html5lib is a pure-python library for parsing HTML. It is designed to conform to the WHATWG HTML specification, as is implemented by all major web browsers.

Simple usage follows this pattern:

importhtml5libwithopen("mydocument.html", "rb") asf: document=html5lib.parse(f)

or:

importhtml5libdocument=html5lib.parse("<p>Hello World!")

By default, the document will be an xml.etree element instance. Whenever possible, html5lib chooses the accelerated ElementTree implementation (i.e. xml.etree.cElementTree on Python 2.x).

Two other tree types are supported: xml.dom.minidom and lxml.etree. To use an alternative format, specify the name of a treebuilder:

importhtml5libwithopen("mydocument.html", "rb") asf: lxml_etree_document=html5lib.parse(f, treebuilder="lxml")

When using with urllib2 (Python 2), the charset from HTTP should be pass into html5lib as follows:

fromcontextlibimportclosingfromurllib2importurlopenimporthtml5libwithclosing(urlopen("http://example.com/")) asf: document=html5lib.parse(f, transport_encoding=f.info().getparam("charset"))

When using with urllib.request (Python 3), the charset from HTTP should be pass into html5lib as follows:

fromurllib.requestimporturlopenimporthtml5libwithurlopen("http://example.com/") asf: document=html5lib.parse(f, transport_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:

importhtml5libwithopen("mydocument.html", "rb") asf: parser=html5lib.HTMLParser(strict=True) document=parser.parse(f)

When you're instantiating parser objects explicitly, pass a treebuilder class as the tree keyword argument to use an alternative document format:

importhtml5libparser=html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom")) minidom_document=parser.parse("<p>Hello World!")

More documentation is available at https://html5lib.readthedocs.io/.

html5lib works on CPython 2.7+, CPython 3.5+ and PyPy. To install:

$ pip install html5lib

The goal is to support a (non-strict) superset of the versions that pip supports.

The following third-party libraries may be used for additional functionality:

• lxml is supported as a tree format (for both building and walking) under CPython (but not PyPy where it is known to cause segfaults);
• genshi has a treewalker (but not builder); and
• chardet can be used as a fallback when character encoding cannot be determined.

Please report any bugs on the issue tracker.

Unit tests require the pytest and mock libraries and can be run using the pytest command in the root directory.

Test data are contained in a separate html5lib-tests repository and included as 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 your system, you can run tests on all of them using the tox utility, which can be found on PyPI.

Check out the docs. Still need help? Go to our GitHub Discussions.

You can also browse the archives of the html5lib-discuss mailing list.