CaeserCiphercode.py

alphabet = ['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']


def encryption(plain_text, shift_key):
    cipher_text = ""
    for char in plain_text:
        if char in alphabet:
            position = alphabet.index(char)
            new_position = (position + shift_key) % 26
            cipher_text += alphabet[new_position]
        else:
            cipher_text += char
    print(f"heres is the text after encryption:{cipher_text}")


def decryption(shift_key, cipher_text):
    plain_text = ""
    for char in cipher_text:
        if char in alphabet:
           position = alphabet.index(char)
           new_position = (position - shift_key) % 26
           plain_text += alphabet[new_position]
        else:
            plain_text += char
    print(f"heres is the text after decryption:{plain_text}")
wanna_end =False
while not wanna_end:
    what_to_do = input("type 'encrypt' for encryption, type 'decrypt' for decryption:\n")
    text = input("type your message:\n")
    shift = int(input("enter shift key:\n"))
    if what_to_do == "encrypt":
        encryption(text, shift)
    elif what_to_do == "decrypt":
        decryption(text, shift)
    play_again = input("type yes to continue, type no to stop:")
    if play_again == 'no':
        wanna_end = true
        print("have a nice day bye")
    else:
        print("lets go again")