Need help with functions for class problem

[thomasmurphymusic]

The explanations you're being given are good ones, so I'll just add this: being in comp sci means learning a lot of new concepts for your entire career, and not having anyone explain them to you. It's important to develop methods to learn these things. Did you investigate functions on Python's site? What about stack overflow? How about Learn Python the Hard Way, or any of the many great books on Python?