Overview — html5lib 1.2-dev documentation (original) (raw)

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("

Hello World!")

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).

Two other tree types are supported: xml.dom.minidom andlxml.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 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 format:

import html5lib parser = html5lib.HTMLParser(tree=html5lib.getTreeBuilder("dom")) minidom_document = parser.parse("

Hello World!")

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

Installation

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

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:

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.