It's best to house your ball pythons separately on a permanent basis so that they don't have to compete for space, security, or thermoregulation, but at the very least it is advisable to do as Raj suggested and quarantine for an adequate period (MINIMUM 30 days, 90 is better).

By the way, as far as almost all of us are concerned, n00b questions are WELCOMED here. We would far rather you ask questions and learn than not ask and risk making a dangerous mistake. Your roommate should look into setting up a Sterilite setup, as they're inexpensive to set up and easy to maintain, and may be a good choice for him.