Day8_Caesar 암호 최종, 코드 재구성(하나의 함수로 정리)

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']
import art #from art import logo
print(art.logo)
def caesar(text,shift,direction):
    output_text=''
    if direction == "encode":
        for char in text: 
            if char in alphabet and ((alphabet.index(char))+shift) <= 25:
                output_text += alphabet[(alphabet.index(char))+shift]
            elif char in alphabet and ((alphabet.index(char))+shift) > 25:
                output_text += alphabet[((alphabet.index(char))+shift)%26]
            else:
                output_text += char
        #print(f"The {direction}ed text is \'{''.join(input_txt)}\'.")
        print(f"The {direction}ed text is \'{output_text}\'.")
    elif direction == "decode":
        for char in text:
            if char in alphabet and ((alphabet.index(char))-shift) >= 0:
                output_text += alphabet[(alphabet.index(char))-shift]
            elif char in alphabet and ((alphabet.index(char))-shift) < 0:
                output_text += alphabet[((alphabet.index(char))-shift)%26]
            else:
                output_text += char
        print(f"The {direction}ed text is \'{output_text}\'.")
    else :
        print("Error! Type 'encode' to encrypt, type 'decode' to decrypt.")
repeat = True
while repeat:        
    direction = input("Type 'encode' to encrypt, type 'decode' to decrypt:\n")
    text = input("Type your message:\n").lower()
    shift = int(input("Type the shift number:\n"))
    caesar(text,shift,direction)
    restart = input("Type 'yes if you want to go again. Otherwise type 'no'.\n")
    if restart == "no":
        repeat = False
        print("Goodbye")