That sounds like he's hoping for a mouse, actually.

My het pied used to do that, too, watching me clean his tank. Eventually he decided he didn't like it, and he started "guarding" his tank from cleaning. He would also "hunt" my toes when he was out on the couch. Good old Mr. Nibbles...

I'd wear mittens/gloves if your ball python is intimidating you when cleaning his tank. It's got to get done. And I'd start feeding him in a cardboard box, so that he doesn't associate you sticking your hand in the tank with Lunchtime. I'd also up his mouse quota for a while, see if he'll accept seconds.

Just in general, some of them are more timid than others. Some of them are sweet, some of them are outgoing, some of them are downright grumpy. They all get less timid/grumpy with handling, and I have one hatchling that will actually climb my hand when I offer it to her. But even my really neurotic snakes will skip being timid when they're hungry.

So I'd definitely trying offering a little more food.

If your guy does turn into a "Mr. Nibbles", the good news is, it won't last past the first year. I've had two biters, and they both turned sweet as soon as they hit their juvenile fast and the hormones turned on.