setup.py

from setuptools import setup
from Cython.Build import cythonize
from setuptools.extension import Extension
import sys
import os

here = os.path.abspath(os.path.dirname(__file__))

extensions = []

# By default, don't build the ESP C++ extension on Windows
if '--esp_gen' in sys.argv or sys.platform != 'win32':

    # Generate with cython always (to keep up with cython versions)
    extensions.append(Extension(
        'esp_gen',
        ['cgbind/ext/esp_gen.pyx'],
        include_dirs=["cgbind/ext"])
    )

if '--esp_gen' in sys.argv:
    sys.argv.remove('--esp_gen')

setup(name='cgbind',
      version='1.0.4',
      description='Metallocage construction and binding affinity calculations',
      packages=['cgbind', 'cgbind.ext'],
      package_data={
          '': ['lib/*'],
          "cgbind.ext": ["esp_gen.pyx"]
      },
      ext_modules=cythonize(extensions, language_level="3", annotate=True),
      url='https://github.com/duartegroup/cgbind',
      license='MIT',
      author='cgbind developers',
      install_requires=['Cython'],
      setup_requires=['Cython'],
      python_requires=">3.7")