### 贪吃蛇游戏的设计与实现 以下是基于 `pygame` 库的一个完整的贪吃蛇游戏代码示例。该代码实现了基本的游戏逻辑，包括蛇的移动、食物生成、碰撞检测以及分数计算等功能。 ```python import pygame import sys import random from pygame.locals import * # 初始化 Pygame 和常量定义 pygame.init() FPS = 10 SCREEN_WIDTH, SCREEN_HEIGHT = 640, 480 GRID_SIZE = 20 UP, DOWN, LEFT, RIGHT = 'up', 'down', 'left', 'right' # 颜色定义 WHITE = (255, 255, 255) BLACK = (0, 0, 0) GREEN = (0, 255, 0) RED = (255, 0, 0) # 屏幕初始化 screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT)) pygame.display.set_caption('Python贪吃蛇小游戏') clock = pygame.time.Clock() # 定义蛇类 class Snake: def __init__(self): self.body = [(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2)] self.direction = UP def move(self, food_pos): head_x, head_y = self.body[0] if self.direction == UP: new_head = (head_x, head_y - GRID_SIZE) elif self.direction == DOWN: new_head = (head_x, head_y + GRID_SIZE) elif self.direction == LEFT: new_head = (head_x - GRID_SIZE, head_y) elif self.direction == RIGHT: new_head = (head_x + GRID_SIZE, head_y) self.body.insert(0, new_head) if self.body[0] != food_pos: self.body.pop() def change_direction(self, direction): opposites = {UP: DOWN, DOWN: UP, LEFT: RIGHT, RIGHT: LEFT} if direction != opposites.get(self.direction): self.direction = direction # 定义食物类 class Food: def __init__(self): self.position = (random.randrange(0, SCREEN_WIDTH // GRID_SIZE) * GRID_SIZE, random.randrange(0, SCREEN_HEIGHT // GRID_SIZE) * GRID_SIZE) def generate_new_position(self): self.position = (random.randrange(0, SCREEN_WIDTH // GRID_SIZE) * GRID_SIZE, random.randrange(0, SCREEN_HEIGHT // GRID_SIZE) * GRID_SIZE) # 绘制网格上的物体 def draw_objects(snake_body, food_pos): screen.fill(WHITE) for segment in snake_body: pygame.draw.rect(screen, GREEN, (*segment, GRID_SIZE, GRID_SIZE)) pygame.draw.rect(screen, RED, (*food_pos, GRID_SIZE, GRID_SIZE)) # 显示分数 def show_score(score): font = pygame.font.Font(None, 36) score_text = font.render(f'Score: {score}', True, BLACK) screen.blit(score_text, (10, 10)) # 主循环 def main(): snake = Snake() food = Food() score = 0 while True: for event in pygame.event.get(): if event.type == QUIT: pygame.quit() sys.exit() elif event.type == KEYDOWN: if event.key == K_UP and snake.direction != DOWN: snake.change_direction(UP) elif event.key == K_DOWN and snake.direction != UP: snake.change_direction(DOWN) elif event.key == K_LEFT and snake.direction != RIGHT: snake.change_direction(LEFT) elif event.key == K_RIGHT and snake.direction != LEFT: snake.change_direction(RIGHT) snake.move(food.position) if snake.body[0] == food.position: food.generate_new_position() score += 1 if ( snake.body[0][0] < 0 or snake.body[0][0] >= SCREEN_WIDTH or snake.body[0][1] < 0 or snake.body[0][1] >= SCREEN_HEIGHT or any(segment == snake.body[0] for segment in snake.body[1:]) ): break draw_objects(snake.body, food.position) show_score(score) pygame.display.flip() clock.tick(FPS) if __name__ == '__main__': main() ``` #### 关键功能说明 1. **蛇的移动** 使用方向控制变量管理蛇头的方向变化，并在每次更新时将新位置插入到身体列表头部[^1]。 2. **食物生成** 当蛇吃到食物后，重新随机生成一个新的食物位置[^4]。 3. **边界和自撞检测** 如果蛇超出屏幕范围或者碰到自己的身体，则结束游戏。 4. **用户输入处理** 捕获键盘事件以更改蛇的运动方向，同时防止反向操作（例如向上时无法立即向下）[^2]。 ---