Linds is exactly correct!!!

I had a Blood Python once that was a real SOB
and it had no pupil reaction in one eye.. The pupil was wide open all the time.. This probably accounted for its extreme nastiness.
It's rarely done by new owners, but its a good idea to check new acquisitions to see if their eyes are functioning.
Snakes will somtimes seme a bit dumb and bump into stuff but they should be able to go around things.
In addition to the eyes, make sure it has a tongue that functions... and that it's mobility doesnt seem impaired.
Impactions and other internal problems can make snakes have a hard time moving properly on rare occasions... give it a good check over