lxml is a Pythonic, mature binding for the libxml2 and libxslt libraries. It provides safe and convenient access to these libraries using the ElementTree API.

It extends the ElementTree API significantly to offer support for XPath, RelaxNG, XML Schema, XSLT, C14N and much more.

To contact the project, go to the project home page <https://lxml.de/>_ or see our bug tracker at https://launchpad.net/lxml

In case you want to use the current in-development version of lxml, you can get it from the github repository at https://github.com/lxml/lxml . Note that this requires Cython to build the sources, see the build instructions on the project home page. To the same end, running easy_install lxml==dev will install lxml from https://github.com/lxml/lxml/tarball/master#egg=lxml-dev if you have an appropriate version of Cython installed.

After an official release of a new stable series, bug fixes may become available at https://github.com/lxml/lxml/tree/lxml-5.0 . Running easy_install lxml==5.0bugfix will install the unreleased branch state from https://github.com/lxml/lxml/tarball/lxml-5.0#egg=lxml-5.0bugfix as soon as a maintenance branch has been established. Note that this requires Cython to be installed at an appropriate version for the build.

5.0.0 (2023-12-29)

Features added

• Character escaping in C14N2 serialisation now uses a single pass over the text instead of searching for each unescaped character separately.

• Early support for Python 3.13a2 was added.

Bugs fixed

• LP#1976304: The Element.addnext() method previously inserted the new element before existing tail text. The tail text of both sibling elements now stays on the respective elements.

• LP#1980767, GH#379: TreeBuilder.close() could fail with a TypeError after parsing incorrect input. Original patch by Enrico Minack.

• Element.itertext(with_tail=False) returned the tail text of comments and processing instructions, despite the explicit option.

• GH#370: A crash with recent libxml2 2.11.x versions was resolved. Patch by Michael Schlenker.

• A compile problem with recent libxml2 2.12.x versions was resolved.

• The internal exception handling in C callbacks was improved for Cython 3.0.

• The exception declarations of xmlInputReadCallback, xmlInputCloseCallback, xmlOutputWriteCallback and xmlOutputCloseCallback in tree.pxd were corrected to prevent running Python code or calling into the C-API with a live exception set.

• GH#385: The long deprecated unittest.m̀akeSuite() function is no longer used. Patch by Miro Hrončok.

• LP#1522052: A file-system specific test is now optional and should no longer fail on systems that don't support it.

• GH#392: Some tests were adapted for libxml2 2.13. Patch by Nick Wellnhofer.

• Contains all fixes from lxml 4.9.4.

Other changes

• LP#1742885: lxml no longer expands external entities (XXE) by default to prevent the security risk of loading arbitrary files and URLs. If this feature is needed, it can be enabled in a backwards compatible way by using a parser with the option resolve_entities=True. The new default is resolve_entities='internal'.

• With libxml2 2.10.4 and later (as provided by the lxml 5.0 binary wheels), parsing HTML tags with "prefixes" no longer builds a namespace dictionary in nsmap but considers the prefix:name string the actual tag name. With older libxml2 versions, since 2.9.11, the prefix was removed. Before that, the prefix was parsed as XML prefix.

  lxml 5.0 does not try to hide this difference but now changes the ElementPath implementation to let element.find("part1:part2") search for the tag part1:part2 in documents parsed as HTML, instead of looking only for part2.

• LP#2024343: The validation of the schema file itself is now optional in the ISO-Schematron implementation. This was done because some lxml distributions discard the RNG validation schema file due to licensing issues. The validation can now always be disabled with Schematron(..., validate_schema=False). It is enabled by default if available and disabled otherwise. The module constant lxml.isoschematron.schematron_schema_valid_supported can be used to detect whether schema file validation is available.

• Some redundant and long deprecated methods were removed: parser.setElementClassLookup(), xslt_transform.apply(), xpath.evaluate().

• Some incorrect declarations were removed from python.pxd. In general, this file should not be used by external Cython code. Use the C-API declarations provided by Cython itself instead.

• Binary wheels use the library versions libxml2 2.12.3 and libxslt 1.1.39.

• Built with Cython 3.0.7, updated to follow recent changes in Cython 3.1-dev.