Why won't this work???

Jr. King n at n.com
Tue Jun 1 16:45:25 CEST 1999

I know you are getting tired of me, but I have tried repeatedly to solve
this on my own and I can't get it to work.
I am trying to do a python callback to call from a c/c++ program.
Here is the c/c++ code

// learnPyth.cpp : Defines the entry point for the console application.

#include "stdafx.h"
#include "python.h"
#include "stdio.h"
#include <iostream.h>
#include <windows.h>

static PyObject *my_callback = NULL;

static PyObject* Test(PyObject *self, PyObject* args){
 int command;
 int aoe;
    if (!PyArg_ParseTuple(args, "ii", &command,&aoe))
        return NULL;

 int xs(5);
 PyObject* xarg = Py_BuildValue("(i)",xs);

 PyEval_CallObject(my_callback, xarg);//python returns the PYNone thingie

 return args;

static PyObject* setCallback(PyObject *self, PyObject* args){
    PyObject *result = NULL;
    PyObject *temp;

    if (PyArg_ParseTuple(args, "O:set_callback", &temp)) {
        if (!PyCallable_Check(temp)) {
            PyErr_SetString(PyExc_TypeError, "parameter must be callable");
            return NULL;
        Py_XINCREF(temp);         /* Add a reference to new callback */
        Py_XDECREF(my_callback);  /* Dispose of previous callback */
        my_callback = temp;       /* Remember new callback */
        /* Boilerplate to return "None" */
        result = Py_None;
    return result;

static PyMethodDef meths[]={
 {"testmeth", Test, METH_VARARGS},
 {"setCallback", setCallback, METH_VARARGS},
 {NULL,  NULL}  /* sentinel */

int main(int argc, char* argv[])
 char input[200];
 int ret;
 FILE *fp;
 fp = fopen("beer.py","r+");
 Py_InitModule("testmeth", meths);
 if(fp == NULL)
  cout<<"Didn't open file";
  ret = PyRun_AnyFile(fp,"beer.py");
 return 0;

Here is the python code

#! /usr/bin/env python
# By GvR, demystified after a version by Fredrik Lundh.
#import sys
import testmeth
import setCallback
n = 20
#if sys.argv[1:]: n = int(sys.argv[1])

def setN(x):
 x = n
 print n

def bottle(n):
    if n == 0: return "no more bottles of beer"
    if n == 1: return "one bottle of beer"
    return str(n) + " bottles of beer"

for i in range(n):
    #print bottle(n-i), "on the wall,"
    #print bottle(n-i) + "."
    #print "Take one down, pass it around,"
    print bottle(n-i-1), "on the wall."

print n

thanks again.

More information about the Python-list mailing list