请帮我完成一个贪吃蛇的小程序游戏代码

好的，以下是一个简单的贪吃蛇小游戏的代码，使用Python语言实现：

import pygame
import random

# 初始化
pygame.init()

# 窗口大小
window_width = 800
window_height = 600

# 创建窗口
window = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("贪吃蛇小游戏")

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

# 定义字体
font = pygame.font.SysFont(None, 25)

# 定义游戏速度
clock = pygame.time.Clock()
fps = 10

# 定义蛇的初始位置
block_size = 10
snake_list = []
snake_length = 1

# 定义食物的位置
food_x = round(random.randrange(0, window_width - block_size) / 10.0) * 10.0
food_y = round(random.randrange(0, window_height - block_size) / 10.0) * 10.0

# 定义蛇的方向
direction = "right"

# 游戏结束函数
def game_over():
    message("游戏结束，按Q退出或按C重新开始", red)
    pygame.display.update()

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_q:
                    pygame.quit()
                    quit()
                if event.key == pygame.K_c:
                    game_loop()

# 定义显示文字的函数
def message(msg, color):
    screen_text = font.render(msg, True, color)
    window.blit(screen_text, [window_width / 6, window_height / 3])

# 游戏主循环
def game_loop():
    global direction

    game_exit = False
    game_over_flag = False

    # 蛇的初始位置
    lead_x = window_width / 2
    lead_y = window_height / 2
    lead_x_change = 10
    lead_y_change = 0

    while not game_exit:

        while game_over_flag == True:
            game_over()

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                game_exit = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT and direction != "right":
                    direction = "left"
                    lead_x_change = -block_size
                    lead_y_change = 0
                elif event.key == pygame.K_RIGHT and direction != "left":
                    direction = "right"
                    lead_x_change = block_size
                    lead_y_change = 0
                elif event.key == pygame.K_UP and direction != "down":
                    direction = "up"
                    lead_y_change = -block_size
                    lead_x_change = 0
                elif event.key == pygame.K_DOWN and direction != "up":
                    direction = "down"
                    lead_y_change = block_size
                    lead_x_change = 0

        # 判断蛇是否撞墙
        if lead_x >= window_width or lead_x < 0 or lead_y >= window_height or lead_y < 0:
            game_over_flag = True

        # 更新蛇的位置
        lead_x += lead_x_change
        lead_y += lead_y_change

        # 填充窗口背景色
        window.fill(white)

        # 绘制食物
        pygame.draw.rect(window, green, [food_x, food_y, block_size, block_size])

        # 绘制蛇的身体
        snake_head = []
        snake_head.append(lead_x)
        snake_head.append(lead_y)
        snake_list.append(snake_head)

        if len(snake_list) > snake_length:
            del snake_list[0]

        for segment in snake_list[:-1]:
            if segment == snake_head:
                game_over_flag = True

        for segment in snake_list:
            pygame.draw.rect(window, black, [segment[0], segment[1], block_size, block_size])

        # 判断蛇是否吃到食物
        if lead_x == food_x and lead_y == food_y:
            food_x = round(random.randrange(0, window_width - block_size) / 10.0) * 10.0
            food_y = round(random.randrange(0, window_height - block_size) / 10.0) * 10.0
            snake_length += 1

        # 更新窗口
        pygame.display.update()

        # 控制游戏速度
        clock.tick(fps)

    # 退出游戏
    pygame.quit()
    quit()

# 运行游戏
game_loop()

这段代码实现了一个基本的贪吃蛇小游戏，具体的玩法可以参考游戏内的提示。