在 Python 中更新函數內的局部變量

Question

我正在學習 python 並即將完成一個程序，在兩個玩家之間運行三輪石頭剪刀布游戲，並在每輪結束時更新玩家分數並將其顯示在屏幕上：

import random
"""This program plays a game of Rock, Paper, Scissors between two Players,
and reports both Player's scores each round."""

moves = ['rock', 'paper', 'scissors']

"""#!/usr/bin/env python3
import random
"""This program plays a game of Rock, Paper, Scissors between two Players,
and reports both Player's scores each round."""

moves = ['rock', 'paper', 'scissors']

"""The Player class is the parent class for all of the Players
in this game"""


class Player:
    def move(self):
        return 'rock'

    def learn(self, my_move, their_move):
        pass


def beats(one, two):
    return ((one == 'rock' and two == 'scissors') or
            (one == 'scissors' and two == 'paper') or
            (one == 'paper' and two == 'rock'))


class RandomPlayer(Player):
    def move(self):
        return random.choice(moves)

class Game:

    def __init__(self, p1, p2):
        self.p1 = p1
        self.p2 = p2

    def keep_p1_score(self, p1_Score):
        return p1_Score

    def play_round(self):
        move1 = self.p1.move()
        move2 = self.p2.move()
        p1_Score = 0
        p2_Score = 0
        print(f"Player One played: {move1}  Player Two played: {move2}")
        if beats(move1, move2) == True:
            print('**Player One wins**')
            p1_Score += 1
        elif beats(move2, move1) == True:
            print('**Player Two wins**')
            p2_Score += 1
        else:
            print('**TIE**')
        print(f'Score: Player One: {p1_Score} Player Two: {p2_Score}')
        self.p1.learn(move1, move2)
        self.p2.learn(move2, move1)

    def play_game(self):
        print("Game start!")
        for round in range(3):
            print(f"Round {round + 1}:")
            self.play_round()
        print("Game over!")



if __name__ == '__main__':
    game = Game(RandomPlayer(), RandomPlayer())
    game.play_game()

問題是當我運行代碼時，它不會更新玩家分數。 正如您在輸出的這張圖片中看到的，即使玩家 2 贏得了第二輪和第三輪，他在第三輪結束時的得分仍然是 1 而不是 2。我知道這是因為對於內部 for 循環中play_round函數的每次迭代play_game函數p1_score和p2_score的值重置為零，但我不知道如何阻止這種情況發生。 任何建議將不勝感激。 程序輸出

Answer 1

問題是， p1_Score和p2_Score是局部變量play_round 。 所以每次你調用這個函數時，你都會得到這些變量的一個新實例。 此外，你總是設置

p1_Score = 0
p2_Score = 0

在play_round 。 因此，在函數結束時，任何分數都不會大於 1。

為了解決這個問題，使用self.p1_Score和self.p2_Score使這些變量成為實例變量，並將 0 初始化移動到游戲類的__init__函數中。 或者，將分數Player類的類變量。