Python实例题：人机对战初体验Python基于Pygame实现四子棋游戏

目录

Python实例题

题目

代码实现

实现原理

游戏逻辑：

AI 算法：

界面渲染：

关键代码解析

游戏棋盘渲染

AI 决策算法

胜利条件检查

使用说明

安装依赖：

运行游戏：

游戏操作：

扩展建议

增强 AI：

界面改进：

功能扩展：

性能优化：

Python实例题

题目

人机对战初体验Python基于Pygame实现四子棋游戏

代码实现

import pygame
import sys
import numpy as np
import randomclass ConnectFour:def __init__(self):# 游戏常量self.ROWS = 6self.COLUMNS = 7self.SQUARE_SIZE = 100self.WIDTH = self.COLUMNS * self.SQUARE_SIZEself.HEIGHT = (self.ROWS + 1) * self.SQUARE_SIZEself.SCREEN_SIZE = (self.WIDTH, self.HEIGHT)self.RADIUS = int(self.SQUARE_SIZE / 2 - 5)# 颜色定义self.BLUE = (0, 0, 255)self.BLACK = (0, 0, 0)self.RED = (255, 0, 0)self.YELLOW = (255, 255, 0)self.WHITE = (255, 255, 255)# 初始化游戏pygame.init()self.screen = pygame.display.set_mode(self.SCREEN_SIZE)pygame.display.set_caption("四子棋")self.font = pygame.font.SysFont("SimHei", 40)self.small_font = pygame.font.SysFont("SimHei", 24)# 游戏变量self.board = np.zeros((self.ROWS, self.COLUMNS))self.game_over = Falseself.turn = 1  # 1: 玩家1/人类, 2: 玩家2/AIself.player_mode = 1  # 1: 人机对战, 2: 双人对战self.winner = 0# 绘制初始界面self.draw_board()pygame.display.update()def draw_board(self):"""绘制游戏棋盘"""# 绘制背景self.screen.fill(self.BLUE)# 绘制标题区域title_rect = pygame.Rect(0, 0, self.WIDTH, self.SQUARE_SIZE)pygame.draw.rect(self.screen, self.BLACK, title_rect)# 显示标题和模式title_text = self.font.render("四子棋", True, self.WHITE)self.screen.blit(title_text, (self.WIDTH // 2 - title_text.get_width() // 2, 30))mode_text = self.small_font.render("模式: 人机对战" if self.player_mode == 1 else "模式: 双人对战", True, self.WHITE)self.screen.blit(mode_text, (20, 35))# 绘制切换模式按钮button_rect = pygame.Rect(self.WIDTH - 150, 25, 120, 50)pygame.draw.rect(self.screen, self.RED if self.player_mode == 1 else self.YELLOW, button_rect)button_text = self.small_font.render("切换双人" if self.player_mode == 1 else "切换人机", True, self.WHITE)self.screen.blit(button_text, (button_rect.centerx - button_text.get_width() // 2, button_rect.centery - button_text.get_height() // 2))# 绘制棋盘格子for c in range(self.COLUMNS):for r in range(self.ROWS):pygame.draw.rect(self.screen, self.BLACK, (c * self.SQUARE_SIZE, (r + 1) * self.SQUARE_SIZE, self.SQUARE_SIZE, self.SQUARE_SIZE))pygame.draw.circle(self.screen, self.WHITE, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), int((r + 1) * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)# 绘制当前棋子for c in range(self.COLUMNS):for r in range(self.ROWS):if self.board[r][c] == 1:pygame.draw.circle(self.screen, self.RED, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), self.HEIGHT - int(r * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)elif self.board[r][c] == 2:pygame.draw.circle(self.screen, self.YELLOW, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), self.HEIGHT - int(r * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)# 如果游戏结束，显示获胜信息if self.game_over:overlay = pygame.Surface(self.SCREEN_SIZE, pygame.SRCALPHA)overlay.fill((0, 0, 0, 180))self.screen.blit(overlay, (0, 0))winner_text = self.font.render(f"玩家 {'红方' if self.winner == 1 else '黄方'} 获胜!" if self.winner != 0 else "平局!", True, self.WHITE)self.screen.blit(winner_text, (self.WIDTH // 2 - winner_text.get_width() // 2, self.HEIGHT // 2 - 30))restart_text = self.font.render("按R键重新开始", True, self.WHITE)self.screen.blit(restart_text, (self.WIDTH // 2 - restart_text.get_width() // 2, self.HEIGHT // 2 + 30))def is_valid_location(self, col):"""检查指定列是否可以放置棋子"""return self.board[0][col] == 0def get_next_open_row(self, col):"""获取指定列中下一个可用的行"""for r in range(self.ROWS - 1, -1, -1):if self.board[r][col] == 0:return rdef drop_piece(self, row, col, player):"""在指定位置放置棋子"""self.board[row][col] = playerdef check_winning_move(self, player):"""检查玩家是否获胜"""# 检查水平方向for c in range(self.COLUMNS - 3):for r in range(self.ROWS):if (self.board[r][c] == player and self.board[r][c + 1] == player and self.board[r][c + 2] == player and self.board[r][c + 3] == player):return True# 检查垂直方向for c in range(self.COLUMNS):for r in range(self.ROWS - 3):if (self.board[r][c] == player and self.board[r + 1][c] == player and self.board[r + 2][c] == player and self.board[r + 3][c] == player):return True# 检查正对角线for c in range(self.COLUMNS - 3):for r in range(self.ROWS - 3):if (self.board[r][c] == player and self.board[r + 1][c + 1] == player and self.board[r + 2][c + 2] == player and self.board[r + 3][c + 3] == player):return True# 检查反对角线for c in range(self.COLUMNS - 3):for r in range(3, self.ROWS):if (self.board[r][c] == player and self.board[r - 1][c + 1] == player and self.board[r - 2][c + 2] == player and self.board[r - 3][c + 3] == player):return Truereturn Falsedef is_board_full(self):"""检查棋盘是否已满"""for c in range(self.COLUMNS):if self.is_valid_location(c):return Falsereturn Truedef evaluate_window(self, window, player):"""评估一个窗口(四个位置)的得分"""score = 0opponent = 1 if player == 2 else 2if window.count(player) == 4:score += 100elif window.count(player) == 3 and window.count(0) == 1:score += 10elif window.count(player) == 2 and window.count(0) == 2:score += 5if window.count(opponent) == 3 and window.count(0) == 1:score -= 80  # 阻止对手三连return scoredef score_position(self, player):"""评估整个棋盘的得分"""score = 0# 评估中心列center_array = [int(i) for i in list(self.board[:, self.COLUMNS // 2])]center_count = center_array.count(player)score += center_count * 3# 评估水平方向for r in range(self.ROWS):row_array = [int(i) for i in list(self.board[r, :])]for c in range(self.COLUMNS - 3):window = row_array[c:c + 4]score += self.evaluate_window(window, player)# 评估垂直方向for c in range(self.COLUMNS):col_array = [int(i) for i in list(self.board[:, c])]for r in range(self.ROWS - 3):window = col_array[r:r + 4]score += self.evaluate_window(window, player)# 评估正对角线for r in range(self.ROWS - 3):for c in range(self.COLUMNS - 3):window = [self.board[r + i][c + i] for i in range(4)]score += self.evaluate_window(window, player)# 评估反对角线for r in range(self.ROWS - 3):for c in range(self.COLUMNS - 3):window = [self.board[r + 3 - i][c + i] for i in range(4)]score += self.evaluate_window(window, player)return scoredef get_valid_locations(self):"""获取所有可用的列"""valid_locations = []for col in range(self.COLUMNS):if self.is_valid_location(col):valid_locations.append(col)return valid_locationsdef minimax(self, depth, maximizingPlayer, alpha, beta):"""使用Minimax算法和Alpha-Beta剪枝选择最佳移动"""valid_locations = self.get_valid_locations()is_terminal = self.is_board_full() or self.check_winning_move(1) or self.check_winning_move(2)if depth == 0 or is_terminal:if is_terminal:if self.check_winning_move(2):return (None, 10000000)elif self.check_winning_move(1):return (None, -10000000)else:  # 平局return (None, 0)else:  # 深度为0return (None, self.score_position(2))if maximizingPlayer:value = -float('inf')column = random.choice(valid_locations)for col in valid_locations:row = self.get_next_open_row(col)temp_board = self.board.copy()self.drop_piece(row, col, 2)new_score = self.minimax(depth - 1, False, alpha, beta)[1]self.board = temp_boardif new_score > value:value = new_scorecolumn = colalpha = max(alpha, value)if alpha >= beta:breakreturn column, valueelse:  # 最小化玩家value = float('inf')column = random.choice(valid_locations)for col in valid_locations:row = self.get_next_open_row(col)temp_board = self.board.copy()self.drop_piece(row, col, 1)new_score = self.minimax(depth - 1, True, alpha, beta)[1]self.board = temp_boardif new_score < value:value = new_scorecolumn = colbeta = min(beta, value)if alpha >= beta:breakreturn column, valuedef ai_move(self):"""AI移动逻辑"""if not self.game_over:# 使用minimax算法选择最佳列，深度为4col, _ = self.minimax(4, True, -float('inf'), float('inf'))if self.is_valid_location(col):pygame.time.wait(500)  # 让AI思考看起来更自然row = self.get_next_open_row(col)self.drop_piece(row, col, 2)if self.check_winning_move(2):self.game_over = Trueself.winner = 2elif self.is_board_full():self.game_over = Trueself.winner = 0self.turn = 1  # 回到玩家1self.draw_board()pygame.display.update()def restart_game(self):"""重新开始游戏"""self.board = np.zeros((self.ROWS, self.COLUMNS))self.game_over = Falseself.turn = 1self.winner = 0self.draw_board()pygame.display.update()def run(self):"""运行游戏主循环"""clock = pygame.time.Clock()while True:clock.tick(60)for event in pygame.event.get():if event.type == pygame.QUIT:pygame.quit()sys.exit()if event.type == pygame.KEYDOWN:if event.key == pygame.K_r and self.game_over:self.restart_game()if event.type == pygame.MOUSEBUTTONDOWN:# 检查是否点击了模式切换按钮button_rect = pygame.Rect(self.WIDTH - 150, 25, 120, 50)if button_rect.collidepoint(event.pos):self.player_mode = 2 if self.player_mode == 1 else 1self.restart_game()continue# 游戏未结束且轮到人类玩家if not self.game_over and (self.turn == 1 or self.player_mode == 2):# 获取鼠标位置pos_x = event.pos[0]col = int(pos_x // self.SQUARE_SIZE)# 检查列是否有效if self.is_valid_location(col):# 获取下一个可用行row = self.get_next_open_row(col)# 放置棋子player = self.turnself.drop_piece(row, col, player)# 检查是否获胜if self.check_winning_move(player):self.game_over = Trueself.winner = player# 检查是否平局elif self.is_board_full():self.game_over = Trueself.winner = 0# 切换玩家self.turn = 2 if self.turn == 1 else 1# 绘制棋盘self.draw_board()pygame.display.update()# AI移动（人机对战且轮到AI）if not self.game_over and self.turn == 2 and self.player_mode == 1:self.ai_move()if __name__ == "__main__":game = ConnectFour()game.run()    

实现原理

这个四子棋游戏基于以下核心技术实现：

• 游戏逻辑：

  • 使用 numpy 数组表示游戏棋盘
  • 实现棋子放置、胜利条件检查和棋盘状态评估
  • 支持人机对战和双人对战模式

• AI 算法：

  • 使用 Minimax 算法进行决策
  • 实现 Alpha-Beta 剪枝优化搜索效率
  • 设计评分函数评估棋盘状态

• 界面渲染：

  • 使用 Pygame 创建图形界面
  • 实现棋盘、棋子和交互元素的绘制
  • 添加游戏状态提示和模式切换功能

关键代码解析

游戏棋盘渲染

def draw_board(self):# 绘制背景和标题self.screen.fill(self.BLUE)title_rect = pygame.Rect(0, 0, self.WIDTH, self.SQUARE_SIZE)pygame.draw.rect(self.screen, self.BLACK, title_rect)# 绘制棋盘格子和棋子for c in range(self.COLUMNS):for r in range(self.ROWS):pygame.draw.rect(self.screen, self.BLACK, (c * self.SQUARE_SIZE, (r + 1) * self.SQUARE_SIZE, self.SQUARE_SIZE, self.SQUARE_SIZE))pygame.draw.circle(self.screen, self.WHITE, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), int((r + 1) * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)# 绘制当前棋子状态for c in range(self.COLUMNS):for r in range(self.ROWS):if self.board[r][c] == 1:pygame.draw.circle(self.screen, self.RED, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), self.HEIGHT - int(r * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)elif self.board[r][c] == 2:pygame.draw.circle(self.screen, self.YELLOW, (int(c * self.SQUARE_SIZE + self.SQUARE_SIZE / 2), self.HEIGHT - int(r * self.SQUARE_SIZE + self.SQUARE_SIZE / 2)), self.RADIUS)

AI 决策算法

def minimax(self, depth, maximizingPlayer, alpha, beta):valid_locations = self.get_valid_locations()is_terminal = self.is_board_full() or self.check_winning_move(1) or self.check_winning_move(2)if depth == 0 or is_terminal:if is_terminal:if self.check_winning_move(2):return (None, 10000000)elif self.check_winning_move(1):return (None, -10000000)else:return (None, 0)else:return (None, self.score_position(2))if maximizingPlayer:value = -float('inf')column = random.choice(valid_locations)for col in valid_locations:row = self.get_next_open_row(col)temp_board = self.board.copy()self.drop_piece(row, col, 2)new_score = self.minimax(depth - 1, False, alpha, beta)[1]self.board = temp_boardif new_score > value:value = new_scorecolumn = colalpha = max(alpha, value)if alpha >= beta:breakreturn column, valueelse:value = float('inf')column = random.choice(valid_locations)for col in valid_locations:row = self.get_next_open_row(col)temp_board = self.board.copy()self.drop_piece(row, col, 1)new_score = self.minimax(depth - 1, True, alpha, beta)[1]self.board = temp_boardif new_score < value:value = new_scorecolumn = colbeta = min(beta, value)if alpha >= beta:breakreturn column, value

胜利条件检查

def check_winning_move(self, player):# 检查水平方向for c in range(self.COLUMNS - 3):for r in range(self.ROWS):if (self.board[r][c] == player and self.board[r][c + 1] == player and self.board[r][c + 2] == player and self.board[r][c + 3] == player):return True# 检查垂直方向for c in range(self.COLUMNS):for r in range(self.ROWS - 3):if (self.board[r][c] == player and self.board[r + 1][c] == player and self.board[r + 2][c] == player and self.board[r + 3][c] == player):return True# 检查正对角线for c in range(self.COLUMNS - 3):for r in range(self.ROWS - 3):if (self.board[r][c] == player and self.board[r + 1][c + 1] == player and self.board[r + 2][c + 2] == player and self.board[r + 3][c + 3] == player):return True# 检查反对角线for c in range(self.COLUMNS - 3):for r in range(3, self.ROWS):if (self.board[r][c] == player and self.board[r - 1][c + 1] == player and self.board[r - 2][c + 2] == player and self.board[r - 3][c + 3] == player):return Truereturn False

使用说明

• 安装依赖：

pip install pygame numpy

• 运行游戏：

python connect_four.py

• 游戏操作：

  • 人机对战：红方 (玩家) vs 黄方 (AI)
  • 双人对战：红方 (玩家 1) vs 黄方 (玩家 2)
  • 点击顶部按钮切换游戏模式
  • 点击列顶部放置棋子
  • 游戏结束后按 R 键重新开始

扩展建议

• 增强 AI：

  • 优化评分函数，考虑更多策略因素
  • 增加难度级别选择
  • 实现蒙特卡洛树搜索算法

• 界面改进：

  • 添加动画效果（棋子下落、胜利高亮）
  • 设计更精美的 UI 元素
  • 支持全屏模式和窗口调整

• 功能扩展：

  • 实现游戏存档和回放功能
  • 添加音效和背景音乐
  • 支持局域网多人对战

• 性能优化：

  • 使用位运算优化棋盘表示
  • 实现多线程计算 AI 决策
  • 添加游戏状态缓存机制