I find that most ball pythons take about 3 to 4 years to be fully grown. Males about 3 yrs females about 4. But that doesn't necessarily mean they aren't ready to breed before 3 to 4 yrs. Males can breed sometimes as early a 5 months, females about 2 years until sexual maturity.

Quote Originally Posted by mcavana View Post
but they never stop growing.
True, but after about 3 years their growth rate slows majorly. That would also be why they shed less, and over a longer duration of time.