[rogerbinns]

My C module is APSW - a python wrapper around SQLite - https://code.google.com/p/apsw/

It supports every version of Python from 2.3 onwards with the exception of 3.0. I provide binaries for Windows and astonishingly people are still downloading the 2.3 version.

As you stated, most of the work is done by feeding the C preprocessor relevant information - https://code.google.com/p/apsw/source/browse/src/pyutil.c

It did take me considerably longer to make my test suite work. This is because I have 99.6% code coverage, and it exercises a lot of edge/error conditions. The test suite code (in Python) is written to run under both Python 2 and 3 as is and has to use some of the similar tricks with exec as the article mentioned. Fun challenges are constructing invalid UTF8 sequences in all Python versions and that sort of thing.