Example of writing extension with c++ for python with cpython.

README.md

How to build

• python3 setup.py build
• From current directory, cd build/lib.linux-x86_64-3.6 (tested on Ubuntu 18.04 with python 3.6.7).
• python3 to enter interactive mode
• import spam
• spam.system('ls -la') then it should print the current directory listing as output

setup.py

#!/usr/bin/env python3
# encoding: utf-8

from distutils.core import setup, Extension

spam_module = Extension('spam', sources=['spammodule.cpp'])

setup(name='spam',
      version='0.1.0',
      description='Spammodule written in C++',
      ext_modules=[spam_module])

spammodule.cpp

#define PY_SSIZE_T_CLEAN
#include <Python.h>

static PyObject *spam_system(PyObject *self, PyObject *args)
{
    const char *command;
    int sts;

    if (!PyArg_ParseTuple(args, "s", &command))
        return NULL;

    sts = system(command);
    return PyLong_FromLong(sts);
}

// module methods
static PyMethodDef SpamModuleMethods[] = {
    { "system", spam_system, METH_VARARGS, "Execute system's command line from input string." }
};
// module definition
static PyModuleDef SpamModuleDef = {
    PyModuleDef_HEAD_INIT,
    "SpamModule",
    "SpamModule for practicing",
    -1,
    SpamModuleMethods
};

PyMODINIT_FUNC PyInit_spam(void)
{
    Py_Initialize();
    return PyModule_Create(&SpamModuleDef);
}