source: python/vendor/Python-2.7.6/Demo/embed/demo.c

/* Example of embedding Python in another program */

#include "Python.h"

void initxyzzy(void); /* Forward */

main(int argc, char **argv)
{
    /* Pass argv[0] to the Python interpreter */
    Py_SetProgramName(argv[0]);

    /* Initialize the Python interpreter.  Required. */
    Py_Initialize();

    /* Add a static module */
    initxyzzy();

    /* Define sys.argv.  It is up to the application if you
       want this; you can also leave it undefined (since the Python
       code is generally not a main program it has no business
       touching sys.argv...) 

       If the third argument is true, sys.path is modified to include
       either the directory containing the script named by argv[0], or
       the current working directory.  This can be risky; if you run
       an application embedding Python in a directory controlled by
       someone else, attackers could put a Trojan-horse module in the
       directory (say, a file named os.py) that your application would
       then import and run.
    */
    PySys_SetArgvEx(argc, argv, 0);

    /* Do some application specific code */
    printf("Hello, brave new world\n\n");

    /* Execute some Python statements (in module __main__) */
    PyRun_SimpleString("import sys\n");
    PyRun_SimpleString("print sys.builtin_module_names\n");
    PyRun_SimpleString("print sys.modules.keys()\n");
    PyRun_SimpleString("print sys.executable\n");
    PyRun_SimpleString("print sys.argv\n");

    /* Note that you can call any public function of the Python
       interpreter here, e.g. call_object(). */

    /* Some more application specific code */
    printf("\nGoodbye, cruel world\n");

    /* Exit, cleaning up the interpreter */
    Py_Exit(0);
    /*NOTREACHED*/
}

/* A static module */

/* 'self' is not used */
static PyObject *
xyzzy_foo(PyObject *self, PyObject* args)
{
    return PyInt_FromLong(42L);
}

static PyMethodDef xyzzy_methods[] = {
    {"foo",             xyzzy_foo,      METH_NOARGS,
     "Return the meaning of everything."},
    {NULL,              NULL}           /* sentinel */
};

void
initxyzzy(void)
{
    PyImport_AddModule("xyzzy");
    Py_InitModule("xyzzy", xyzzy_methods);
}