Call Python function from C/C++ - c++

Question

I am trying to call a simple python function which is defined in ("ctest.py") as
def square(a)
return a**2
the following ("pytest.c") (in same directory) is the C code that I am trying to use to call the function. The issue that I am experiencing is that when the C program tries to load the python module NULL is returned.
#include <Python.h>
int main(int argc, char* argv[])
{
printf("Calling Python Function\n");
Py_Initialize(); // Initialize the Python interpreter.
PyObject *pName, *pModule, *pDict, *pFunc, *pArgs, *pValue; // Create some Python objects that will later be assigned values.
// Convert the file name to a Python string.
pName = PyString_FromString("ctest.py");
if (pName==NULL)
printf("file not found");
else
printf("%s\n", PyString_AsString(pName));
// Import the file as a Python module.
pModule = PyImport_Import(pName); //PROBLEM LINE
if(pModule==NULL)
printf("no Module\n");
// Create a dictionary for the contents of the module.
pDict = PyModule_GetDict(pModule);
printf("After Dictionary retrieval\n");
// Get the add method from the dictionary.
pFunc = PyDict_GetItemString(pDict, "square");
printf("after function retrieval\n");
// Convert 2 to a Python integer.
pValue = PyInt_FromLong(2);
// Call the function with the arguments.
PyObject* pResult = PyObject_CallObject(pFunc, pValue);
// Print a message if calling the method failed.
if(pResult == NULL)
printf("Calling the add method failed.\n");
// Convert the result to a long from a Python object.
long result = PyInt_AsLong(pResult);
// Destroy the Python interpreter.
Py_Finalize();
// Print the result.
printf("The result is %d.\n", result);
return 0;
}
The C Code is built with:
gcc -o pytest -lpythhon2.7 -I/usr/include/python2.7 pytest.c

Answer 1

It looks like you are running into a naming/path issue.
You might have a look at this answer:
Why does PyImport_Import fail to load a module from the current directory?