Extending the python language

I'm writing a class definition in python with some array atributes
from Numeric 2.0. I'm using UserArray, UserList, to subclass my
classes. But some of the methods I need to write in C mainly because
of computing speed. I need to pass to those C functions array and
lists objects that the C functions can access their contained values
like arrays and lists.
My question is that do I need to provide a python 'class' definition
to the C functions for those functions to be able to access these
subclassed classes and their attributes?
Is there software out there that can automate this particular
procedure?

Thanks,

John D.