Generate all base26 triplests in the fastest way

Question

I need to generate a list of triplets containing only uppercase English letters:

["AAA","AAB","AAC", ..., 'ZZZ']

What is the fastest way to do this in python?

Answer 1

>>> from itertools import product
>>> from string import ascii_uppercase
>>> triplets = map(''.join, product(ascii_uppercase, repeat=3))
>>> triplets[4]
'AAE'