ Based on `Reppy `_: `_ * is compliant with `Martijn Koster's 1996 draft specification - `_ + `_ * supports wildcard matching @@ -1086,7 +1092,7 @@ Based on `Robotexclusionrulesparser `_: * implemented in Python * is compliant with `Martijn Koster's 1996 draft specification - `_ + `_ * supports wildcard matching @@ -1115,7 +1121,7 @@ implementing the methods described below. .. autoclass:: RobotParser :members: -.. _robots.txt: http://www.robotstxt.org/ +.. _robots.txt: https://www.robotstxt.org/ DownloaderStats --------------- @@ -1155,7 +1161,7 @@ AjaxCrawlMiddleware Middleware that finds 'AJAX crawlable' page variants based on meta-fragment html tag. See - https://developers.google.com/webmasters/ajax-crawling/docs/getting-started + https://developers.google.com/search/docs/ajax-crawling/docs/getting-started for more info. .. note:: diff --git a/docs/topics/dynamic-content.rst b/docs/topics/dynamic-content.rst index 1c3607860..495111b56 100644 --- a/docs/topics/dynamic-content.rst +++ b/docs/topics/dynamic-content.rst @@ -104,6 +104,9 @@ If you get the expected response `sometimes`, but not always, the issue is probably not your request, but the target server. The target server might be buggy, overloaded, or :ref:`banning ` some of your requests. +Note that to translate a cURL command into a Scrapy request, +you may use `curl2scrapy `_. + .. _topics-handling-response-formats: Handling different response formats @@ -115,7 +118,7 @@ data from it depends on the type of response: - If the response is HTML or XML, use :ref:`selectors ` as usual. -- If the response is JSON, use `json.loads`_ to load the desired data from +- If the response is JSON, use :func:`json.loads` to load the desired data from :attr:`response.text `:: data = json.loads(response.text) @@ -130,8 +133,9 @@ data from it depends on the type of response: - If the response is JavaScript, or HTML with a ``