Python 循环 - 有效输入答案

【问题标题】：Python Loop - Valid InputPython 循环 - 有效输入
【发布时间】：2019-10-18 12:54:27
【问题描述】：

所以我在代码开头询问用户是否想玩时遇到了一些问题。如果用户输入无效响应，我如何让它重播循环？

以下是我目前所拥有的，但我不知道从哪里开始

play = input('Would you like to play the Guess the Number Game [y|n]?')
while play == 'y':
     play = True
if play == 'n':
     print ("No worries... another time perhaps... :)")
     exit()
else:
     print ("Please enter either 'y' or 'n'.")

【问题讨论】：

Asking the user for input until they give a valid response的可能重复

标签： python loops if-statement while-loop numbers

【解决方案1】：

这也可以通过递归来完成：

def user_input():
    play = input('Would you like to play the Guess the Number Game [y|n]?')
    if play == 'y':
        print("Play Starting...")
        return True
    elif play == 'n':
        print("No worries... another time perhaps... :)")
        return False
    else:
        user_input()


user_input()

【讨论】：

【解决方案2】：

定义一个用于请求用户输入的递归函数，当输入无效时调用自身。

def playFunction():
    play = input('Would you like to play the Guess the Number Game [y|n]?')
    if play == 'y':
         play = True
    if play == 'n':
        play = False
        print ("No worries... another time perhaps... :)")
        return
    else:
         print ("Please enter either 'y' or 'n'.")
         playFunction()

【讨论】：

【解决方案3】：

我想这就是你想要的：

break_condition = True
while break_condition:
    play = input('Would you like to play the Guess the Number Game [y|n]?')
    if play == 'y':
        play = True
        break_condition = False

    elif play == 'n':
        print ("No worries... another time perhaps... :)")
        break_condition = False
    else:
        print ("Please enter either 'y' or 'n'.")

【讨论】：

【解决方案4】：

while True:
    play = input('Would you like to play the Guess the Number Game [y|n]?').lower()
    if play == 'n':
        print ("No worries... another time perhaps... :)")
        break
    elif play == 'y':
        #write your game code here 
    else:
        print ("Please enter either 'y' or 'n'.")

【讨论】：