Very cute 0.0 ball python in your sig.

Others have already mentioned what to look for. I just wanted to stress (as I always do in these posts) that once you get a snake (this one or any other), have a vet already chosen, preferably a reptile specialist. What you'll want to do is make an appointment and have the snake checked out fully within a few days. You can ask them to sex (probe) it, however, many will refuse when they are still small.