I'm trying to solve an excersice on python

Question

I\'m solving this exercise: https://www.youtube.com/watch?v=eMOA1pPVUc4&list=PLmAUnXEf_XPbdCZyDlZP2RPC4fltiK3ew&index=1&ab_channel=KeithGalli (watch 39:00 min)