Question

I have a function that have to return True if and only if all the ints in L1 are the lengths of the strings in L2 at the corresponding positions. and the Precondition: len(L1) == len(L2).

EXAMPLE:

>>> are_lengths_of_strs([4, 0, 2], ['abcd', '', 'ef']) 
True

Below is the function:

def are_lengths_of_strs(L1, L2):
    result = True
    for i in range(len(L1)):
        if i in len(L1) != len(L2):
            result = False
    return result

It result in a error. The line if i in len(L1) != len(L2): is the wrong . Can someone help me in this line ??

Obs : I have to use !=

Answer 1

Corrected version of your code:

def are_lengths_of_strs(L1, L2):
    result = True
    for i in range(len(L1)):
        if L1[i] != len(L2[i]):
            result = False
    return result

Note that this is not pythonic, because you don’t in fact need an index here:

def are_lengths_of_strs(L1, L2):
    result = True
    for i, l in zip(L1, L2)
        if i != len(l):
            result = False
    return result

Even shorter:

def are_lengths_of_strs(L1, L2):
    return all(i == len(l)
        for i, l in zip(L1, L2))