Why is function call - recursive especially - in python so slow?

[iviskic at uci.edu]

Hi,

I'm doing an analysis of program code performance when written in python
as oppose to other programming languages, and can't seem to figure out why
is the call of functions so slow?
Is a context being created and stored on stog each time, or does it uses
references? How EXACTLY does it work? I've read the documentation, but it
is written on a cooking-book principle, so it does not say clearly how it
works, just that it does work.

Please let me know if you now how it's done, or (preferably) point me
where to look for the answer.
Thank you in advance.

Ines