How to check the version of the python API at compile time from a C extension module?

Question

I am writing a python module in C. The module needs to be compiled for python version 2.4, 2.5, 2.6 and 2.7.

Now I ran in to the problem that in python 2.5 they defined Py_ssize_t for the size of lists, but in 2.4 they just used int.

So my question is: Is there an easy way to check if I'm using the API of version 2.4 or 2.5 at compile time so I can write a little macro?

e.g:

#if PY_MINOR < 5
typedef int Py_ssize_t;
#endif

Answer 1

Yes, patchlevel.h in the Python include dir defines what you are looking for:

#define PY_MAJOR_VERSION    2
#define PY_MINOR_VERSION    5
#define PY_MICRO_VERSION    2