使用python与pygame，编写一个贪吃蛇游戏

好的，下面是一个简单的贪吃蛇游戏的代码示例：

import pygame
import random

# 定义颜色
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
RED = (255, 0, 0)

# 定义方向
UP = 0
DOWN = 1
LEFT = 2
RIGHT = 3

# 初始化pygame模块
pygame.init()

# 设置窗口大小和标题
screen_width = 500
screen_height = 500
screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption("贪吃蛇游戏")

# 设置时钟
clock = pygame.time.Clock()

# 加载字体
font = pygame.font.SysFont(None, 25)

# 定义贪吃蛇类
class Snake:
    def __init__(self):
        self.size = 3  # 初始长度
        self.direction = RIGHT  # 初始方向
        self.body = [(100, 100), (90, 100), (80, 100)]  # 初始坐标

    def move(self):
        if self.direction == UP:
            new_head = (self.body[0][0], self.body[0][1] - 10)
        elif self.direction == DOWN:
            new_head = (self.body[0][0], self.body[0][1] + 10)
        elif self.direction == LEFT:
            new_head = (self.body[0][0] - 10, self.body[0][1])
        elif self.direction == RIGHT:
            new_head = (self.body[0][0] + 10, self.body[0][1])

        self.body.insert(0, new_head)

        if len(self.body) > self.size:
            self.body.pop()

    def change_direction(self, direction):
        if direction == UP and self.direction != DOWN:
            self.direction = UP
        elif direction == DOWN and self.direction != UP:
            self.direction = DOWN
        elif direction == LEFT and self.direction != RIGHT:
            self.direction = LEFT
        elif direction == RIGHT and self.direction != LEFT:
            self.direction = RIGHT

    def draw(self):
        for x, y in self.body:
            pygame.draw.rect(screen, GREEN, [x, y, 10, 10])

# 定义食物类
class Food:
    def __init__(self):
        self.pos = (0, 0)
        self.color = RED
        self.randomize_pos()

    def randomize_pos(self):
        self.pos = (random.randint(0, screen_width - 10) // 10 * 10,
                    random.randint(0, screen_height - 10) // 10 * 10)

    def draw(self):
        pygame.draw.rect(screen, self.color, [self.pos[0], self.pos[1], 10, 10])

# 创建贪吃蛇和食物对象
snake = Snake()
food = Food()

# 游戏循环
game_over = False
while not game_over:
    # 事件循环
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_over = True
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                snake.change_direction(UP)
            elif event.key == pygame.K_DOWN:
                snake.change_direction(DOWN)
            elif event.key == pygame.K_LEFT:
                snake.change_direction(LEFT)
            elif event.key == pygame.K_RIGHT:
                snake.change_direction(RIGHT)

    # 移动贪吃蛇
    snake.move()

    # 判断是否吃到食物
    if snake.body[0] == food.pos:
        snake.size += 1
        food.randomize_pos()

    # 判断是否撞到墙或自己的身体
    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 \
       snake.body[0] in snake.body[1:]:
        game_over = True

    # 绘制屏幕
    screen.fill(BLACK)
    snake.draw()
    food.draw()

    # 绘制分数
    score_text = font.render("Score: {}".format(snake.size - 3), True, WHITE)
    screen.blit(score_text, [10, 10])

    # 刷新屏幕
    pygame.display.flip()

    # 控制帧率
    clock.tick(10)

# 退出游戏
pygame.quit()

这个示例代码使用了pygame模块来实现游戏的绘制和事件处理，同时定义了一个Snake类和一个Food类来管理贪吃蛇和食物的状态。在游戏循环中，每帧都会处理用户输入、移动贪吃蛇、判断是否吃到食物或撞到墙或身体、绘制屏幕和分数等操作。最后，在游戏结束时退出pygame模块。