A brute force sudoku solver, written in C, compiled to a DLL and wrapped with Python ctypes.

Almost any Python introduction has a part in it somewhere stating, that if your code is somehow too slow, you can always extend it in C. It's something I was happy to repeat, when selling Python to other programmers, meanwhile hoping they wouldn't ask me how that would actually work, because I wouldn't be able to tell them.... until now.

http://www.gumuz.nl/blog/2008/02/02/simple-python-extensions-using-ctypes/