具有多个字符串条件的while循环不能离开循环

Question

我是 Python 新手，我正在做一些项目来尝试学习它。我正在尝试制作一个石头剪刀布游戏来学习条件和循环。我的游戏中有一个名为“validator”的函数，它有一个带有 4 个字符串条件的 while 循环，但是当我尝试重新分配该变量以打破循环时，它仍然给我我内置的错误消息，说“请输入有效的响应”。

如何让 while 循环结束并返回变量 ans？

感谢您的帮助，

-乌鸦

# Rock Paper Scissors Game
import random

# Makes the Player Choose a Valid Answer Function
def validator():
    ans = input()
    while ans != "Rock" or "Paper" or "Scissors" or "QUIT":
        ans = input("Please enter a valid response: ")
    else:
        return ans

# Comp Choosers Function

def compcho():
    v = random.randrange(1, 3)
    if v == 1:
        return "Rock"
    if v == 2:
        return "Paper"
    if v == 3:
        return "Scissors"


# Win decider
def decider(man, pc):
    if man == pc:
        return "It's a tie! " + man + " to " + pc + "!"
    elif man != pc:
        if man == "Rock" and pc == "Scissors":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Rock" and pc == "Paper":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Scissors" and pc == "Rock":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Scissors" and pc == "Paper":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Paper" and pc == "Rock":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Paper" and pc == "Scissors":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Quit":
            print("Goodbye")
        else:
            print("Hmm I wasn't expecting " + man + ".")


# Program Start

print("Welcome to the Rock Paper Scissors Game!")
choice = "ham"
while choice != "Quit":

    # Chooser
    print("Please Enter Rock Paper Scissors or Quit")

    valans = validator()

    pcpick = compcho()

    print(decider(valans, pcpick))

Answer 1

您需要让其中一个函数返回值"Quit" 并使用它设置变量choice。我现在不在我的个人电脑前，所以我将主要用你的代码来回答。也许稍后我会回来编辑，把东西清理一下。

# Rock Paper Scissors Game
import random

# Makes the Player Choose a Valid Answer Function
def validator():
    ans = input()
    while ans != "Rock" or "Paper" or "Scissors" or "QUIT":
        ans = input("Please enter a valid response: ")
    else:
        return ans

# Comp Choosers Function

def compcho():
    v = random.randrange(1, 3)
    if v == 1:
        return "Rock"
    if v == 2:
        return "Paper"
    if v == 3:
        return "Scissors"


# Win decider
def decider(man, pc):
    if man == pc:
        return "It's a tie! " + man + " to " + pc + "!"
    elif man != pc:
        if man == "Rock" and pc == "Scissors":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Rock" and pc == "Paper":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Scissors" and pc == "Rock":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Scissors" and pc == "Paper":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Paper" and pc == "Rock":
            return "The player's choice of " + man + " beats the PC's choice of " + pc + "! Player Victory!"
        if man == "Paper" and pc == "Scissors":
            return "The player's choice of " + man + " loses to the PC's choice of " + pc + ". Player Defeat."
        if man == "Quit":
            print("Goodbye")
            # Must return a value here... 
            return "Quit"
        else:
            print("Hmm I wasn't expecting " + man + ".")
            # doesn't matter what gets returned here based on your other code so lets return "Keep Playing" for consistency 
            return "Keep Playing"


# Program Start

print("Welcome to the Rock Paper Scissors Game!")
choice = "ham"
while choice != "Quit":

    # Chooser
    print("Please Enter Rock Paper Scissors or Quit")

    valans = validator()

    pcpick = compcho()
 
    choice = decider(valans, pcpick) # see we set choice to the value of the decided function. 
    print(choice)
    # now the loop will have a condition that will cause it to exit.

Answer 2

你可以这样写你的条件（重复变量名并检查你的逻辑运算符）：

while ans != "Rock" and ans != "Paper" and ans != "Scissors" and ans != "QUIT":

或使用'in'：

while ans not in ["Rock","Paper","Scissors","QUIT"] :

Answer 3

欢迎来到 SO！写了一个格式良好的问题，做得很好。

您在这里遇到的问题与如何评估条件表达式有关。按照你现在的方式，Python 正在这样做：

while (ans != "Rock") or ("Paper") or ("Scissors") or ("QUIT")

在这种情况下，字符串“Paper”、“Scissors”和“Quit”本身的计算结果总是为真。你可以在这里看到：

>>> bool("Rock")
True

你想要的是：

while ans not in ["Rock", "Paper", "Scissors", "QUIT"]: