请列举一些贪吃蛇的运行代码

以下是一些贪吃蛇的运行代码：

控制贪吃蛇的移动：

if direction == 'UP':
    snake_head[1] -= step
elif direction == 'DOWN':
    snake_head[1] += step
elif direction == 'LEFT':
    snake_head[0] -= step
elif direction == 'RIGHT':
    snake_head[0] += step

检测贪吃蛇是否撞墙或撞到自己：

if snake_head in snake_body[1:]:
    game_over = True
if snake_head[0] < 0 or snake_head[0] >= width or snake_head[1] < 0 or snake_head[1] >= height:
    game_over = True

增加贪吃蛇的长度：

if snake_head == food_position:
    snake_body.insert(0, list(snake_head))
    food_position = [random.randrange(1, width/step)*step, random.randrange(1, height/step)*step]
    score += 1

绘制贪吃蛇和食物：

for pos in snake_body:
    pygame.draw.rect(screen, blue, pygame.Rect(pos[0], pos[1], step, step))
pygame.draw.rect(screen, green, pygame.Rect(food_position[0], food_position[1], step, step))

更新游戏帧率：

clock.tick(10)

处理游戏结束事件：

if game_over:
    font = pygame.font.SysFont(None, 50)
    text = font.render("Game Over! Your score is " + str(score), True, red)
    screen.blit(text, (width/6, height/3))
    pygame.display.update()
    time.sleep(2)
    pygame.quit()
    sys.exit()