Adopted snake, need help IDing.

[Exelightning]

Hello, first things first. I have owned many ball pythons, and corn snakes in my life, and feel the time is right to make the jump I've been waiting a while for. Anyways, I recently adopted this "Burm", but they told me it was two years old, and only about 4.5 feet long. Is it possible that a Burmese python would only grow to that size in two years if it wasn't fed enough/had a large enough aquarium? Anyways, I'm including some photos and if anyone could let me know if they thinks this truly is a Burm, or a ball python, I would be very grateful.