ImportError: dynamic module does not define init function (initfizzbuzz)

Question

I tried to compile fizzbuzz.c, in order to import it by python. For building fizzbuzz.c,I used python setup.py build_ext -i.

After building it, I tried to import fizzbuzz.c but the error below occurred. How can I solve this problem ?

Error

>>> import fizzbuzz
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: dynamic module does not define init function (initfizzbuzz)

fizzbuzz.c

#include <stdio.h>

void fizzbuzz(int n){

    for (int i=1; i <= n; i++){
        if (i % 3 == 0 && i % 5 ==0){
            printf("fizzbuzz %d \n", i);
        }
        else if (i % 3 == 0){
            printf("fizz %d \n", i);
        }
        else if(i % 5 == 0){
            printf("buzz %d \n", i);
        }
    }
}

setup.py

from distutils.core import setup, Extension
module = Extension('fizzbuzz', ['fizzbuzz.c'])
setup(
      name='fizzbuzz',
      version='1.0',
      ext_modules=[module],
)

Answer 1

The error also occurs, when using boost::python, if the module name is different to the compiled .so file name. For example:

hello.cpp

#include <boost/python/module.hpp>
#include <boost/python/def.hpp>
using namespace std;
using namespace boost::python;

int helloWorld(){
    cout << "Hello world!" << endl;
    return 0;
}

BOOST_PYTHON_MODULE(libhello) {
    def("hello_world", helloWorld);
}

compilation command:

g++ -fpic -shared -o libfoo.so -Wl,-soname,"libfoo.so" hello.cpp -I<path/to/python> -L/usr/local/lib  -lboost_python-py34

When including in python with import libfoo the following error occurs:

ImportError: dynamic module does not define init function (PyInit_libfoo)

This is because of "libhello" and "libfoo" do not match.