Skip to main content

Powerful and Pythonic XML processing library combining libxml2/libxslt with the ElementTree API.

Project description

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 or see our bug tracker at

In case you want to use the current in-development version of lxml, you can get it from the github repository at . 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 if you have an appropriate version of Cython installed.

3.5.0b1 (2015-09-18)

Features added

  • cleanup_namespaces() accepts a new argument keep_ns_prefixes that does not remove definitions of the provided prefix-namespace mapping from the tree.

  • cleanup_namespaces() accepts a new argument top_nsmap that moves definitions of the provided prefix-namespace mapping to the top of the tree.

  • LP#1490451: Element objects gained a cssselect() method as known from lxml.html. Patch by Simon Sapin.

  • API functions and methods behave and look more like Python functions, which allows introspection on them etc. One side effect to be aware of is that the functions now bind as methods when assigned to a class variable. A quick fix is to wrap them in staticmethod() (as for normal Python functions).

  • ISO-Schematron support gained an option error_finder that allows passing a filter function for picking validation errors from reports.

  • LP#1243600: Elements in lxml.html gained a classes property that provides a set-like interface to the class attribute. Original patch by masklinn.

  • LP#1341964: The soupparser now handles DOCTYPE declarations, comments and processing instructions outside of the root element. Patch by Olli Pottonen.

  • LP#1421512: The docinfo of a tree was made editable to allow setting and removing the public ID and system ID of the DOCTYPE. Patch by Olli Pottonen.

  • LP#1442427: More work-arounds for quirks and bugs in pypy and pypy3.

  • lxml.html.soupparser now uses BeautifulSoup version 4 instead of version 3 if available.

Bugs fixed

  • Memory errors that occur during tree adaptations (e.g. moving subtrees to foreign documents) could leave the tree in a crash prone state.

  • Calling process_children() in an XSLT extension element without an output_parent argument failed with a TypeError. Fix by Jens Tröger.

  • GH#162: Image data in HTML data URLs is considered safe and no longer removed by lxml.html.clean JavaScript cleaner.

  • GH#166: Static build could link libraries in wrong order.

  • GH#172: Rely a bit more on libxml2 for encoding detection rather than rolling our own in some cases. Patch by Olli Pottonen.

  • GH#159: Validity checks for names and string content were tightened to detect the use of illegal characters early. Patch by Olli Pottonen.

  • LP#1421921: Comments/PIs before the DOCTYPE declaration were not serialised. Patch by Olli Pottonen.

  • LP#659367: Some HTML DOCTYPE declarations were not serialised. Patch by Olli Pottonen.

  • LP#1238503: lxml.doctestcompare is now consistent with stdlib’s doctest in how it uses + and - to refer to unexpected and missing output.

  • Empty prefixes are explicitly rejected when a namespace mapping is used with ElementPath to avoid hiding bugs in user code.

  • Several problems with PyPy were fixed by switching to Cython 0.23.

Release history Release notifications | RSS feed

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

lxml-3.5.0b1.tar.gz (3.8 MB view hashes)

Uploaded source

Built Distributions (3.6 MB view hashes)

Uploaded 3 4 (3.6 MB view hashes)

Uploaded 3 3 (3.6 MB view hashes)

Uploaded 3 2 (3.6 MB view hashes)

Uploaded 2 7 (3.6 MB view hashes)

Uploaded 2 6

lxml-3.5.0b1.win32-py3.4.exe (3.3 MB view hashes)

Uploaded 3 4

lxml-3.5.0b1.win32-py3.3.exe (3.3 MB view hashes)

Uploaded 3 3

lxml-3.5.0b1.win32-py3.2.exe (3.3 MB view hashes)

Uploaded 3 2

lxml-3.5.0b1.win32-py2.7.exe (3.3 MB view hashes)

Uploaded 2 7

lxml-3.5.0b1.win32-py2.6.exe (3.3 MB view hashes)

Uploaded 2 6

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page