**************************** What's New In Python 3.4 **************************** .. :Author: Someone (uncomment if there is a principal author) .. Rules for maintenance: * Anyone can add text to this document, but the maintainer reserves the right to rewrite any additions. In particular, for obscure or esoteric features, the maintainer may reduce any addition to a simple reference to the new documentation rather than explaining the feature inline. * While the maintainer will periodically go through Misc/NEWS and add changes, it's best not to rely on this. We know from experience that any changes that aren't in the What's New documentation around the time of the original release will remain largely unknown to the community for years, even if they're added later. We also know from experience that other priorities can arise, and the maintainer will run out of time to do updates - in such cases, end users will be much better served by partial notifications that at least give a hint about new features to investigate. * This is not a complete list of every single change; completeness is the purpose of Misc/NEWS. The What's New should focus on changes that are visible to Python *users* and that *require* a feature release (i.e. most bug fixes should only be recorded in Misc/NEWS) * PEPs should not be marked Final until they have an entry in What's New. A placeholder entry that is just a section header and a link to the PEP (e.g ":pep:`397` has been implemented") is acceptable. If a PEP has been implemented and noted in What's New, don't forget to mark it as Final! * If you want to draw your new text to the attention of the maintainer, add 'XXX' to the beginning of the paragraph or section. * It's OK to add just a very brief note about a change. For example: "The :ref:`~socket.transmogrify()` function was added to the :mod:`socket` module." The maintainer will research the change and write the necessary text (if appropriate). The advantage of doing this is that even if no more descriptive text is ever added, readers will at least have a notification that the new feature exists and a link to the relevant documentation. * You can comment out your additions if you like, but it's not necessary (especially when a final release is some months away). * Credit the author of a patch or bugfix. Just the name is sufficient; the e-mail address isn't necessary. * It's helpful to add the bug/patch number as a comment: The :ref:`~socket.transmogrify()` function was added to the :mod:`socket` module. (Contributed by P.Y. Developer in :issue:`12345`.) This saves the maintainer the effort of going through the Mercurial log when researching a change. * Cross referencing tip: :ref:`mod.attr` will display as ``mod.attr``, while :ref:`~mod.attr` will display as ``attr``. This article explains the new features in Python 3.4, compared to 3.3. .. Python 3.4 was released on TBD. For full details, see the `changelog `_. .. note:: Prerelease users should be aware that this document is currently in draft form. It will be updated substantially as Python 3.4 moves towards release, so it's worth checking back even after reading earlier versions. .. seealso:: .. :pep:`4XX` - Python 3.4 Release Schedule Summary -- Release highlights ============================= .. This section singles out the most important changes in Python 3.4. Brevity is key. New syntax features: * None yet. New library modules: * None yet. New built-in features: * None yet. Implementation improvements: * A more efficient :mod:`marshal` format . Significantly Improved Library Modules: * SHA-3 (Keccak) support for :mod:`hashlib`. * TLSv1.1 and TLSv1.2 support for :mod:`ssl`. Security improvements: * None yet. Please read on for a comprehensive list of user-facing changes. .. PEP-sized items next. .. _pep-4XX: .. PEP 4XX: Example PEP .. ==================== .. (Implemented by Foo Bar.) .. .. seealso:: :pep:`4XX` - Example PEP PEP written by Example Author Other Language Changes ====================== Some smaller changes made to the core Python language are: * Unicode database updated to UCD version 6.2. New Modules =========== .. module name .. ----------- * None yet. Improved Modules ================ doctest ------- Added ``FAIL_FAST`` flag to halt test running as soon as the first failure is detected. (Contributed by R. David Murray and Daniel Urban in :issue:`16522`.) Optimizations ============= Major performance enhancements have been added: * The UTF-32 decoder is now 3x to 4x faster. Build and C API Changes ======================= Changes to Python's build process and to the C API include: * None yet. Deprecated ========== Unsupported Operating Systems ----------------------------- * None yet. Deprecated Python modules, functions and methods ------------------------------------------------ * :meth:`difflib.SequenceMatcher.isbjunk` and :meth:`difflib.SequenceMatcher.isbpopulur`: use ``x in sm.bjunk`` and ``x in sm.bpopular``, where sm is a :class:`~difflib.SequenceMatcher` object. Deprecated functions and types of the C API ------------------------------------------- * None yet. Deprecated features ------------------- * None yet. Porting to Python 3.4 ===================== This section lists previously described changes and other bugfixes that may require changes to your code. * Nothing yet.