我在 while 循環中使用函數的程序不保留更新的值

Question

我正在為 class 創建一個撿起棍子的游戲。我們的目標是創建一個 function 循環運行游戲的其他 4 個函數。

main():
  while numb_sticks > 1:
    func1()
    func2()
    func3()
    func4()
  else:
    print("Player {} wins!")

我的問題是保留我從一個 function 更改到下一個的值。 我在我的函數之外聲明了 numb_sticks，還有起始玩家。

numb_sticks = 20
player = 1

我在整個函數中都有 print() 來跟蹤正在更改的值。 我已經確定，當 function 完成時，numb_stick 和 player 值將恢復到 function 之外的原始值。這實質上創建了一個無限循環，其中木棒的數量總是恢復到 20，而輪到始終是玩家 1。我是需要將這兩個變量用作我的函數的參數。 我不知道如何解決這個問題。 以下是我的全部代碼。 我在整個程序中添加了注釋來解釋我在做什么。

pick_up_sticks.py

import random

def not_quite_right(numb_sticks): #This function creates a chance to add sticks to the game.
    global sticks_added #Declaring variables global to be changed across program.
    global sticks_remaining
    print("Initial numb_sticks nqr:", numb_sticks) #Testing change.
    n = random.randint(1,10) #This and the next line set up the %30 chance for more sticks.
    if n > 7: 
        sticks_added = random.randint(1,4) #This sets up a random amount of sticks between 1-4 to be added.
        if numb_sticks + sticks_added <= 20: #Checks if cap is exceeded.
            numb_sticks += sticks_added #Adding sticks to pile.
            print(numb_sticks) #Testing change, will remove on final.
            return
        else:
            sticks_added = 20 - numb_sticks #This is a small work around if the sticks added would have been more than 20.
            numb_sticks = 20
            return
    else: #The following complets the 70% chance of no sticks being added.
        sticks_added = 0
        return
"""
---
"""
def take_sticks(player, numb_sticks):
    global sticks_taken #Setting variables as global for use across program.
    global sticks_remaining
    print("Initial numb_sticks ts:", numb_sticks) #Test before change.
    if numb_sticks > 1: #Checks if game is still going.
        sticks_taken = input("Player {}, choose how many sticks you would like to take: ".format(player)) #Lets player choose stick amount.
        try: #Next 4 lines check if the input is a number and restarts turn if it isn't.
            int(sticks_taken)
        except ValueError:
                print("Invalid input! Please type a number.")
                take_sticks(player, numb_sticks)
        sticks_taken = int(sticks_taken) #Sets input as integer.
        if sticks_taken <= 0 or sticks_taken >= 4: #Next 3 lines check if inputted number is legal move and restarts turn if it isn't.
            print("You can only take 1, 2, or 3 sticks.")
            take_sticks(player, numb_sticks)
        elif sticks_taken < 4 and sticks_taken > 0: #Determines legal move.
            numb_sticks -= sticks_taken #Sets sticks remaining by removing sticks taken from original 20 sticks.
            print("Numb_sticks:", numb_sticks) #Test change.
            if player == 1: #Next 5 lines changes players turn.
                player = 2
                print("Next turn is player", player,"'s turn.'") #Test player change.
                return
            else:
                player = 1
                return
            return
        else:
            return
    else:
        return
    
def display_board(numb_sticks): #This function states how many sticks there are at the start of the turn.
    print("There are", numb_sticks, " sticks on the board.")

def display_summary(player, sticks_taken, sticks_added, numb_sticks): #The following function simply displays the remaining sticks and the next players turn.
    print("Player", player,"took", sticks_taken, "sticks, pictsie added", sticks_added, "sticks back, leaving", numb_sticks, "sticks.")
            
def main(): #Creating a loop for the game.
    numb_sticks = 20 #Setting the number of sticks.
    player = 1 #Sets player 1 to start.
    while numb_sticks > 1:
        display_board(numb_sticks)
        take_sticks(player, numb_sticks)
        not_quite_right(numb_sticks)
        display_summary(player, sticks_taken, sticks_added, sticks_remaining)
    else:
        print("Player {} has won the game!".format(player)) #Declares a player the winner!

main() #Begins the game!

Answer 1

那么，您是否嘗試傳遞在 main() 中聲明為函數參數的全局值？ 這樣你的全局值總是與函數相關聯。

def main():
    numb_sticks = 20
    player = 1
    if numb_sticks > 1:
        func1(numb_sticks, player)
        func2(numb_sticks, player)
    else:
        print("Player {} wins!")

def func1(numb_sticks, player):

def func2(numb_sticks, player):

Answer 2

無限循環的原因是無論numb_sticks遞減還是遞增， numb_sticks都是一個臨時局部變量（好吧，它是一個參數，它也是一個臨時變量，就像局部變量一樣）。 一旦 function 到達該特定調用的末尾，臨時變量numb_sticks （及其遞減值或遞增值）就會消失。

有很多方法可以解決這個問題。

我通過以下更改擺脫了無限循環：

1. 修改了函數not_quite_right()和take_sticks()以便每次return都更改為return numb_sticks 。 這會將局部變量的（增加或減少的值）返回到調用 function 的調用點。

2. 接下來，我修改了main() function 中while循環的主體，如下所示：

    display_board(numb_sticks) numb_sticks = take_sticks(player, numb_sticks) numb_sticks = not_quite_right(numb_sticks) display_summary(player, sticks_taken, sticks_added, sticks_remaining)

游戲以大約 5 步結束。