# IndexError comes because you are trying to get the item that don't exists 
# it means if you ant to get the numbers

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9 10]
length_of_numbers = len(numbers)

printnumbers(length_of_numbers)        # raises IndexError because the len() 
# function starts counting from 1 but the index sarts counting from 0