embedding python

Question

Im trying to call python functions from C code, and i followed a sample from here

I also have the correct include file directries, library directries, and linked the python32.lib (im using python 32) however the error was that python/C APIs such as PyString_FromString, PyInt_FromLong, PyInt_AsLong are undefined (error in the debugger)

this is strange because im also using other APIs, but they're all fine...

whats the problem here??

int
main(int argc, char *argv[])
{
    PyObject *pName, *pModule, *pDict, *pFunc;
    PyObject *pArgs, *pValue;
    int i;

    if (argc < 3) {
        fprintf(stderr,"Usage: call pythonfile funcname [args]\n");
        return 1;
    }

    Py_Initialize();
    pName = PyString_FromString(argv[1]);
    /* Error checking of pName left out */

    pModule = PyImport_Import(pName);
    Py_DECREF(pName);

    if (pModule != NULL) {
        pDict = PyModule_GetDict(pModule);
        /* pDict is a borrowed reference */

Py_Initialize(), PyImport_Import(), PyModule_GetDict() all work fine, but not PyString_FromString...

I really think that the function PyString_FromString was renamed to PyBytes_FromString into the Python 3.x. — Tarantula
– Tarantula, Commented Nov 22, 2011 at 16:08

yak · Accepted Answer · 2011-11-22 16:13:31Z

18

The example code you used is for ancient Python version, 2.3.2. Python 3.x line introduced a number of incompatibilites not only in the language but in the C API as well.

The functions you mention simply no longer exist in Python 3.2.

PyString_ functions were renamed to PyBytes_.

PyInt_ functions are gone, PyLong_ should be used instead.

Here's the same example that you've used but for Python 3:

5.3. Pure Embedding

Note that it's using PyUnicode_ instead of PyString_/PyBytes_. In many places where Python 2.x used byte strings, Python 3.x uses unicode strings.

By the way, I usually use this page to look up all possible calls:

Index – P

edited Nov 22, 2011 at 16:13

answered Nov 22, 2011 at 16:01

yak

9,1012 gold badges34 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

PeterG Over a year ago

so i followed ur suggestion and it worked. now i want to test it using the documentation example you've provided. do i go into the .exe directry and cmd 'call multiply multiply 3 2' ??

yak Over a year ago

I think so, yes, assuming the exe file is called call. If you get stuck, ask a separate question.

Collectives™ on Stack Overflow

embedding python

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related