该库旨在使解析 HTML(例如抓取网页)尽可能简单直观。
使用此库时,您会自动获得:
使用 Requests 向“python.org”发出 GET 请求:
>>> from requests_html import HTMLSession
>>> session = HTMLSession()
>>> r = session.get( ' https://python.org/ ' )
尝试异步并同时获取一些网站:
>>> from requests_html import AsyncHTMLSession
>>> asession = AsyncHTMLSession()
>>> async def get_pythonorg ():
... r = await asession.get( ' https://python.org/ ' )
... return r
...
>>> async def get_reddit ():
... r = await asession.get( ' https://reddit.com/ ' )
... return r
...
>>> async def get_google ():
... r = await asession.get( ' https://google.com/ ' )
... return r
...
>>> results = asession.run(get_pythonorg, get_reddit, get_google)
>>> results # check the requests all returned a 200 (success) code
[<Response [200]>, <Response [200]>, <Response [200]>]
>>> # Each item in the results list is a response object and can be interacted with as such
>>> for result in results:
... print (result.html.url)
...
https://www.python.org/
https://www.google.com/
https://www.reddit.com/
请注意,结果列表中对象的顺序表示它们返回的顺序,而不是协程传递给run
方法的顺序,示例中的顺序不同。
按原样获取页面上所有链接的列表(不包括锚点):
>>> r.html.links
{'//docs.python.org/3/tutorial/', '/about/apps/', 'https://github.com/python/pythondotorg/issues', '/accounts/login/', '/dev/peps/', '/about/legal/', '//docs.python.org/3/tutorial/introduction.html#lists', '/download/alternatives', 'http://feedproxy.google.com/~r/PythonInsider/~3/kihd2DW98YY/python-370a4-is-available-for-testing.html', '/download/other/', '/downloads/windows/', 'https://mail.python.org/mailman/listinfo/python-dev', '/doc/av', 'https://devguide.python.org/', '/about/success/#engineering', 'https://wiki.python.org/moin/PythonEventsCalendar#Submitting_an_Event', 'https://www.openstack.org', '/about/gettingstarted/', 'http://feedproxy.google.com/~r/PythonInsider/~3/AMoBel8b8Mc/python-3.html', '/success-stories/industrial-light-magic-runs-python/', 'http://docs.python.org/3/tutorial/introduction.html#using-python-as-a-calculator', '/', 'http://pyfound.blogspot.com/', '/events/python-events/past/', '/downloads/release/python-2714/', 'https://wiki.python.org/moin/PythonBooks', 'http://plus.google.com/+Python', 'https://wiki.python.org/moin/', 'https://status.python.org/', '/community/workshops/', '/community/lists/', 'http://buildbot.net/', '/community/awards', 'http://twitter.com/ThePSF', 'https://docs.python.org/3/license.html', '/psf/donations/', 'http://wiki.python.org/moin/Languages', '/dev/', '/events/python-user-group/', 'https://wiki.qt.io/PySide', '/community/sigs/', 'https://wiki.gnome.org/Projects/PyGObject', 'http://www.ansible.com', 'http://www.saltstack.com', 'http://planetpython.org/', '/events/python-events', '/about/help/', '/events/python-user-group/past/', '/about/success/', '/psf-landing/', '/about/apps', '/about/', 'http://www.wxpython.org/', '/events/python-user-group/665/', 'https://www.python.org/psf/codeofconduct/', '/dev/peps/peps.rss', '/downloads/source/', '/psf/sponsorship/sponsors/', 'http://bottlepy.org', 'http://roundup.sourceforge.net/', 'http://pandas.pydata.org/', 'http://brochure.getpython.info/', 'https://bugs.python.org/', '/community/merchandise/', 'http://tornadoweb.org', '/events/python-user-group/650/', 'http://flask.pocoo.org/', '/downloads/release/python-364/', '/events/python-user-group/660/', '/events/python-user-group/638/', '/psf/', '/doc/', 'http://blog.python.org', '/events/python-events/604/', '/about/success/#government', 'http://python.org/dev/peps/', 'https://docs.python.org', 'http://feedproxy.google.com/~r/PythonInsider/~3/zVC80sq9s00/python-364-is-now-available.html', '/users/membership/', '/about/success/#arts', 'https://wiki.python.org/moin/Python2orPython3', '/downloads/', '/jobs/', 'http://trac.edgewall.org/', 'http://feedproxy.google.com/~r/PythonInsider/~3/wh73_1A-N7Q/python-355rc1-and-python-348rc1-are-now.html', '/privacy/', 'https://pypi.python.org/', 'http://www.riverbankcomputing.co.uk/software/pyqt/intro', 'http://www.scipy.org', '/community/forums/', '/about/success/#scientific', '/about/success/#software-development', '/shell/', '/accounts/signup/', 'http://www.facebook.com/pythonlang?fref=ts', '/community/', 'https://kivy.org/', '/about/quotes/', 'http://www.web2py.com/', '/community/logos/', '/community/diversity/', '/events/calendars/', 'https://wiki.python.org/moin/BeginnersGuide', '/success-stories/', '/doc/essays/', '/dev/core-mentorship/', 'http://ipython.org', '/events/', '//docs.python.org/3/tutorial/controlflow.html', '/about/success/#education', '/blogs/', '/community/irc/', 'http://pycon.blogspot.com/', '//jobs.python.org', 'http://www.pylonsproject.org/', 'http://www.djangoproject.com/', '/downloads/mac-osx/', '/about/success/#business', 'http://feedproxy.google.com/~r/PythonInsider/~3/x_c9D0S-4C4/python-370b1-is-now-available-for.html', 'http://wiki.python.org/moin/TkInter', 'https://docs.python.org/faq/', '//docs.python.org/3/tutorial/controlflow.html#defining-functions'}
以绝对形式获取页面上所有链接的列表(不包括锚点):
>>> r.html.absolute_links
{'https://github.com/python/pythondotorg/issues', 'https://docs.python.org/3/tutorial/', 'https://www.python.org/about/success/', 'http://feedproxy.google.com/~r/PythonInsider/~3/kihd2DW98YY/python-370a4-is-available-for-testing.html', 'https://www.python.org/dev/peps/', 'https://mail.python.org/mailman/listinfo/python-dev', 'https://www.python.org/doc/', 'https://www.python.org/', 'https://www.python.org/about/', 'https://www.python.org/events/python-events/past/', 'https://devguide.python.org/', 'https://wiki.python.org/moin/PythonEventsCalendar#Submitting_an_Event', 'https://www.openstack.org', 'http://feedproxy.google.com/~r/PythonInsider/~3/AMoBel8b8Mc/python-3.html', 'https://docs.python.org/3/tutorial/introduction.html#lists', 'http://docs.python.org/3/tutorial/introduction.html#using-python-as-a-calculator', 'http://pyfound.blogspot.com/', 'https://wiki.python.org/moin/PythonBooks', 'http://plus.google.com/+Python', 'https://wiki.python.org/moin/', 'https://www.python.org/events/python-events', 'https://status.python.org/', 'https://www.python.org/about/apps', 'https://www.python.org/downloads/release/python-2714/', 'https://www.python.org/psf/donations/', 'http://buildbot.net/', 'http://twitter.com/ThePSF', 'https://docs.python.org/3/license.html', 'http://wiki.python.org/moin/Languages', 'https://docs.python.org/faq/', 'https://jobs.python.org', 'https://www.python.org/about/success/#software-development', 'https://www.python.org/about/success/#education', 'https://www.python.org/community/logos/', 'https://www.python.org/doc/av', 'https://wiki.qt.io/PySide', 'https://www.python.org/events/python-user-group/660/', 'https://wiki.gnome.org/Projects/PyGObject', 'http://www.ansible.com', 'http://www.saltstack.com', 'https://www.python.org/dev/peps/peps.rss', 'http://planetpython.org/', 'https://www.python.org/events/python-user-group/past/', 'https://docs.python.org/3/tutorial/controlflow.html#defining-functions', 'https://www.python.org/community/diversity/', 'https://docs.python.org/3/tutorial/controlflow.html', 'https://www.python.org/community/awards', 'https://www.python.org/events/python-user-group/638/', 'https://www.python.org/about/legal/', 'https://www.python.org/dev/', 'https://www.python.org/download/alternatives', 'https://www.python.org/downloads/', 'https://www.python.org/community/lists/', 'http://www.wxpython.org/', 'https://www.python.org/about/success/#government', 'https://www.python.org/psf/', 'https://www.python.org/psf/codeofconduct/', 'http://bottlepy.org', 'http://roundup.sourceforge.net/', 'http://pandas.pydata.org/', 'http://brochure.getpython.info/', 'https://www.python.org/downloads/source/', 'https://bugs.python.org/', 'https://www.python.org/downloads/mac-osx/', 'https://www.python.org/about/help/', 'http://tornadoweb.org', 'http://flask.pocoo.org/', 'https://www.python.org/users/membership/', 'http://blog.python.org', 'https://www.python.org/privacy/', 'https://www.python.org/about/gettingstarted/', 'http://python.org/dev/peps/', 'https://www.python.org/about/apps/', 'https://docs.python.org', 'https://www.python.org/success-stories/', 'https://www.python.org/community/forums/', 'http://feedproxy.google.com/~r/PythonInsider/~3/zVC80sq9s00/python-364-is-now-available.html', 'https://www.python.org/community/merchandise/', 'https://www.python.org/about/success/#arts', 'https://wiki.python.org/moin/Python2orPython3', 'http://trac.edgewall.org/', 'http://feedproxy.google.com/~r/PythonInsider/~3/wh73_1A-N7Q/python-355rc1-and-python-348rc1-are-now.html', 'https://pypi.python.org/', 'https://www.python.org/events/python-user-group/650/', 'http://www.riverbankcomputing.co.uk/software/pyqt/intro', 'https://www.python.org/about/quotes/', 'https://www.python.org/downloads/windows/', 'https://www.python.org/events/calendars/', 'http://www.scipy.org', 'https://www.python.org/community/workshops/', 'https://www.python.org/blogs/', 'https://www.python.org/accounts/signup/', 'https://www.python.org/events/', 'https://kivy.org/', 'http://www.facebook.com/pythonlang?fref=ts', 'http://www.web2py.com/', 'https://www.python.org/psf/sponsorship/sponsors/', 'https://www.python.org/community/', 'https://www.python.org/download/other/', 'https://www.python.org/psf-landing/', 'https://www.python.org/events/python-user-group/665/', 'https://wiki.python.org/moin/BeginnersGuide', 'https://www.python.org/accounts/login/', 'https://www.python.org/downloads/release/python-364/', 'https://www.python.org/dev/core-mentorship/', 'https://www.python.org/about/success/#business', 'https://www.python.org/community/sigs/', 'https://www.python.org/events/python-user-group/', 'http://ipython.org', 'https://www.python.org/shell/', 'https://www.python.org/community/irc/', 'https://www.python.org/about/success/#engineering', 'http://www.pylonsproject.org/', 'http://pycon.blogspot.com/', 'https://www.python.org/about/success/#scientific', 'https://www.python.org/doc/essays/', 'http://www.djangoproject.com/', 'https://www.python.org/success-stories/industrial-light-magic-runs-python/', 'http://feedproxy.google.com/~r/PythonInsider/~3/x_c9D0S-4C4/python-370b1-is-now-available-for.html', 'http://wiki.python.org/moin/TkInter', 'https://www.python.org/jobs/', 'https://www.python.org/events/python-events/604/'}
使用 CSS 选择器选择一个元素:
>>> about = r.html.find( ' #about ' , first = True )
获取元素的文本内容:
>>> print (about.text)
About
Applications
Quotes
Getting Started
Help
Python Brochure
内省元素的属性:
>>> about.attrs
{'id': 'about', 'class': ('tier-1', 'element-1'), 'aria-haspopup': 'true'}
渲染出元素的 HTML:
>>> about.html
'<li aria-haspopup="true" class="tier-1 element-1 " id="about">n<a class="" href="/about/" title="">About</a>n<ul aria-hidden="true" class="subnav menu" role="menu">n<li class="tier-2 element-1" role="treeitem"><a href="/about/apps/" title="">Applications</a></li>n<li class="tier-2 element-2" role="treeitem"><a href="/about/quotes/" title="">Quotes</a></li>n<li class="tier-2 element-3" role="treeitem"><a href="/about/gettingstarted/" title="">Getting Started</a></li>n<li class="tier-2 element-4" role="treeitem"><a href="/about/help/" title="">Help</a></li>n<li class="tier-2 element-5" role="treeitem"><a href="http://brochure.getpython.info/" title="">Python Brochure</a></li>n</ul>n</li>'
在元素中选择元素:
>>> about.find( ' a ' )
[<Element 'a' href='/about/' title='' class=''>, <Element 'a' href='/about/apps/' title=''>, <Element 'a' href='/about/quotes/' title=''>, <Element 'a' href='/about/gettingstarted/' title=''>, <Element 'a' href='/about/help/' title=''>, <Element 'a' href='http://brochure.getpython.info/' title=''>]
搜索元素内的链接:
>>> about.absolute_links
{'http://brochure.getpython.info/', 'https://www.python.org/about/gettingstarted/', 'https://www.python.org/about/', 'https://www.python.org/about/quotes/', 'https://www.python.org/about/help/', 'https://www.python.org/about/apps/'}
在页面上搜索文本:
>>> r.html.search( ' Python is a {} language ' )[ 0 ]
programming
更复杂的 CSS 选择器示例(从 Chrome 开发工具复制):
>>> r = session.get( ' https://github.com/ ' )
>>> sel = ' body > div.application-main > div.jumbotron.jumbotron-codelines > div > div > div.col-md-7.text-center.text-md-left > p '
>>> print (r.html.find(sel, first = True ).text)
GitHub is a development platform inspired by the way you work. From open source to business, you can host and review code, manage projects, and build software alongside millions of other developers.
还支持 XPath:
>>> r.html.xpath( ' /html/body/div[1]/a ' )
[<Element 'a' class=('px-2', 'py-4', 'show-on-focus', 'js-skip-to-content') href='#start-of-content' tabindex='1'>]
让我们获取一些由 JavaScript 呈现的文本。到 2020 年,Python 2.7 倒计时时钟(https://pythonclock.org)将作为一个很好的测试页面:
>>> r = session.get( ' https://pythonclock.org ' )
让我们尝试看看动态渲染的代码(倒计时时钟)。为了首先快速完成此操作,我们将在之前看到的最后一个文本(“Python 2.7 will退休...”)和之后看到的第一个文本(“启用 Guido 模式”)之间进行搜索。
>>> r.html.search( ' Python 2.7 will retire in... {} Enable Guido Mode ' )[ 0 ]
'</h1>n </div>n <div class="python-27-clock"></div>n <div class="center">n <div class="guido-button-block">n <button class="js-guido-mode guido-button">'
请注意,时钟不见了。 render()
方法获取响应并呈现动态内容,就像 Web 浏览器一样。
>>> r.html.render()
>>> r.html.search( ' Python 2.7 will retire in... {} Enable Guido Mode ' )[ 0 ]
'</h1>n </div>n <div class="python-27-clock is-countdown"><span class="countdown-row countdown-show6"><span class="countdown-section"><span class="countdown-amount">1</span><span class="countdown-period">Year</span></span><span class="countdown-section"><span class="countdown-amount">2</span><span class="countdown-period">Months</span></span><span class="countdown-section"><span class="countdown-amount">28</span><span class="countdown-period">Days</span></span><span class="countdown-section"><span class="countdown-amount">16</span><span class="countdown-period">Hours</span></span><span class="countdown-section"><span class="countdown-amount">52</span><span class="countdown-period">Minutes</span></span><span class="countdown-section"><span class="countdown-amount">46</span><span class="countdown-period">Seconds</span></span></span></div>n <div class="center">n <div class="guido-button-block">n <button class="js-guido-mode guido-button">'
让我们把它清理一下。这一步不是必需的,它只是使返回的 html 更容易可视化,以查看我们需要定位哪些内容来提取所需的信息。
>>> from pprint import pprint
>>> pprint(r.html.search('Python 2.7 will retire in...{}Enable')[0])
('</h1>n'
' </div>n'
' <div class="python-27-clock is-countdown"><span class="countdown-row '
'countdown-show6"><span class="countdown-section"><span '
'class="countdown-amount">1</span><span '
'class="countdown-period">Year</span></span><span '
'class="countdown-section"><span class="countdown-amount">2</span><span '
'class="countdown-period">Months</span></span><span '
'class="countdown-section"><span class="countdown-amount">28</span><span '
'class="countdown-period">Days</span></span><span '
'class="countdown-section"><span class="countdown-amount">16</span><span '
'class="countdown-period">Hours</span></span><span '
'class="countdown-section"><span class="countdown-amount">52</span><span '
'class="countdown-period">Minutes</span></span><span '
'class="countdown-section"><span class="countdown-amount">46</span><span '
'class="countdown-period">Seconds</span></span></span></div>n'
' <div class="center">n'
' <div class="guido-button-block">n'
' <button class="js-guido-mode guido-button">')
渲染的 html 具有与上面相同的方法和属性。让我们将我们想要的数据提取到易于在其他地方使用并像字典一样进行反思的东西。
>>> periods = [element.text for element in r.html.find( ' .countdown-period ' )]
>>> amounts = [element.text for element in r.html.find( ' .countdown-amount ' )]
>>> countdown_data = dict ( zip (periods, amounts))
>>> countdown_data
{'Year': '1', 'Months': '2', 'Days': '5', 'Hours': '23', 'Minutes': '34', 'Seconds': '37'}
或者您也可以执行此异步操作:
>>> async def get_pyclock ():
... r = await asession.get( ' https://pythonclock.org/ ' )
... await r.html.arender()
... return r
...
>>> results = asession.run(get_pyclock, get_pyclock, get_pyclock)
其余代码的操作方式与同步版本相同,只是results
是包含多个响应对象的列表,但是可以应用与上面相同的基本过程来提取所需的数据。
请注意,第一次运行render()
方法时,它会将 Chromium 下载到您的主目录(例如~/.pyppeteer/
)。这只会发生一次。
您也可以在没有请求的情况下使用该库:
>>> from requests_html import HTML
>>> doc = """ <a href='https://httpbin.org'> """
>>> html = HTML( html = doc)
>>> html.links
{'https://httpbin.org'}
$ pipenv install requests-html
?
仅支持Python 3.6及以上版本。