What is wrong with this class function?

Question

All parts of my program work except my one function. It takes in the argument successfully but doesn't spit out a return that I need.
https://code.sololearn.com/cmDtqD211E87/?ref=app

Answer 1

There was a website issue recently that prevented anyone from seeing new post. So no one was able to see yours including many others.
If you still require help please re add your code.