Question

我正在尝试使编码选项起作用，以便如果用户在字符串中输入数字，它将以“请只写字母！”的形式答复。并提示用户。现在我遇到一个错误：

Traceback (most recent call last):
  File "/Users/myname/Desktop/proj01.py", line 16, in <module>
    c = c + 1
TypeError: can only concatenate str (not "int") to str

我的代码是这样的：

#User Greeting
greeting = print("Hello! Welcome to the Caesar Cipher!")

#List Command Options
prompt1 = input("Select a commend: \n'e' to encode,\n'd' to decode, or\n'q' to quit\n")
while prompt1 != ("e" or "d" or "q"):
    print("Invalid choice")
    prompt1 = input("Select a commend: \n'e' to encode,\n'd' to decode, or\n'q' to quit\n")

#Encoding Option
if prompt1 == "e":
    prompt2 = input("Please enter a lowercase word string to encode: ")
    c = 0
    for c in prompt2:
        if not c.isalpha():
          c = c + 1
          print("Letters only please!")
          prompt2 = input("Please enter a lowercase string to encode: ")
        elif c.isupper():
          print("No uppercase please!")
          prompt2 = input("Please enter a lowercase string to encode: ")
    prompt3 = int(input("Please enter a rotation number between 1-25: "))
    while prompt3 != range(1, 25):
          print("Out of range")
          prompt3 = input("Please enter a rotation number between 1-25: ")

#Quit Option
if prompt1 == "q":
  print("Goodbye! Come back soon!")

Answer 1

您可以通过使用字符串的isalpha方法来确认输入是字符串，如果字符串仅包含字母，则返回True，否则返回False。

prompt1 = input("Select a commend: \n'e' to encode,\n'd' to decode, or\n'q' to quit\n")
if not prompt1.isalpha():
    #prompt1 does not contain only letters, deal with it here.

在需要确认仅包含字母的字符串的任何地方使用isalpha。

如何允许用户仅输入字母？

1 个答案: