I'm unsure about an answer for the first part of the question but I can answer the second one.
(before reading my answer remember all snakes have individual personalities to some degree having said that)
The majority of carpet pythons are non aggressive at to any degree. If you get a baby carpet python expect it to be nippy for at least three weeks if it strikes@ all. most baby snakes (even a rare corn snake) will strike until it either reaches a size that it feels it will be safe around you or you interact with it on a daily basis (picking it up for five minutes or less, cleaning its cage without touching it but putting your hands in there so it gets to being around them). Once youve had your carpet baby (ies) for a good two - three weeks handled on a regular basis they should stop nipping at all together and once they calm down its a permanent thing. The only time you might get bitten is from a feeding response but a great feeding response is better than a low to no feeding response@ all.