I think it depends a lot on the snake, and I do not subscribe to the idea that "one schedule fits all", with snakes (or people for that matter). However, as a general guideline, I keep my snakes on a "slow" feeding schedule; naturally, snakes stock up on food because in the wild they may not be able to find another meal for weeks or months. I.e., they don't stop eating when they're full. With this in mind, I personally would not feed a ball python more than once per week.