Python Pocket Reference, Second Edition

Major Python/C API Tools

These Python/C integration tools, available in the C library generated when Python is compiled, are used to call Python from C (embedding) and call C from Python (extending). Note that the SWIG system (among others) can automate much C extension module coding, and the Distutils tool is useful for building extensions. See the Python/C API manual for additional details and calls omitted here.

General

#include "Python.h"

Main Python C include file; defines the Python/C API.

libpython2.2.a, python22.dll, etc. (platform-dependent)

Python C library, when linked-in in embedded mode.

PyObject*

Type signature of a generic Python object in a C program.

Py_Initialize( )

Called to initialize linked-in Python libraries in embedded mode.

Py_InitModule(char *name, PyMethodDef methods_table[])

C extension module initialization call in extending mode.

Reference Counts

void Py_INCREF(PyObject *o), void Py_XINCREF(PyObject *o)

Increments the reference count for object o. Second format has no effect if o is NULL.

void Py_DECREF(PyObject *o), void Py_XDECREF(PyObject *o)

Decrements the reference count for object o. Second format has no effect if o is NULL.

Data Translation

int PyArg_ParseTuple(PyObject *arg, char *format, ...);

Converts a Python tuple to C values. arg must be a tuple (e.g., an argument list passed to a C function). format is a conversion format string, whose syntax is given in Table 1-25 and in the Python/C API manual (e.g., si specifies string and integer conversions). ...