what snake who people must be carefully with snake?

Well, if its a matter of being cautious id say Rattlesnakes and Pythongs. These snakes are poisonous, and commonly encountered on nearby areas. Rattlesnakes likes cold places to hide away from summer heat, that's why some of them choses to hide on basements and garages. That is why there are a lot of encounters of rattlesnakes with humans, which we should be wary about.

as for being careful with snake depends on what you mean? Which snakes are more aggressive than others that you can purchase from a pet store. You probably want to stay away from reticulated pythons due to size and temperment. I would also stay away from burmese pythons as well, really big snake and eventually you be feeding these two snakes large rabbits or a small goat. Tree pythons don't make good pets unless you just want an ornimental snake (they have big fangs which allow them to strike from trees and hold on to their pray). Snakes that make good house pets, are like the ball python, corn or milk snakes, things of a smaller nature, plus it will keep food costs down.