I don't consider ball pythons to ever be aggressive. They almost always have a reason for striking or biting. Either they are exhibiting a strong feeding response (not being fed enough, close to feeding day) or they are terrified (big gigantic monster coming to pick me up). You would be scared too!
The best thing you can do is let the snake have some alone time and take it out for short 10-15 minute handling sessions. Over handling can stress it out.
Also, cage aggression is not a problem with this species. They are very shy, nervous snakes. As long as you go in the cage one other time during the week (lets say to clean or take the snake out) no association between "hand and food" will be made. If you feed outside the enclosure, your chance of getting bit goes up drastically. The more times you put your hand into the feeding process, the more opportunities your snake has to bite. I feed all my snakes in their home enclosures and I have never been bit (knock on wood!!). I never handle my snake on feeding day or two days after to allow for a digestion period. I don't handle my snakes when they are hungry. As long as you feed your snake enough and handle him a couple times a week, he should never associate your hand with being fed.
Not to mention being fed outside the home enclosure can become stressful for some ball pythons. Eating is a vulnerable time for them and they would prefer to be in an area they knew was safe rather then an empty plastic tub or bucket...