How to create both a c extension and a pure python package

[Michał Jaworski]

I was dealing with a very similar problem a long time ago. I wanted to
provide built wheels of my Cython extension for various OSes (Windows,
macOS, Linux) and various Python versions (from 2.7 up to 3.9) but I also
wanted to have a sdist package for all the variations that I didn't cover
at the time.

What I ended up doing was automating the whole process on two different CI
systems (one of those didn't have Windows support and the other was
Windows-only) but also provided the sdist distribution with both Cython and
Cython-generated C++ sources. Users can opt-in for cython installation
using setuptools extras feature. For instance:

pip install my-package[with-cython]

Additionally whether to compile from Cython or C++ sources is controlled
with environment variable, something like:

CYTHONIZE=1 pip install my-package

Using env vars instead of extra command arg for setup.py makes it easy to
use with pip, poetry or whatever installer your user decides to use.

The whole setup required a bit of work but in the end it has been working
for a few years already. Definitely the hardest thing to maintain are those
ever-changing CI systems. Adding the support for optional building from
sources was actually the simplest to do. I don't spend a lot of time on the
project lately but if you are interested how the whole thing was here's the
url: https://github.com/swistakm/pyimgui


śr., 10 mar 2021 o 20:57 Mats Wichmann <mats at wichmann.us> napisał(a):

> On 3/10/21 11:56 AM, Thomas Jollans wrote:
> > On 10/03/2021 18:42, Marco Sulla wrote:
> >> On Wed, 10 Mar 2021 at 16:45, Thomas Jollans <tjol at tjol.eu> wrote:
> >>> Why are you doing this?
> >>>
> >>> If all you want is for it to be possible to install the package from
> >>> source on a system that can't use the C part, you could just declare
> >>> your extension modules optional
> >> Because I want to provide (at least) two wheels: a wheel for linux
> >> users with the C extension compiled and a generic wheel in pure python
> >> as a fallback for any other architecture.
> >
> > What's wrong with sdist as a fallback rather than a wheel?
> >
> > That has the added benefit of people on other architectures have the
> > opportunity to use the extension module if they have a compiler and the
> > necessary libraries and headers installed...
>
> Doesn't that mean nasty failures for those don't have the correct build
> setup (like almost every Windows user on the planet)?   This isn't a
> snide question, I'm actually interested in solving roughly the same
> problem as the OP.
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>