多场比赛后节目没有退出？

Question

from random import random


# This function handles the number guessing and number formatting
def run_game():

    # rand is declared by grabbing a number between 0 and 1, multiplying it by 100, and rounds to nearest integer
    rand = round(random() * 100, 0)
    print("Guess the number [0 - 100]")
    guesses = 0

    while True:

        # Assigns the 'answer' variable by grabbing user input from console
        answer = input()

        # Checks if the input from the console is a number, and if not, asks the user to enter a valid number
        if answer.isdigit():
            n = int(answer)
            if n > int(rand):
                print("Number is less than " + str(n))
                guesses = guesses + 1
            elif n < int(rand):
                print("Number is greater than " + str(n))
                guesses = guesses + 1
            else:
                guesses = guesses + 1
                print("It took you " + str(guesses) + " guesses to guess the right number!")
                reply = play_again()
                if reply is False:
                    break
                else:
                    run_game()
        else:
            print("Please enter a number")


def play_again():
    while True:
        reply = input("Play again? (y/n)\n")
        if reply.lower() == "y":
            return True
        elif reply.lower() == "n":
            return False
        else:
            print("Enter 'y' or 'n'")


if __name__ == "__main__":
    run_game()

所以当我运行这个程序时，运行正常。一旦猜出数字，我可以输入y或n再次播放。如果我只玩了一次，它就可以了。但是如果我选择y并再次播放，那么在玩第二场比赛后输入n就什么都不做

Answer 1

你的主要问题是你正在使用递归来开始新游戏，但是在递归调用返回之后（假设确实如此），你只需继续进行原始游戏。

有几种方法可以解决这个问题。最简单的方法是更改​​处理检查用户选择再次播放的代码，以便始终break s：

if reply:
    run_game()
break

更好的方法是摆脱递归。有几种方法可以做到这一点。一个简单的想法是简单地重置适当的变量，并在用户想要再次玩游戏时继续使用游戏循环：

reply = play_again()
if reply:
    rand = round(random() * 100, 0)
    print("Guess the number [0 - 100]")
    guesses = 0
else:
    break

避免递归的另一种方法是添加另一个循环。以下是使用单独函数执行此操作的一种方法：

def run_game():
    rand = round(random() * 100, 0)
    print("Guess the number [0 - 100]")
    guesses = 0

    while True:
        answer = input()
        if answer.isdigit():
            n = int(answer)
            if n > int(rand):
                print("Number is less than " + str(n))
                guesses = guesses + 1
            elif n < int(rand):
                print("Number is greater than " + str(n))
                guesses = guesses + 1
            else:
                guesses = guesses + 1
                print("It took you " + str(guesses) + " guesses to guess the right number!")
                break # unconditionally break here!

def run_many_games():
    again = True
    while again:
        run_game()
        again = play_again()

您可能会注意到，我在上面的所有代码中都进行了更改，我测试的是play_again的返回值是True还是False。如果您已经有bool值，则无需进行额外的比较步骤。如果您正在测试if reply，请执行if not reply（或False。您也可以在while循环条件下执行此操作，就像我在上一个代码块中使用again一样。

Answer 2

这是解决这个问题的好方法。在你的代码中，你永远不会真正退出while循环，因为运行游戏永远不会退出，并且没有返回系统变量来破坏它。使用sys.exit（0）也有效，但这是一个习惯于进入这些类型程序的习惯。

from random import random


# This function handles the number guessing and number formatting
def run_game():

    # rand is declared by grabbing a number between 0 and 1, multiplying it by 100, and rounds to nearest integer
    rand = round(random() * 100, 0)
    print("Guess the number [0 - 100]")
    guesses = 0

    while True:
        answer = input()
        if type(answer) == int:
            n = int(answer)
            if n > int(rand):
                print("Number is less than " + str(n))
                guesses = guesses + 1
            elif n < int(rand):
                print("Number is greater than " + str(n))
                guesses = guesses + 1
            else:
                guesses = guesses + 1
                print("It took you " + str(guesses) + " guesses to guess the right number!")
                break
    reply = play_again()
    if reply:
        run_game()
    else:
        print 'Thank you for playing'

def play_again():
    while True:
        reply = raw_input("Play again? (y/n)\n")
        if reply.lower() == "y":
            return True
        elif reply.lower() == "n":
            return False
        else:
            print("Enter 'y' or 'n'")

if __name__ == "__main__":
    run_game()

Answer 3

发生这种情况的原因是因为run_game最终以递归方式调用自身。当用户选择再次播放时，它不是重新开始游戏，而是有效地创建了游戏的新实例。然后，当用户选择停止播放时，它返回旧会话而不是退出程序。

您甚至可以通过在选择再次播放之前记住解决方案，然后选择在第二次会话后不再播放来证明这一点。然后，您将再次播放上一个会话并输入您记住或记下的解决方案。

现在，您可以使用sys.exit()代替break来强制程序关闭来解决此问题，但这似乎不是一种好习惯。如果有人选择再次播放太多次，他们可能会导致程序耗尽堆栈空间并崩溃。相反，最好将这个支票移出run_game这样

if __name__ == "__main__":
  while True:
  run_game()
  if not play_again():
    break

并将run_game中的else块修改为此

else:
  guesses = guesses + 1
  print("It took you " + str(guesses) + " guesses to guess the right number!")
  break

Answer 4

根据用户输入返回True或False是没有意义的，你可以直接在那里工作。

import sys
from random import random


# This function handles the number guessing and number formatting
def run_game():

    # rand is declared by grabbing a number between 0 and 1, multiplying it by 100, and rounds to nearest integer
    rand = round(random() * 100, 0)
    print("Guess the number [0 - 100]")
    guesses = 0

    while True:

        # Assigns the 'answer' variable by grabbing user input from console
        answer = input()

        # Checks if the input from the console is a number, and if not, asks the user to enter a valid number
        if answer.isdigit():
            n = int(answer)
            if n > int(rand):
                print("Number is less than " + str(n))
                guesses = guesses + 1
            elif n < int(rand):
                print("Number is greater than " + str(n))
                guesses = guesses + 1
            else:
                guesses = guesses + 1
                print("It took you " + str(guesses) + " guesses to guess the right number!")
                play_again()
        else:
            print("Please enter a number")


def play_again():
    while True:
        reply = input("Play again? (y/n)\n")
        if reply.lower() == "y":
            run_game()
        elif reply.lower() == "n":
            sys.exit(0)
        else:
            print("Enter 'y' or 'n'")


if __name__ == "__main__":
    run_game()

这样代码更清晰，可以解决您的问题。当你可以直接做事时，传递“旗帜”毫无意义。 由于您的游戏从0到100，您还应该验证用户是否没有输入大于100的数字，因为低于0的数字不会通过isdigit检查。