extending Python - passing nested lists

[Christian Meesters]

Thanks. Point is that all such approaches would require lots(!) of calls to
the Python API - a way by which I won't gain the desired speed. 

I've tried pyrex and the corresponding C-file is so convoluted with dummy
variables, incrementing & decrementing references, and other stuff, that I
want to try to write a C-function myself. My goal is not to avoid 
PyObjects* and the corresponding reference handling - apart from the head
and end of the function. (I could use ctypes instead, but that again would
obfuscate the API of my package a bit.)

Christian