A full grown cat would be more than a match for a full grown ball python.
the snake has quick strike, and muscle, but the cat is far greater armed, with huge fangs and razor sharp claws.
ignorance! The ball python is the one at risk, in a fair fight, my money wiuld be on the cat. They are fearsome predators.
regardless of these facts, you describe yourself as an exceptionally resonsible pet owner, and i doubt you would ever allow the two predators to be in contact. I wish you a fair trial, and your new pet cat is not unjustly taken from you.