in reply to How to make index.pl the default?

That isn't really a Perl question, is it? I suggest asking in the Python community how to make index.py the default, and then replace py with pl in their answer.

Or you could just read the manual page of your server, because it's a server issue, and it depends on the server whether this is possible, and if, how. The language in which the program is written it totally irrelevant.

Abigail