How to iterate through the alphabet? [duplicate]

Question

How can I iterate through the alphabet and have it continue past the letter Z? For example - a,b,c ... y,x,aa,ab,ac,ad

At the momenent this is my array

letters = [
           "a","b","c","d","e","f","g","h","i","k",
           "l","m","n","o","p","q","r","s","t","u",
           "v","w","x","y","z", "aa", "ab", "ac", "ad", "ae",
           "af", "ag", "ah", "ai", "aj", "ak", "al", "am", "an",
           "ao", "ap", "aq", "ar", "as", "at", "au", "av","aw", "ax", "ay",
           "az", "ba", "bb", "bc", "bd", "be", "bf", "bg", "bh", "bi",
           "bj", "bk", "bl", "bm", "bn", "bo", "bp", "bq", "br", "bs", "bt",
           "bu", "bv","bw", "bx", "by", "bz","ca","cb","cc","cd","ce",
           "cf","cg","ch","ci","cj","ck","cl","cm","cn","co","cp",
           "cq","cr","cs","ct","cu","cv","cw"]

but I want to make it created within a loop.

Answer 1

You can try this:

import string

letters = list(string.ascii_lowercase)

letters.extend([i+b for i in letters for b in letters])

print letters

By using a double for loop, we iterate over the alphabet like we normally would, except we can put the iteration in list comprehension, to save space and be more pythonic.

Answer 2

since string.ascii_lowercase holds all of the lower-case letters, you can iterate through them in one loop (for 1-letter-string) or two (for 2-letters-string) and just add them to a list, like this:

import string
list = []
for c in string.ascii_lowercase: 
    list.append(c)

for c1 in string.ascii_lowercase:
    for c2 in string.ascii_lowercase:
        list.append(c1+c2)

print(list)