The Python/C API
Python provides an intuitive and clean C Application Programmers Interface (API) that exposes the interface to the Python runtime system. This API provides a great number of functions to manipulate Python objects and built-in types from C and C++. Most of the functions work in much the same way as they would when called from the interpreter.
To include this API in your C/C++ program, you just need to add the header "<Python.h>" to your source code.
Internally, this header file includes both Python and C header files, including: <stdio.h>, <string.h>, <errno.h>, and <stdlib.h>. Therefore, you don't need to include these again once you include "<Python.h>".
Python/C API Reference Manual (This link takes you to the official and latest documentation about the Python/C API.):
http://www.python.org/doc/current/api/api.html
Check Appendix A, "Python/C API" of this book for more details and for a complete list of the interface functions provided by the Python/C API.