# Python-Markdown 2.3 Release Notes

We are pleased to release Python-Markdown 2.3 which adds one new extension, removes a few old (obsolete) extensions, and now runs on both Python 2 and Python 3 without running the 2to3 conversion tool. See the list of changes below for details.

Python-Markdown supports Python versions 2.6, 2.7, 3.1, 3.2, and 3.3.

## Backwards-incompatible Changes

- Support has been dropped for Python 2.5. No guarantees are made that the library will work in any version of Python lower than 2.6. As all supported Python versions include the ElementTree library, Python-Markdown will no longer try to import a third-party installation of ElementTree.

- All classes are now “new-style” classes. In other words, all classes subclass from ‘object’. While this is not likely to affect most users, extension authors may need to make a few minor adjustments to their code.

- “safe_mode” has been further restricted. Markdown formatted links must be of a known white-listed scheme when in “safe_mode” or the URL is discarded. The white-listed schemes are: ‘HTTP’, ‘HTTPS’, ‘FTP’, ‘FTPS’, ‘MAILTO’, and ‘news’. Schemeless URLs are also permitted, but are checked in other ways - as they have been for some time.

- The ids assigned to footnotes now contain a dash (`-`) rather than a colon (`:`) when `output_format` it set to `"html5"` or `"xhtml5"`. If you are making reference to those ids in your JavaScript or CSS and using the HTML5 output, you will need to update your code accordingly. No changes are necessary if you are outputting XHTML (the default) or HTML4.

- The `force_linenos` configuration setting of the CodeHilite extension has been marked as Pending Deprecation and a new setting `linenums` has been added to replace it. See documentation for the CodeHilite Extension for an explanation of the new `linenums` setting. The new setting will honor the old `force_linenos` if it is set, but it will raise a `PendingDeprecationWarning` and will likely be removed in a future version of Python-Markdown.

- The “RSS” extension has been removed and no longer ships with Python-Markdown. If you would like to continue using the extension (not recommended), it is archived on GitHub.

- The “HTML Tidy” Extension has been removed and no longer ships with Python-Markdown. If you would like to continue using the extension (not recommended), it is archived on GitHub. Note that the underlying library, uTidylib, is not Python 3 compatible. Instead, it is recommended that the newer PyTidyLib (version 0.2.2+ for Python 3 comparability - install from GitHub not PyPI) be used. As the API for that library is rather simple, it is recommended that the output of Markdown be wrapped in a call to PyTidyLib rather than using an extension (for example: `tidylib.tidy_fragment(markdown.markdown(source), options={...})`).

## What’s New in Python-Markdown 2.3

- The entire code base now universally runs in Python 2 and Python 3 without any need for running the 2to3 conversion tool. This not only simplifies testing, but by using Unicode_literals, results in more consistent behavior across Python versions. Additionally, the relative imports (made possible in Python 2 via absolute_import) allows the entire library to more easily be embedded in a sub-directory of another project. The various files within the library will still import each other properly even though ‘markdown’ may not be in Python’s root namespace.

- The Admonition Extension has been added, which implements rST-style admonitions in the Markdown syntax. However, be warned that this extension is experimental and the syntax and behavior is still subject to change. Please try it out and report bugs and/or improvements.

- Various bug fixes have been made. See the commit log for a complete history of the changes.