html5lib-modern 1.2

HTML parser based on the WHATWG HTML specification

html5lib

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.

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 an xml.etree element instance. Whenever possible, html5lib chooses the accelerated ElementTree implementation.

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

import html5lib
with open("mydocument.html", "rb") as f:
    lxml_etree_document = html5lib.parse(f, treebuilder="lxml")

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 format:

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/.

Installation

html5lib works on CPython 3.8+ and PyPy. To install:

$ pip install html5lib

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

Optional Dependencies

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.

Bugs

Please report any bugs on the issue tracker.

Tests

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.

Questions?

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

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

Credits

html5lib is written and maintained by:

• James Graham

• Sam Sneddon

• Łukasz Langa

• Will Kahn-Greene

Patches and suggestions

(In chronological order, by first commit:)

• Anne van Kesteren

• Lachlan Hunt

• lantis63

• Sam Ruby

• Thomas Broyer

• Tim Fletcher

• Mark Pilgrim

• Ryan King

• Philip Taylor

• Edward Z. Yang

• fantasai

• Philip Jägenstedt

• Ms2ger

• Mohammad Taha Jahangir

• Andy Wingo

• Andreas Madsack

• Karim Valiev

• Juan Carlos Garcia Segovia

• Mike West

• Marc DM

• Simon Sapin

• Michael[tm] Smith

• Ritwik Gupta

• Marc Abramowitz

• Tony Lopes

• lilbludevil

• Kevin

• Drew Hubl

• Austin Kumbera

• Jim Baker

• Jon Dufresne

• Donald Stufft

• Alex Gaynor

• Nik Nyby

• Jakub Wilk

• Sigmund Cherem

• Gabi Davar

• Florian Mounier

• neumond

• Vitalik Verhovodov

• Kovid Goyal

• Adam Chainz

• John Vandenberg

• Eric Amorde

• Benedikt Morbach

• Jonathan Vanasco

• Tom Most

• Ville Skyttä

• Hugo van Kemenade

• Mark Vasilkov

HTML5Lib-modern

• Ashley Sommer