Q/Write a program that can encrypt and decrypt using the affine cipher

AffineCipher.py

import string

def AffineEncrypt(input :string, key1: int, key2: int):
    input = input.replace(" ", "")
    result = ""
    for letter in input:
        cipheredLetter = (GetLetterIndex(letter)*key1+key2)%26
        result += GetLetterFromIndex(cipheredLetter)
    return result



def AffineDecrypt(input, key1, key2):
    result = ""
    for letter in input:
        uncipheredLetter = ((GetLetterIndex(letter)-key2)*pow(key1, -1, 26))%26
        result += GetLetterFromIndex(uncipheredLetter)
    return result



def GetLetterIndex(letter):
    return string.ascii_uppercase.index(letter.upper()) 

def GetLetterFromIndex(index):
    return string.ascii_uppercase[index]



input = "hello"
key = (7,2)

cipherText = AffineEncrypt(input, key[0], key[1])
uncipheredText = AffineDecrypt(cipherText, key[0], key[1])

print(cipherText) #print ZEBBW
print(uncipheredText) #print HELLO