How to create a list of English alphabet letters (from A to Z) with python ?

Examples of how to create a list of English alphabet letters (from A to Z) with python:

List of alphabet letters (lowercase)

To get a list of English alphabet letters with python, a straightforward solution is to use the library called string

import string

english_alphabet_string_lowercase = string.ascii_lowercase

english_alphabet_string_lowercase

gives

'abcdefghijklmnopqrstuvwxyz'

Then to transform the above string to a list, just use the list() function:

english_alphabet_string_lowercase_list = list(english_alphabet_string_lowercase)

print( english_alphabet_string_lowercase_list )

gives

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

Note: if you want to upper case a given letter, b for instance:

english_alphabet_string_lowercase_list[1]

'b'

a solution is to use the method upper():

english_alphabet_string_lowercase_list[1]  =     english_alphabet_string_lowercase_list[1].upper()

print( english_alphabet_string_lowercase_list )

gives

['a', 'B', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

List of alphabet letters in (uppercase)

To create a list of alphabet letters in uppercase, we can use a list comprehension:

[l.upper() for l in english_alphabet_string_lowercase]

gives

['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']

or directly from the library sring:

english_alphabet_string_uppercase= string.ascii_uppercase

english_alphabet_string_uppercase

gives

'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

then create a list using list() method:

english_alphabet_string_uppercase_list = list(english_alphabet_string_uppercase)

print( english_alphabet_string_uppercase_list )

gives

['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']

Note: same to transform a given letter from uppercase to lowercase

english_alphabet_string_uppercase_list[1]

B

english_alphabet_string_uppercase_list[1].lower()

b

List of lowercase and uppercase alphabet letters

alphabet = list(string.ascii_lowercase) + list(string.ascii_uppercase)

gives

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']

Example of application: create a simple coded message

Create a list of alphabet letters

a1 = list(string.ascii_lowercase) + list(string.ascii_uppercase)

print( alphabet )

gives

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']

Rotate elements of the previous list

from collections import deque

a2 = deque( a1 )

a2.rotate(2)

print( list( a2 ) )

gives

['Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X']

Create a secret dictionary

secret = {}
for letter, coded_letter in zip(a1,a2):
    secret[letter] = coded_letter

and a function to encode a word:

def encoder_function(letter):
    return secret[letter]

Now let's encode the word 'Hello':

s = 'Hello'
s = list(s)

print( encoder_function('a') )

''.join( list( map(encoder_function, s) ) )

gives

'Fcjjm'