I need help with this python programming assignment. I am not sure why my function is not working properly.

def average(grades): # function grades = list(grades) total = sum(grades) average_1 = total / (len(grades)) # takes additive total of grades and divides it by the number of grades provided return average_1 # returns grades provided average print("Hello, welcome to the TVDSB grade calc, please enter 6 grades, each separated by a comma") grades = list(input()) average(grades) print("The average for the 6 grades provided is " + str(average_1))