http://html5lib.readthedocs.org/en/latest/
By default, the document will be an
xml.etree element instance.Whenever possible, html5lib chooses the accelerated
ElementTreeimplementation (i.e.
xml.etree.cElementTree on Python 2.x).
Overview
html5lib is a pure-python library for parsing HTML. It is designed toconform to the WHATWG HTML specification, as is implemented by all majorweb browsers.
Usage
Simple usage follows this pattern:
import html5lib
with open("mydocument.html", "rb") as f:
document = html5lib.parse(f)
or:
import html5lib
document = html5lib.parse("<p>Hello World!")
By default, the document will be anxml.etree element instance.Whenever possible, html5lib chooses the acceleratedElementTreeimplementation (i.e.xml.etree.cElementTree on Python 2.x).
Two other tree types are supported: xml.dom.minidom andlxml.etree. To use an alternative format, specify the name ofa treebuilder:
import html5lib
with open("mydocument.html", "rb") as f:
lxml_etree_document = html5lib.parse(f, treebuilder="lxml")
When using with urllib2 (Python 2), the charset from HTTP should bepass into html5lib as follows:
from contextlib import closing
from urllib2 import urlopen
import html5lib
with closing(urlopen("http://example.com/")) as f:
document = html5lib.parse(f, encoding=f.info().getparam("charset"))
When using with urllib.request (Python 3), the charset from HTTPshould be pass into html5lib as follows:
from urllib.request import urlopen
import html5lib
with urlopen("http://example.com/") as f:
document = html5lib.parse(f, encoding=f.info().get_content_charset())
To have more control over the parser, create a parser object explicitly.For instance, to make the parser raise exceptions on parse errors, use:
import html5lib
with open("mydocument.html", "rb") as f:
parser = html5lib.HTMLParser(strict=True)
document = parser.parse(f)
When you’re instantiating parser objects explicitly, pass a treebuilderclass as thetree keyword argument to use an alternative documentformat:
import html5lib
parser = html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom"))
minidom_document = parser.parse("<p>Hello World!")
More documentation is available at http://html5lib.readthedocs.org/.
Installation
html5lib works on CPython 2.6+, CPython 3.2+ and PyPy. To install it,use:
$ pip install html5lib
Optional Dependencies
The following third-party libraries may be used for additionalfunctionality:
- datrie can be used to improve parsing performance (though inalmost all cases the improvement is marginal);
- lxml is supported as a tree format (for both building andwalking) under CPython (butnot PyPy where it is known to causesegfaults);
- genshi has a treewalker (but not builder); and
- charade can be used as a fallback when character encoding cannotbe determined;chardet, from which it was forked, can also be usedon Python 2.
- ordereddict can be used under Python 2.6(collections.OrderedDict is used instead on later versions) toserialize attributes in alphabetical order.
Bugs
Please report any bugs on the issue tracker.
Tests
Unit tests require the nose library and can be run using thenosetests command in the root directory;ordereddict isrequired under Python 2.6. All should pass.
Test data are contained in a separate html5lib-tests repository and includedas a submodule, thus for git checkouts they must be initialized:
$ git submodule init
$ git submodule update
If you have all compatible Python implementations available on yoursystem, you can run tests on all of them using thetox utility,which can be found on PyPI.
Questions?
There’s a mailing list available for support on Google Groups,html5lib-discuss,though you may get a quicker response asking on IRC in#whatwg onirc.freenode.net.