If you are really only 15 years old, ask yourself where you will be in 15 more years. College, girls, friends, moves and jobs are not typically reticulated python friendly at least retics that go 9+ feet.
I agree they are an exciting snake, but they require FULL, stable commitment and should not be purchased on impulse.
This. I would recommend holding off on getting one until you're paying a mortgage and not rent. Heck many landlords freak out about ball pythons and king snakes.