If your ball python was large enough and also wide enough to properly swallow humans, he'd most likely eat you if he were to get hungry. So on that basis i wouldn't consider a BP domesticated. Also reptiles don't have mammal type instincts (such as social instincts which are present in both cats and dogs) and inorder to properly "domesticate" them you'd have to change their instincts which without MASSIVE efforts of selective breeding for desired docility; snakes won't become domesticated anytime soon.