Python: TypeError: 'NoneType' object is not subscriptable

Question

#Uses python3

import sys

def max_dot_product(a,b,n):


    a = a.sort(reverse=True)
    b = b.sort(reverse=True)
    res = 0

    for i in range(n):
        res +=         


        

Answer 1

sort sorts a list in place and (implicitly) returns None. Drop the assignment of the return value and you should be OK:

a.sort(reverse=True)
b.sort(reverse=True)