Question

我正在尝试在python中重新启动我的程序，但是，由于某种原因，代码在while playagain循环中被捕获。它说“这不是一个有效的答案。请输入'是'或'否'。”当我输入yes，no或任何其他可接受的输入时。为什么这不起作用？

while True:
    playagain = input("Would you like to play again?")
    while playagain != "y" or playagain != "Y" or playagain != "Yes" or playagain != "yes" or playagain != "YES" or playagain != "n" or playagain != "N" or playagain != "No" or playagain != "no" or playagain != "NO":
         print("That was not a valid answer. Please enter 'yes' or 'no'.")
         playagain = input("Would you like to play again?")
    if playagain == "y" or playagain == "Y" or playagain == "Yes" or playagain == "yes" or playagain == "YES":
         break
    else:
         print("Thank you for playing MadLibs!")

Answer 1

您可以使用lower()函数和in运算符来清理代码。

您可以更改此代码：

playagain = input("Would you like to play again?").lower()
while playagain not in ['y', 'yes', 'n', 'no']:
     print("That was not a valid answer. Please enter 'yes' or 'no'.")
     playagain = input("Would you like to play again?").lower()

这样整个代码就是：

while True:
    playagain = input("Would you like to play again?").lower()
    while playagain not in ['y', 'yes', 'n', 'no']:
         print("That was not a valid answer. Please enter 'yes' or 'no'.")
         playagain = input("Would you like to play again?").lower()
    if playagain in ['n', 'no']:
         print("Thank you for playing MadLibs!")
         break

Answer 2

你想：

while playagain != "y" or playagain != "Y" or playagain != "Yes"

是：

while playagain != "y" and playagain != "Y" and playagain != "Yes"

Answer 3

你也可以这样做：

while True:
    valid_response = ["y","Yes","Y","No","n","N"]
    positive_response = ["y","Yes","Y"]
    playagain = input("Would you like to play again?")
    while playagain not in valid_response:
        print("That was not a valid answer. Please enter 'yes' or 'no'.")
        playagain = input("Would you like to play again?")
    if playagain in positive_response:
        printf("You chose to play again"):
        break
    else:
        print("Thank you for playing MadLibs!")
        break;

代码中的问题是，while循环中至少有一个句子总是为真。由于playagain不能同时为"Y"，"y"，"Yes"，"No"，"n"和"N" （对于循环中的条件为假）。

Python程序不会重新启动

3 个答案: