Error in Python Embeded in Qt C++

Applications Programming
1

hi
i have an error in script language when run it
i use python 2.4, CentOS 5.5, Qt C++ 2010/04
the error is
SystemError: null argument to internal routine
the Python Code

def main(i):
    print i
 
if __name__ == "__main__":
    main(i)

the C++ Code

            PyObject *objModule = NULL;
            PyObject *objDict = NULL;
            PyObject *objExpression = NULL;
            PyObject *objArgs = NULL;
            objModule = PyImport_AddModule((char*)"__main__");
            //pValue = PyInt_FromLong(atoi(cKeyNum));
            //objArgs = PyTuple_New(1);
            //PyTuple_SetItem(objArgs, 0, pValue);
            objArgs = Py_BuildValue("(i)", cKeyNum);
            Py_IncRef(objModule);
            objDict = PyModule_GetDict(objModule);
            objExpression = PyDict_GetItemString(objDict, "main");

            //PyCodeObject *objCode = (PyCodeObject *)PyFunction_GetCode(objExpression);
            //PyEval_EvalCodeEx(objCode, objDict, NULL, objArgs, 0, NULL, 0, NULL, 0, NULL);

            //pValue = PyObject_CallObject(objExpression, objArgs);
            PyObject_CallFunction(objExpression, "", cKeyNum);

please help me to fix it