为什么我的朋友要来！=…'循环永不停止

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 wins\n")
    elif b == 2:
        print("P2 wins\n")
    elif b == 0:
        print("Tied\n")
    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，它不工作，并不断重复。我希望它重复，直到你写石头，布，或剪刀，当你写其中一个，退出while循环。你知道吗

Answer 1

其他答案都是正确的，但一种更为恶作剧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: "))

当您编写更复杂的程序时，这种方法可以很好地扩展：不是简单的列表，而是对参数使用函数调用，在输入验证函数中，对值执行任意数量的测试等。你知道吗

Answer 2

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

它说：p可能不是rock，paper，scissors。如果p等于这些单词中的任何一个，则整个谓词变成True，循环继续。在应用De Morgan transform时，您将or误认为and。无法退出循环，因为没有p可以同时等于rock、paper、和scissors。你知道吗

你想要的是

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

Answer 3

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: "))

如果一个条件是正确的，则退出白色循环。你知道吗