import?pyperclip
LETTERS?=?'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
def?main():
???myMessage?=?"This?is?basic?implementation?of?Vignere?Cipher"
???myKey?=?'PIZZA'
???myMode?=?'encrypt'??
???if?myMode?==?'encrypt':
??????translated?=?encryptMessage(myKey,?myMessage)
???elif?myMode?==?'decrypt':
??????translated?=?decryptMessage(myKey,?myMessage)??
???print('%sed?message:'?%?(myMode.title()))
???print(translated)
???print()
def?encryptMessage(key,?message):
???return?translateMessage(key,?message,?'encrypt')
def?decryptMessage(key,?message):
???return?translateMessage(key,?message,?'decrypt')
def?translateMessage(key,?message,?mode):
???translated?=?[]?#?stores?the?encrypted/decrypted?message?string
???keyIndex?=?0
???key?=?key.upper()
???for?symbol?in?message:
??????num?=?LETTERS.find(symbol.upper())
??????if?num?!=?-1:
?????????if?mode?==?'encrypt':
????????????num?+=?LETTERS.find(key[keyIndex])
elif?mode?==?'decrypt':
???????????????num?-=?LETTERS.find(key[keyIndex])
????????????num?%=?len(LETTERS)????????????
????????????if?symbol.isupper():
???????????????translated.append(LETTERS[num])
????????????elif?symbol.islower():
???????????????translated.append(LETTERS[num].lower())
????????????keyIndex?+=?1
????????????
????????????if?keyIndex?==?len(key):
???????????????keyIndex?=?0
?????????else:
????????????translated.append(symbol)
??????return?''.join(translated)
if?__name__?==?'__main__':
???main()