warning LNK4197: export 'PyInit_python_module_name' specified multiple times; using first specification

Question

I created some Cython files, and import them in a Python file using,

import pyximport
pyximport.install()

import Cython_Mod1
import Cython_Mod2

When I run the py file, the C compiler (VC++14) generated the following errors

Cython_Mod1.obj : warning LNK4197: export 'PyInit_Cython_Mod1' specified multiple times; using first specification

for each Cythonmodule.

How to fix this and does it affect the performance or can be erroneous in the execution.

Answer 1

LNK4197 is a warning, as such it shouldn't affect the compilation of your .c files, Cython probably just generates code that exports that function multiple times (for good reasons, I'd assume).

Since PyInit_<modname> is responsible for initializing the module; if your modules get initialized and imported correctly you have no issues. It won't affect the performance and/or result in erroneous execution.