How to find the longest list in a list?

Question

Given a list of lists, the length of the longest list can be found with the following code.

values = [['a','a'], ['a','b','b'], ['a','b','b','a'], ['a','b','c','a']]

longest = 0
for value in values:
    longest = max(longest, len(value))

print(longest)
[out]: 4

How can the length of the longest list, or the longest list be found, without a loop.

Answer 1

This will return the longest list in the list values:

max(values, key=len)

Answer 2

This will return the length of the longest list:

max(map(len, values))