I used swig for a long time. It's really handy.

If you're just targetting python, and it's your first venture into building python extensions, it's fantastic. After a while, it's worth trying out building an extension without the use of swig. Much of the time, it's easier to use than swig is - but you do have to implement all the bells and whistles yourself. If you're writing in C or C++, chances are you like that kind of thing anyway.