Python Inheritance - A C example (without third party libraries)

[Aaron Drew]

Can someone give me a source code example of how to derive a python class
(written in C) from another python class (also written in C) such that I
can:

a. Derive further classes from it (in python)
b. Determine if a derived class is a subclass of a particular base class (in
C)

I know there are resources such as CXX, SCXX and the boost library but none
of these seem to make it clear and the python doc's aren't up to scratch in
this area.

Thanks,
Aaron