Why is my cat being mean!?

I dont know if shes being mean or playful, she is about 7 months old. Every time I put my hand up to pet her she leaps at it and bites me and when I sneak my hand behind her to pet her she turns around and bites me! Im use to cats that snuggle and pure but she doesnt do any of that, and she growls if you hold her to long and she looooooves to play so is she just acting like a kitten? will she grow of it?