请用Python写一个贪吃蛇的游戏

以下是一个简单的贪吃蛇游戏的Python代码：

import pygame, random

# 初始化pygame
pygame.init()

# 设置游戏窗口大小
window_width = 500
window_height = 500
window = pygame.display.set_mode((window_width, window_height))

# 设置游戏标题
pygame.display.set_caption("贪吃蛇")

# 设置颜色
white = (255, 255, 255)
black = (0, 0, 0)
red = (255, 0, 0)

# 设置蛇的初始位置和长度
snake_x = 250
snake_y = 250
snake_size = 10
snake_speed = 10
snake_list = []
snake_length = 1

# 设置食物的位置
food_x = round(random.randrange(0, window_width - snake_size) / 10.0) * 10.0
food_y = round(random.randrange(0, window_height - snake_size) / 10.0) * 10.0

# 设置游戏循环标志
game_over = False

# 定义画蛇和画食物的函数
def draw_snake(snake_list):
    for x,y in snake_list:
        pygame.draw.rect(window, black, [x, y, snake_size, snake_size])

def draw_food(food_x, food_y):
    pygame.draw.rect(window, red, [food_x, food_y, snake_size, snake_size])

# 游戏循环
while not game_over:
    # 处理事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_over = True

    # 处理蛇的移动
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        snake_x -= snake_speed
    if keys[pygame.K_RIGHT]:
        snake_x += snake_speed
    if keys[pygame.K_UP]:
        snake_y -= snake_speed
    if keys[pygame.K_DOWN]:
        snake_y += snake_speed

    # 判断是否吃到食物
    if snake_x == food_x and snake_y == food_y:
        food_x = round(random.randrange(0, window_width - snake_size) / 10.0) * 10.0
        food_y = round(random.randrange(0, window_height - snake_size) / 10.0) * 10.0
        snake_length += 1

    # 更新蛇的位置列表
    snake_head = []
    snake_head.append(snake_x)
    snake_head.append(snake_y)
    snake_list.append(snake_head)
    if len(snake_list) > snake_length:
        del snake_list[0]

    # 判断是否碰到边界或自身
    if snake_x < 0 or snake_x > window_width - snake_size or snake_y < 0 or snake_y > window_height - snake_size:
        game_over = True
    for block in snake_list[:-1]:
        if block == snake_head:
            game_over = True

    # 绘制游戏界面
    window.fill(white)
    draw_snake(snake_list)
    draw_food(food_x, food_y)
    pygame.display.update()

# 退出pygame
pygame.quit()

这个代码实现了一个简单的贪吃蛇游戏，玩家可以通过方向键控制蛇的移动。游戏中包括蛇的移动、食物的生成、碰撞检测等基本功能。