函数外的布尔值不会改变

Question

我正在学习 Python，但无法让我的 bool 在我的 replay 函数中从“True”变为“False”。我搜索了 Whosebug，但找不到答案。

我试过 canPlay = False 和 canPlay = not canPlay。但那是行不通的。

有什么建议吗？

import random
from random import randint

# welcome message
print("Welcome to the number guessing game!")

# get the random seed
seedValue = input("Enter random seed: ")
random.seed(seedValue)
canPlay = True

def play():

    randomNumber = randint(1, 100)
    numberOfGuesses = 1
    guessValue = ""

    while guessValue != randomNumber:

        # prompt the user for a guess
        guessValue = int(input("\nPlease enter a guess: "))

        # provide higher/lower hint
        if guessValue == randomNumber:
            print(f"Congratulations. You guessed it!\nIt took you {numberOfGuesses} guesses.")
        elif guessValue > randomNumber:
            print("Lower")
        else:
            print("Higher")

        # increment the count
        numberOfGuesses += 1

def replay():
    
    playAgain = input("\nWould you like to play again (yes/no)? ")

    if playAgain == "no":
        canPlay = False # not changing values
        canPlay = not canPlay # this doesn't work either
        print("Thank you. Goodbye.")

while canPlay == True:
    play()
    replay()

Answer 1

在 reply() 函数中使用 global 关键字，您可以更改全局命名空间中 canPlay 变量的值，然后在 while 语句 while canPlay == True::

def replay():
    global canPlay  # <------------------ Here

    playAgain = input("\nWould you like to play again (yes/no)? ")

    if playAgain == "no":
        canPlay = False # not changing values
        canPlay = not canPlay # this doesn't work either
        print("Thank you. Goodbye.")

如果不插入该行，canPlay 将是 reply() 函数的局部变量，因此它不能更改全局变量或被 [=17 之外的其他语句访问=]函数。

函数外的布尔值不会改变

Boolean value outside the function doesn't get changed

python

scope

python-3.x