python - 为什么我的凯撒轮班不能正常工作？

Question

这是代码：

text = input("What's your text:  ")
shift = int(input("What's your shift: "))

def caesar_shift(text, shift):
    cipher = ""
    for i in text:
        if i.isalpha():
            stayIn = ord(i) + shift
            if stayIn > ord('z'):
                stayIn -= 26
            lastLetter = chr(stayIn)
        cipher += lastLetter

        print("Your ciphertext is: ", cipher)

    return cipher

caesar_shift(text, shift)

当我运行它时，例如，测试是 hello world，shift 是 1，我得到：

What's your text:  hello world
What's your shift: 1
Your ciphertext is:  i
Your ciphertext is:  if
Your ciphertext is:  ifm
Your ciphertext is:  ifmm
Your ciphertext is:  ifmmp
Your ciphertext is:  ifmmpp
Your ciphertext is:  ifmmppx
Your ciphertext is:  ifmmppxp
Your ciphertext is:  ifmmppxps
Your ciphertext is:  ifmmppxpsm
Your ciphertext is:  ifmmppxpsme

为什么是这样？我做错了什么，提前谢谢！

Answer 1

你做

if i.isalpha():

但是如果你没有其他条款。这意味着当它不是字母时，您也添加最后一个字母。因此ifmmpp，而不是ifmmpfor hello。

该位应更改为：

if i.isalpha():
    stayIn = ord(i) + shift
    if stayIn > ord('z'):
        stayIn -= 26
    lastLetter = chr(stayIn)
    cipher += lastLetter
else:
    cipher += i

如果您不想为每个循环打印一次结果，请将其移出循环。

Answer 2

要解决打印问题，您有：

def caesar_shift(text, shift):
    cipher = ""
    for i in text:
        ...

        print("Your ciphertext is: ", cipher)

    return cipher

caesar_shift(text, shift)

但你应该有

def caesar_shift(text, shift):
    cipher = ""
    for i in text:
        ...

    print("Your ciphertext is: ", cipher)

    return cipher

caesar_shift(text, shift)

或者更好

def caesar_shift(text, shift):
    cipher = ""
    for i in text:
        ...

    return cipher

print("Your ciphertext is: ", caesar_shift(text, shift))