Honestly my ball pythons all pretty much have the same "personality". Shy and skittish and can be somewhat stubborn at times when it comes to feeding..

In contrast though, my boa, retic, carpet, and African house snake all have very different and distinct personalities and intelligence.

The retic has that retic intelligence. Always watching everything you do. Learns from past experience. Very expressive. Holds grudges. Etc.

The boa is very sweet, laid back but active, seems smart and knows the difference between feeding time and handling time when the cage door is opened.

The carpet is still a bit feisty and always hungry but he knows people are no danger. He knows how to ask for food and will intently stare at you to ask for food.

The house snake will stare at his food bowl to let you know he wants food. He has an interesting and quirky personality. Very curious and likes to watch what's going on similar to the retic.

In my opinion, after working with different species of snakes, if any snakes could be classified as having a personality, I believe ball pythons have the least amount of personality of the bunch.