为什么我的'while p1 !=...'循环永远不会停止

Question

def outcome(p1, p2):
    x = ''
    if p1 == p2:
        x = 0
        return x
    elif p1 == "rock" and p2 == "scissors" or p1 == "scissors" and p2 == "paper" or p1 == "paper" and p2 == "rock":
        x = 1
        return x
    elif p2 == "rock" and p1 == "scissors" or p2 == "scissors" and p1 == "paper" or p2 == "paper" and p1 == "rock":
        x = 2
        return x
a = 0
while a == 1:
    p1 = str(input("P1 choose: "))
    while p1 != "rock" or  p1 != "paper" or p1 != "scissors":
        p1 = str(input("Please select rock/paper/scissors: "))
    p2 = str(input("P2 choose: "))
    while p2 != "rock" or  p2 != "paper" or p2 != "scissors":
        p2 = str(input("Please select rock/paper/scissors: "))
    b = outcome(p1, p2)
    if b == 1:
        print("P1 winsn")
    elif b == 2:
        print("P2 winsn")
    elif b == 0:
        print("Tiedn")
    pit = str(input("Another one? yes/no - "))
    if pit == "no":
        a = 0
        raise SystemExit(0)

这部分永远不会停止：

while p1 != "rock" or  p1 != "paper" or p1 != "scissors":
        p1 = str(input("Please select rock/paper/scissors: "))

这是一个石头剪刀布游戏，当我输入正确或错误时，它不起作用并不断重复。我希望它重复，直到你写石头、纸或剪刀，当你写其中一个时，退出 while 循环。

Answer 1

while p1 != "rock" or  p1 != "paper" or p1 != "scissors":
    p1 = str(input("Please select rock/paper/scissors: "))

它说：p可以是任何东西，除了rock，paper，scissors。如果p等于这些单词中的任何一个，则整个谓词变为True，并且循环继续。在应用德摩根变换时，您将or误认为and 。循环不能退出，因为没有p可以同时等于rock、paper和scissors。

你似乎想要的是

while True:
  word = input("Please select rock/paper/scissors: ")  # it's already a string.
  if word in ("rock", "paper", "scissors"):
    break

Answer 2

你应该重写你的条件：

while not (p1 == "rock" or p1 == "paper" or p1 == "scissors"):
    p1 = str(input("Please select rock/paper/scissors: "))

如果一个条件正确，则退出白环。

Answer 3

其他答案是正确的，但更pythonic的方法是列出可接受的输入(或元组(，然后检查响应是否在其中：

valids = ["rock", "paper", "scissors"]
while p1 not in valids:
    p1 = str(input("Please select rock / paper / scissors: "))

当你编写更复杂的程序时，这是一个很好的扩展：也许你对参数使用函数调用，而不是一个简单的列表，在你的输入验证函数中，你对值执行任意数量的测试，等等。