This video show you how to make an installable Debian package (".deb") out of a python program. The example program to demonstrate this technique is a little python game called "rock, paper, scissors".
Making a little python program is fun. Showing that program to other users in the Linux (Ubuntu) world is troublesome - not everyone understands how to work with the command line, how to install necessary packages and how to create a neat menu entry. A .deb installer can make this much easier.