main.py

import random
import string

def encrypt(plain_text, key, chars):
    cipher_text = ""
    for letter in plain_text:
        if letter in key:
            index = key.index(letter)
            cipher_text += chars[index]
        else:
            cipher_text += letter
    return cipher_text

def decrypt(cipher_text, key, chars):
    plain_text = ""
    for letter in cipher_text:
        if letter in chars:
            index = chars.index(letter)
            plain_text += key[index]
        else:
            plain_text += letter
    return plain_text
    
def main():
    chars = " " + string.punctuation + string.digits + string.ascii_letters +"ğüşiöçıĞÜŞİÖÇI"

    chars = list(chars)
    key = chars.copy()
    random.shuffle(key)
    
    cr = True
    print("******************************************")
    print("Welcome to Encryption and Decryption tool ")
    print("******************************************")

    while cr :
        print("If you wanna Encrypt your message press E ")
        print("If you wanna Decrypt your message press D ")
        print("If you wanna Quit press Q")
        option = input("(E/D/Q) ").upper()

        #Encrypt
        if option == "E":

            plain_text = input("Enter a message to encrypt: ")
            encrypted = encrypt(plain_text, key, chars)

            print(f"Original message : {plain_text}")
            print(f"Encrypted message : {encrypted}")
        #Decrypt
        elif option == "D":
            
            cipher_text = input("Enter a message to decrypt: ")
            decrypted = decrypt(cipher_text, key, chars)

            print(f"Encrypted message : {cipher_text}")
            print(f"Original message : {decrypted}")
        elif option == "Q":
            print("Bye Bye")
            cr = False
        else:
            print("Invalid input")
            

if __name__ == "__main__":
    main()