如何在Python中进行用户输入错误处理？

Question

我不知道为什么我以前从未想到过……但是我想知道是否存在一种更整洁，更短或更有效的错误处理用户输入的方式。例如，如果我要求用户输入“ hello”或“再见”，而他们又输入了其他内容，则我需要它告诉用户这是错误的，然后再次询问。

对于我曾经做过的所有编码，这就是我做过的方式（通常问题更好）：

choice = raw_input("hello, goodbye, hey, or laters? ") 

while choice not in ("hello","goodbye","hey","laters"):

   print "You typed something wrong!"

   choice = raw_input("hello,goodbye,hey,or laters? ")

是否有更聪明的方法？还是我应该坚持自己的经历？这是我用于编写的所有语言的方法。

Answer 1

对于更复杂的系统，您可以有效地编写自己的解析器。

def get_choice(choices):
  choice = ""
  while choice not in choices:
      choice = raw_input("Choose one of [%s]:" % ", ".join(choices))
  return choice

choice = get_choice(["hello", "goodbye", "hey", "laters"])

Answer 2

>>> possible = ["hello","goodbye","hey"]
>>> def ask():
...     choice = raw_input("hello,goodbye,hey,or laters? ")
...     if not choice in possible:
...         return ask()
...     return choice
... 
>>> ask()
hello,goodbye,hey,or laters? d
hello,goodbye,hey,or laters? d
hello,goodbye,hey,or laters? d
hello,goodbye,hey,or laters? hello
'hello'
>>> 

Answer 3

options = ["hello", "goodbye", "hey", "laters"]
while choice not in options:
    print "You typed something wrong!"

Answer 4

while True:
    choice = raw_input("hello, goodbye, hey, or laters? ")
    if choice in ("hello","goodbye","hey","laters"):
        break
    else:
        print "You typed something wrong!"