I currently have several ball pythons and a tortoise, and I would say go with the snake! Tortoises are much higher maintenance, have stricter lighting requirements, eat more often, etc. Harder to go away for a weekend/short vacation with a tortoise than it is with a snake, which I think is something important to consider. That being said, tortoises are pretty awesome and much more interactive!

Good luck with your decision, really can't go wrong either way