为什么打印功能命令两次？ [关闭]

Question

下面的python代码是我的凯撒密码项目

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', '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']

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"))
def caesar(plain_text,shift_num,direction):
  if direction == "encode":
    encoded_text = ''
    for letter in plain_text:
      encoded_text = ''
      encoded_text += alphabet[alphabet.index(letter)+shift_num]
    print(f"the encoded text is {encoded_text}")
  elif direction == "decode":
    decoded_text = ''
    for letter in plain_text:
      decoded_text += alphabet[alphabet.index(letter)-shift_num]
    print(f"the decoded text is {decoded_text}")
caesar(plain_text = text,shift_num = shift,direction=direction)

上面的代码执行了一个控制台，打印功能被执行了两次。对于编码和解码，打印功能有两个答案。为什么我的代码会遇到这个问题？

Answer 1

给你：- 改进版。我导入了字符串，因此您不必制作字母列表。

import string
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"))
def caesar(plain_text,shift_num,direction):
    e_msg = ""
    if direction == "encode":
        for i in plain_text:
            if not i == " ":
                e_msg += string.ascii_lowercase[(string.ascii_lowercase.index(i) + shift) % 26]
            else:
                e_msg += " "
        print(e_msg)
    elif direction == "decode":
        for i in plain_text:
            if not i == " ":
                e_msg += string.ascii_lowercase[(string.ascii_lowercase.index(i) - shift) % 26]
            else:
                e_msg += " "
        print(e_msg)

caesar(plain_text = text,shift_num = shift,direction=direction)