cython setup.py file to compile packages

setup.py

# -*- coding: utf-8 -*-
#source: https://github.com/cython/cython/wiki/PackageHierarchy
'''
gd/
  __init__.py
  hello.pxd
  hello.pyx
  greetings/
    __init__.py
    en.pxd
    en.pyx
'''

import sys, os
from distutils.core import setup, Extension
from Cython.Distutils import build_ext


package_name = 'gd'
package_dir = 'gd'
packages = ['gd', 'gd.greetings']
compile_args = ['-Wall']
link_args = ['-g']


def scandir(dir, files=[]):
  for file in os.listdir(dir):
    path = os.path.join(dir, file)
    if os.path.isfile(path) and path.endswith('.pyx'):
      files.append(path.replace(os.path.sep, '.')[:-4])
    elif os.path.isdir(path):
      scandir(path, files)
  return files


def make_extension(extName):
  extPath = extName.replace('.', os.path.sep) + '.pyx'
  options = {
    'extra_compile_args': compile_args,
    'extra_link_args': link_args
  }
  return Extension(extName, [extPath], **options)


ext_names = scandir('gd')
extensions = [make_extension(name) for name in ext_names]
options = {
  'name': package_name,
  'packages': packages,
  'ext_modules': extensions,
  'cmdclass':  {'build_ext': build_ext}
}
setup(**options)