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:
import html5lib with open("mydocument.html", "rb") as f: document = html5lib.parse(f)
import html5lib document = html5lib.parse("<p>Hello World!")
By default, the
document will be an
xml.etree element instance.
Whenever possible, html5lib chooses the accelerated
xml.etree.cElementTree on Python 2.x).
Two other tree types are supported:
lxml.etree. To use an alternative format, specify the name of
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 be
pass 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, transport_encoding=f.info().getparam("charset"))
When using with
urllib.request (Python 3), the charset from HTTP
should be pass into html5lib as follows:
from urllib.request import urlopen import html5lib with urlopen("http://example.com/") as f: 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:
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 treebuilder
class as the
tree keyword argument to use an alternative document
import html5lib parser = 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:
lxmlis supported as a tree format (for both building and walking) under CPython (but not PyPy where it is known to cause segfaults);
genshihas a treewalker (but not builder); and
chardetcan be used as a fallback when character encoding cannot be determined.
Unit tests require the
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
which can be found on PyPI.
You can also browse the archives of the html5lib-discuss mailing list.