One thing I have noticed in my short time in this hobby is that Ball Pythons eat, when Ball Pythons want to eat.
What I am finding is that when I watch the queue's that my Ball Python gives out when he is hungry, he ends up eating anywhere between 9-13 days.
I look for him to be hunting for prey on 3 consecutive nights before I feed him.
This is where the glass cage is king...
The first night, he might just cruise around a few times and then go into his hide.
The second night he will cruise around for an hour or two, but then retreats to his hide.
The Third night he normally will come out 1-2 hours before sundown and begin his hunt. I've waited 3-4 hours and he's still crusin around and poking his head up to the top of the tank.
This is when I feed him.
I think we all get sucked into the "It has to eat every Saturday on Saturday or I'm a failure as a pet owner" but the reality is that it's a Ball Python and it's going to eat when it wants to. The best thing you can do is keep their enclosures (whatever kind you prefer) as balanced and comfortable as possible.
They're animals, they don't abide by logic. However animal instinct, is actually quite easy to predict.