Completely depends on species. Carpets in general are usually known to be nippy buggers as babies but they really settle down well with age...Jungle carpets are known to be slightly more nippy than coastal carpets overall. Coastal carpets are known for having fantastic temperament as adults but do get larger. I do not own a GTP but I know they're rather nippy overall, then again I have watched several videos where adult specimens are handled without issue. Still, a GTP is not a beginner snake at all.

When I think of "aggressive python" the only species that really comes to mind are white lipped pythons, I'm sure someone can shed more light on this though.