Hello, my code for Part of the Whole isn't working.
this is the exercise link, because I apparently need to put that:
I run the below code, and I get this error: "Oops, try again. get_class_average([alice]) resulted in an error: unsupported operand type(s) for +: 'int' and 'NoneType'"
def get_class_average(students): results =  for x in students: results.append(get_average(x)) return average(results)
Can anyone suggest what is wrong? Thanks in advance