Pygame无法创建一个功能，可以让蛇吃食物，也可以关闭游戏，还可以增加蛇的大小

import pygame
import random

# 初始化Pygame
pygame.init()

# 设置窗口大小
width, height = 640, 480
screen = pygame.display.set_mode((width, height))
pygame.display.set_caption("Snake Game")

# 定义颜色
white = (255, 255, 255)
black = (0, 0, 0)
red = (255, 0, 0)

# 蛇和食物的初始位置
snake_pos = [[100, 50], [90, 50], [80, 50]]
food_pos = [random.randrange(1, (width//10)) * 10, random.randrange(1, (height//10)) * 10]
food_spawn = True

# 蛇的移动方向
direction = 'RIGHT'
change_to = direction

# 游戏速度
clock = pygame.time.Clock()
speed = 15

# 游戏主循环
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                change_to = 'UP'
            if event.key == pygame.K_DOWN:
                change_to = 'DOWN'
            if event.key == pygame.K_LEFT:
                change_to = 'LEFT'
            if event.key == pygame.K_RIGHT:
                change_to = 'RIGHT'

    # 确保蛇不会直接反向移动
    if change_to == 'UP' and not direction == 'DOWN':
        direction = 'UP'
    if change_to == 'DOWN' and not direction == 'UP':
        direction = 'DOWN'
    if change_to == 'LEFT' and not direction == 'RIGHT':
        direction = 'LEFT'
    if change_to == 'RIGHT' and not direction == 'LEFT':
        direction = 'RIGHT'

    # 移动蛇
    if direction == 'UP':
        snake_pos.insert(0, [snake_pos[0][0], snake_pos[0][1] - 10])
    if direction == 'DOWN':
        snake_pos.insert(0, [snake_pos[0][0], snake_pos[0][1] + 10])
    if direction == 'LEFT':
        snake_pos.insert(0, [snake_pos[0][0] - 10, snake_pos[0][1]])
    if direction == 'RIGHT':
        snake_pos.insert(0, [snake_pos[0][0] + 10, snake_pos[0][1]])

    # 检查蛇是否吃到食物
    if snake_pos[0] == food_pos:
        food_spawn = False
    else:
        snake_pos.pop()

    # 生成新的食物
    if not food_spawn:
        food_pos = [random.randrange(1, (width//10)) * 10, random.randrange(1, (height//10)) * 10]
    food_spawn = True

    # 碰撞检测
    if snake_pos[0][0] < 0 or snake_pos[0][0] >= width or snake_pos[0][1] < 0 or snake_pos[0][1] >= height:
        running = False
    for block in snake_pos[1:]:
        if snake_pos[0] == block:
            running = False

    # 绘制屏幕
    screen.fill(black)
    for pos in snake_pos:
        pygame.draw.rect(screen, white, pygame.Rect(pos[0], pos[1], 10, 10))
    pygame.draw.rect(screen, red, pygame.Rect(food_pos[0], food_pos[1], 10, 10))

    # 更新显示
    pygame.display.flip()

    # 控制游戏速度
    clock.tick(speed)

# 退出Pygame
pygame.quit()