帮我写个可运行的贪吃蛇python代码

以下是一个简单的贪吃蛇Python代码，可在Python 3中运行：

import pygame
import random

# 初始化pygame
pygame.init()

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

# 定义窗口大小
WINDOW_WIDTH = 400
WINDOW_HEIGHT = 400

# 创建窗口
window = pygame.display.set_mode((WINDOW_WIDTH, WINDOW_HEIGHT))
pygame.display.set_caption('贪吃蛇')

# 设置帧率
clock = pygame.time.Clock()
FPS = 10

# 定义贪吃蛇和食物
snake_pos = [100, 50]
snake_body = [[100, 50], [90, 50], [80, 50]]
food_pos = [random.randrange(1, (WINDOW_WIDTH//10)) * 10, random.randrange(1, (WINDOW_HEIGHT//10)) * 10]
food_spawn = True

# 定义方向
direction = 'RIGHT'
change_to = direction

# 定义字体
font_style = pygame.font.SysFont(None, 30)


def message(msg, color):
    """
    显示消息
    """
    mesg = font_style.render(msg, True, color)
    window.blit(mesg, [WINDOW_WIDTH/6, WINDOW_HEIGHT/3])


def game_over():
    """
    游戏结束
    """
    message('你输了，再试一次吧', RED)
    pygame.display.update()
    pygame.time.delay(2000)
    game_loop()


def draw_snake(snake_body):
    """
    绘制贪吃蛇
    """
    for pos in snake_body:
        pygame.draw.rect(window, GREEN, pygame.Rect(
            pos[0], pos[1], 10, 10))


def draw_food(food_pos):
    """
    绘制食物
    """
    pygame.draw.rect(window, RED, pygame.Rect(
        food_pos[0], food_pos[1], 10, 10))


def game_loop():
    """
    游戏循环
    """
    # 定义全局变量
    global direction, change_to, snake_pos, snake_body, food_pos, food_spawn

    # 游戏循环标志
    game_exit = False

    while not game_exit:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game_exit = True
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP and direction != 'DOWN':
                    change_to = 'UP'
                elif event.key == pygame.K_DOWN and direction != 'UP':
                    change_to = 'DOWN'
                elif event.key == pygame.K_LEFT and direction != 'RIGHT':
                    change_to = 'LEFT'
                elif event.key == pygame.K_RIGHT and direction != 'LEFT':
                    change_to = 'RIGHT'

        # 改变方向
        direction = change_to

        # 移动贪吃蛇
        if direction == 'UP':
            snake_pos[1] -= 10
        elif direction == 'DOWN':
            snake_pos[1] += 10
        elif direction == 'LEFT':
            snake_pos[0] -= 10
        elif direction == 'RIGHT':
            snake_pos[0] += 10

        # 增加贪吃蛇长度
        snake_body.insert(0, list(snake_pos))
        if snake_pos == food_pos:
            food_spawn = False
        else:
            snake_body.pop()

        # 生成食物
        if not food_spawn:
            food_pos = [random.randrange(
                1, (WINDOW_WIDTH//10)) * 10, random.randrange(1, (WINDOW_HEIGHT//10)) * 10]
        food_spawn = True

        # 绘制游戏界面
        window.fill(BLACK)
        draw_snake(snake_body)
        draw_food(food_pos)
        pygame.display.update()

        # 碰撞检测
        if snake_pos[0] < 0 or snake_pos[0] > WINDOW_WIDTH-10:
            game_over()
        elif snake_pos[1] < 0 or snake_pos[1] > WINDOW_HEIGHT-10:
            game_over()
        for block in snake_body[1:]:
            if snake_pos == block:
                game_over()

        # 设置帧率
        clock.tick(FPS)

    # 关闭pygame
    pygame.quit()
    quit()


# 开始游戏循环
game_loop()

运行代码后，会弹出一个窗口，贪吃蛇会自动移动，你需要控制贪吃蛇的方向，让它吃到食物，不要碰到墙壁或自己的身体，否则游戏失败。