<filename>cython/hello_world/setup.py
from distutils.core import setup
from Cython.Build import cythonize

#  python setup.py build_ext --inplace

setup(
    ext_modules=cythonize('greeter.pyx')
)

<filename>cython/hello_world/setup.py
from distutils.core import setup
from Cython.Build import cythonize

#  python setup.py build_ext --inplace

setup(
    ext_modules=cythonize('greeter.pyx')
)

#  python setup.py build_ext --inplace