[setup.py with cython] #cython #python #python3 #setup #setup.py

cython-python-setup.py

# REFERENCE: https://stackoverflow.com/questions/4505747/how-should-i-structure-a-python-package-that-contains-cython-code 
# github) (I don't expect this to be a popular package, but it was a good chance to learn Cython).
# This method relies on the fact that building a .pyx file with Cython.Distutils.build_ext (at least with Cython version 0.14) always seems to create a .c file in the same directory as the source .pyx file.
# Here is a cut-down version of setup.py which I hope shows the essentials:

from distutils.core import setup
from distutils.extension import Extension

try:
    from Cython.Distutils import build_ext
except ImportError:
    use_cython = False
else:
    use_cython = True

cmdclass = { }
ext_modules = [ ]

if use_cython:
    ext_modules += [
        Extension("mypackage.mycythonmodule", [ "cython/mycythonmodule.pyx" ]),
    ]
    cmdclass.update({ 'build_ext': build_ext })
else:
    ext_modules += [
        Extension("mypackage.mycythonmodule", [ "cython/mycythonmodule.c" ]),
    ]

setup(
    name='mypackage',
    ...
    cmdclass = cmdclass,
    ext_modules=ext_modules,
    ...
)

# I also edited MANIFEST.in to ensure that mycythonmodule.c is included in a source distribution (a source distribution that is created with python setup.py sdist):

# ...
# recursive-include cython *
# ...
# I don't commit mycythonmodule.c to version control 'trunk' (or 'default' for Mercurial). When I make a release, I need to remember to do a python setup.py build_ext first, to ensure that mycythonmodule.c is present and up-to-date for the source code distribution. I also make a release branch, and commit the C file into the branch. That way I have a historical record of the C file that was distributed with that release.