At the very least, you'll need to have the following lines in your Apache configuration file:
PythonHandler pse_handler AddHandler python-program .pt
The first directive instructs mod_python to use pse_handler to
handle all python requests. The second directive says that anything
that ends in .pt should be handled by the python handler
(pse_handler).
There are very very few situations where you would want to change these lines. This works pretty much universally.