Mailman 3 March 2018 - cython-devel

PEP draft to get rid of the "cyfunction" class
by Jeroen Demeyer March 31, 2018

March 31, 2018

I have drafted a PEP (not officially submitted yet) to unify built-in and Python functions. Cython could benefit from this because cyfunctions could finally be considered functions without sacrificing performance. You find the proposal at https://github.com/jdemeyer/PEP-functions For comments and discussion, please post on the python-ideas thread https://mail.python.org/pipermail/python-ideas/2018-March/049563.html Happy Easter, Jeroen.

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New organisation of the docs
by Gabriel de Marmiesse March 24, 2018

March 24, 2018

Hi! After some time spent on the docs, I noticed quite some duplicates, and also that sometime, going through many pages is needed to gather bits of information about a subject (eg. compilation, interacting with C code, extension types...). I propose to break the previous splitting tutorial / userguide in favor to a structure "by topic", which would allow us to: - spot documentation duplicates easily, - making navigation easier for the users - ultimately avoid the hassle of "I want to use learn Numpy with Cython, should I go to "Working with Numpy", "Typed memoryviews" or "Cython for Numpy users". Of course I would mean fusing some pages together and reorganizing some things inside the pages, creating new ones... But for the moment, I would like to just focus about sections names and what pages we put inside. It's a quick grouping, I'm looking for feedback, feel free to change it (especially the names): Getting Started: - Cython - an overview - Installing Cython - Installing MinGW on windows - Building Cython code - Faster code via static typing - Basic tutorial - Language basics (from users guide) - Language basics (from Reference Guide) Working with C: - calling C functions - Using C libraries - Interfacing with external C code - Unicode and passing strings - Memory allocation - Using C++ in Cython Language features: - Tutorial on extension types (aka. cdef classes). - Extension types (from Users guide) - Extension types (from Reference guide) - Special methods of extension types - pxd files - pure python mode - early bindings for speed - Fused types (Templates) - Porting Cython code to PyPy - Using parallelism - Pythran as a Numpy backend Things to watch out for: - caveats - limitations - differences between Cython and Pyrex Compilation: - Source files and compilation - Compilation - sharing declarations between Cython modules - profiling - Debugging your Cython program Interacting efficiently with python: - Working with Numpy - Working with Python arrays - Typed memoryviews - Implementing the buffer protocol - Cython for Numpy Users to be named: - Further reading - Related work Reference Guide: - Interfacing with Other Code - Special Mention - Limitations - Compiler Directives - Indices and tables Gabriel de Marmiesse

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Cython 0.28.1 released
by Stefan Behnel March 18, 2018

March 18, 2018

Hi all, thanks to your excellent bug reports, here is a bug fix release for the recent 0.28. https://pypi.python.org/pypi/Cython/0.28.1 Changelog: https://github.com/cython/cython/blob/0.28.1/CHANGES.rst Bugs fixed for this release: * ``PyFrozenSet_New()`` was accidentally used in PyPy where it is missing from the C-API. * Assignment between some C++ templated types were incorrectly rejected when the templates mix ``const`` with ``ctypedef``. (Github issue #2148) * Undeclared C++ no-args constructors in subclasses could make the compilation fail if the base class constructor was declared without ``nogil``. (Github issue #2157) * Bytes %-formatting inferred ``basestring`` (bytes or unicode) as result type in some cases where ``bytes`` would have been safe to infer. (Github issue #2153) * ``None`` was accidentally disallowed as typed return value of ``dict.pop()``. (Github issue #2152) Have fun, Stefan

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Workshop on interfacing (math) software with low level libraries
by Jeroen Demeyer March 15, 2018

March 15, 2018

Dear Cython developers, This is a reminder of ODK's workshop on "Interfacing (math) software with low-level libraries", April 30th-May 4th in Cernay near Paris: https://github.com/OpenDreamKit/OpenDreamKit/issues/251 Registrations have started (see the above web page). Details: (Math) Computational systems face a tension between using high level languages (e.g. Python) for expressivity, ease of use and prototyping, and low-level languages (e.g. C/C++) for power and speed, and also for modularity (using existing libraries, or writing reusable ones). To resolve this tension, many approaches have been explored in the recent years, and the frontier between the two worlds is becoming increasingly blurry. The purpose of this workshop is to bring together developers to share expertise, seek collaboration venues, and get into concrete action. This is quite bold. The focus on math software should keep this manageable, while providing a large enough variety of solutions and use cases. - Developers of "binding systems" such as cppyy, pybind11, Boost Python - Developers of "compilers" such as Cython, Pythran, Numba - Developers of interactive C++ environments (cling, xeus-cling, xtensor, ...) - Developers of (math) libraries in a low level language that wish to make their code accessible to a variety of users (e.g. libsemigroups, or low-level combinatorics HPCombi, number theory and arithmetic FLINT; in general developers of C-level interfaces to various systems: libSingular, libgap, cypari, cypari2, giacpy, PyNormaliz, Linbox, meataxe; - Developers of systems like GAP, SageMath, Oscar, Mathemagix, ROOT that make a heavy use of such technologies - Developers of programming languages like Julia - ... Organizers: - Vincent Delecroix, Serge Gelton, Florent Hivert, Nicolas Thiéry Funding: OpenDreamKit should be able to fund all the local expenses (as in previous workshops in Cernay), the travel expenses of ODK members, and the travel expenses of some invited people.

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Cython 0.28 beta 1 is available!
by Stefan Behnel March 13, 2018

March 13, 2018

Hi all, after almost half a year of development and a late couple of weeks of bug hunting and feature cleanup, I'm happy to announce the availability of the first beta of Cython 0.28. https://github.com/cython/cython/releases/tag/0.28b1 This is a rather big feature release, please give it some testing. I'll not even start listing the major improvements here, but it comes with some really long-requested language features and lots of new optimisations, so please take a look at the changelog: https://github.com/cython/cython/blob/0.28b1/CHANGES.rst Have fun, Stefan

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