PYTHON setup.py build_ext --inplace
PYTHON -c "import a"

######## setup.py ########

from distutils.core import setup
from distutils.extension import Extension
from Cython.Distutils import build_ext

setup(
  cmdclass = {'build_ext': build_ext},
  ext_modules = [Extension("a", ["a.pyx"])],
)

######## a.pyx ########