让我家$ChatGPT$写了个代码，还不能用，要安装pygame库

import pygame
import random

# 初始化游戏
pygame.init()

# 游戏窗口大小
width = 640
height = 480

# 定义颜色
black = pygame.Color(0, 0, 0)
white = pygame.Color(255, 255, 255)
red = pygame.Color(255, 0, 0)
green = pygame.Color(0, 255, 0)
blue = pygame.Color(0, 0, 255)

# 设置游戏窗口
window = pygame.display.set_mode((width, height))
pygame.display.set_caption("贪吃蛇游戏")

# 蛇的初始位置
snake_position = [100, 50]
# 蛇的初始长度和速度
snake_body = [[100, 50], [90, 50], [80, 50]]
speed = [10, 0]

# 食物的初始位置
food_position = [random.randrange(1, (width//10)) * 10, random.randrange(1, (height//10)) * 10]
food_spawned = True

# 判断游戏是否结束的标志
game_over = False

# 控制游戏循环的变量
clock = pygame.time.Clock()

# 定义字体
font = pygame.font.SysFont(None, 48)

# 显示得分
def show_score(score):
    score_text = font.render("Score: " + str(score), True, white)
    window.blit(score_text, [10, 10])

# 游戏主循环
while not game_over:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()

        # 控制蛇的方向
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                speed = [10, 0]
            if event.key == pygame.K_LEFT:
                speed = [-10, 0]
            if event.key == pygame.K_UP:
                speed = [0, -10]
            if event.key == pygame.K_DOWN:
                speed = [0, 10]

    # 移动蛇的身体
    snake_position[0] += speed[0]
    snake_position[1] += speed[1]

    # 判断蛇是否吃到食物
    snake_body.insert(0, list(snake_position))
    if snake_position[0] == food_position[0] and snake_position[1] == food_position[1]:
        food_spawned = False
    else:
        snake_body.pop()

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

    # 绘制游戏窗口
    window.fill(black)
    for pos in snake_body:
        pygame.draw.rect(window, green, pygame.Rect(pos[0], pos[1], 10, 10))

    pygame.draw.rect(window, blue, pygame.Rect(food_position[0], food_position[1], 10, 10))

    # 判断游戏结束条件
    if snake_position[0] < 0 or snake_position[0] > width-10 or snake_position[1] < 0 or snake_position[1] > height-10:
        game_over = True
    for block in snake_body[1:]:
        if snake_position[0] == block[0] and snake_position[1] == block[1]:
            game_over = True

    # 显示得分
    show_score(len(snake_body)-3)

    # 更新游戏窗口
    pygame.display.update()

    # 控制游戏帧率
    clock.tick(20)