I have  a small helper function test containing sensitive code. To mask this code, I have written the function in hello.pyx and using it in my package mypackage. 
I am able to build and use it by modifying the setup.py for the package to something like below:
import os                                                                                                                                             
from setuptools import setup, find_packages                                                                                                           
from Cython.Build import cythonize                                                                                                                    
os.chdir(os.path.normpath(os.path.join(os.path.abspath(__file__), os.pardir)))                                                                        
setup(                                                                                                                                                
    name='mypackage',                                                                                                                                  
    ext_modules = cythonize('mypackage/hello.pyx'),                                                                                             
    packages=find_packages(),                                                                                                                         
    include_package_data=True,                                                                                                                        
    )
However, when i build/install it via python setup.py or pip install, the cython generated hello.c as well as hello.so are getting placed in the install directory (in my case ~/.local/python2.7/site-packages/mypackage/)
I can manually remove the hello.c from the install directory (leaving just the hello.so file) and the package runs fine. 
Is there a way I can automate this process so that i don't need to manually remove the compiled c file ?
I looked at this stackoverflow question. However, I am getting an error during cythonize operation when i am trying to build the wheel using pip wheel . . Also, in my case I am fine with installing using tar.gz as long as the installed code doesn't contain plain text files for hello.c
[Edit]
I was able to stop placing a .c file in the install directory by using include_package_data=False in my setup.py.. However, am not exactly sure whether this option means for non python files in the project