[Cython] Cython 0.23 released

Stefan Behnel stefan_ml at behnel.de
Sat Aug 8 20:47:48 CEST 2015


Hi everyone,

given the positive feedback on the previous beta releases, I'm happy to
announce the final release of Cython 0.23. There were only minor changes
and fixes since the second beta.

https://pypi.python.org/pypi/Cython/0.23

This is a major feature release. Highlights include, in addition to several
important bug fixes:

  * PEP 492 (async/await) and PEP 448 (star-unpacking generalizations)
  * inlined generator expressions
  * support for the C++ assignment and bool() operators
  * support for coverage analysis

Complete changelog follows below. Upgrading is generally recommended.


You can get the signed release from here:

http://cython.org/

http://cython.org/release/Cython-0.23.tar.gz

http://cython.org/release/Cython-0.23.zip


SHA1 sums:
5a49123b39d89a20fb88bdc7886210c39cdff695  Cython-0.23.tar.gz
9bec6c6df861be49ed608a0ab688b67bba543abe  Cython-0.23.zip

Have fun,

Stefan



0.23 (2015-08-08)
=================

Features added
--------------

* PEP 492 (async/await) was implemented.
  See https://www.python.org/dev/peps/pep-0492/

* PEP 448 (Additional Unpacking Generalizations) was implemented.
  See https://www.python.org/dev/peps/pep-0448/

* Support for coverage.py 4.0+ can be enabled by adding the plugin
  "Cython.Coverage" to the ".coveragerc" config file.

* Annotated HTML source pages can integrate (XML) coverage reports.

* Tracing is supported in ``nogil`` functions/sections and module init
  code.

* When generators are used in a Cython module and the module imports the
  modules "inspect" and/or "asyncio", Cython enables interoperability by
  patching these modules during the import to recognise Cython's internal
  generator and coroutine types. This can be disabled by C compiling the
  module with "-D CYTHON_PATCH_ASYNCIO=0" or "-D CYTHON_PATCH_INSPECT=0"

* When generators or coroutines are used in a Cython module, their types
  are registered with the ``Generator`` and ``Coroutine`` ABCs in the
  ``collections`` or ``collections.abc`` stdlib module at import time to
  enable interoperability with code that needs to detect and process Python
  generators/coroutines.  These ABCs were added in CPython 3.5 and are
  available for older Python versions through the ``backports_abc`` module
  on PyPI.  See https://bugs.python.org/issue24018

* Adding/subtracting/dividing/modulus and equality comparisons with
  constant Python floats and small integers are faster.

* Binary and/or/xor/rshift operations with small constant Python integers
  are faster.

* When called on generator expressions, the builtins ``all()``, ``any()``,
  ``dict()``, ``list()``, ``set()``, ``sorted()`` and ``unicode.join()``
  avoid the generator iteration overhead by inlining a part of their
  functionality into the for-loop.

* Keyword argument dicts are no longer copied on function entry when they
  are not being used or only passed through to other function calls (e.g.
  in wrapper functions).

* The ``PyTypeObject`` declaration in ``cpython.object`` was extended.

* The builtin ``type`` type is now declared as PyTypeObject in source,
  allowing for extern functions taking type parameters to have the correct
  C signatures.  Note that this might break code that uses ``type`` just
  for passing around Python types in typed variables.  Removing the type
  declaration provides a backwards compatible fix.

* ``wraparound()`` and ``boundscheck()`` are available as no-ops in pure
  Python mode.

* Const iterators were added to the provided C++ STL declarations.

* Smart pointers were added to the provided C++ STL declarations.
  Patch by Daniel Filonik.

* ``NULL`` is allowed as default argument when embedding signatures.
  This fixes ticket 843.

* When compiling with ``--embed``, the internal module name is changed to
  ``__main__`` to allow arbitrary program names, including those that would
  be invalid for modules.  Note that this prevents reuse of the generated
  C code as an importable module.

* External C++ classes that overload the assignment operator can be used.
  Patch by Ian Henriksen.

* Support operator bool() for C++ classes so they can be used in
  if-statements.

Bugs fixed
----------

* Calling "yield from" from Python on a Cython generator that returned a
  value triggered a crash in CPython.  This is now being worked around.
  See https://bugs.python.org/issue23996

* Language level 3 did not enable true division (a.k.a. float division)
  for integer operands.

* Functions with fused argument types that included a generic 'object'
  fallback could end up using that fallback also for other explicitly
  listed object types.

* Relative cimports could accidentally fall back to trying an absolute
  cimport on failure.

* The result of calling a C struct constructor no longer requires an
  intermediate assignment when coercing to a Python dict.

* C++ exception declarations with mapping functions could fail to compile
  when pre-declared in .pxd files.

* ``cpdef void`` methods are now permitted.

* ``abs(cint)`` could fail to compile in MSVC and used sub-optimal code
  in C++.  Patch by David Vierra, original patch by Michael Enßlin.

* Buffer index calculations using index variables with small C integer
  types could overflow for large buffer sizes.
  Original patch by David Vierra.

* C unions use a saner way to coerce from and to Python dicts.

* When compiling a module ``foo.pyx``, the directories in ``sys.path``
  are no longer searched when looking for ``foo.pxd``.
  Patch by Jeroen Demeyer.

* Memory leaks in the embedding main function were fixed.
  Original patch by Michael Enßlin.

* Some complex Python expressions could fail to compile inside of finally
  clauses.

* Unprefixed 'str' literals were not supported as C varargs arguments.

* Fixed type errors in conversion enum types to/from Python.  Note that
  this imposes stricter correctness requirements on enum declarations.

Other changes
-------------

* Changed mangling scheme in header files generated by ``cdef api``
  declarations.

* Installation under CPython 3.3+ no longer requires a pass of the
  2to3 tool.  This also makes it possible to run Cython in Python
  3.3+ from a source checkout without installing it first.
  Patch by Petr Viktorin.

* ``jedi-typer.py`` (in ``Tools/``) was extended and renamed to
  ``jedityper.py`` (to make it importable) and now works with and
  requires Jedi 0.9.  Patch by Tzer-jen Wei.


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