You can install PiSi on your system with a single command.

# ./setup.py install

If you are on a Pardus system, you should delete /usr/lib/pardus/pisi
when you are installing the SVN version

PiSi requires piksemel XML processing library, Pardus configuration 
manager COMAR and COMAR API in order to run.

If you are upgrading from an old PiSi release you may have to 
run the following command as root:

# pisi rebuild-db