写一个py贪吃蛇代码

编写一个简单的Python贪吃蛇游戏需要一些基本的图形库，比如`pygame`。以下是一个非常基础的版本，包含了游戏的基本框架：

import pygame
import random

# 初始化Pygame
pygame.init()

# 设置窗口大小
window_width = 400
window_height = 600
win = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("贪吃蛇")

snake_speed = 15
snake_direction = "right"

# 蛇的位置和长度
snake_pos = [[100, 100], [90, 100], [80, 100]]
snake_body = pygame.Surface((10, 10))  # 单元格尺寸
snake_color = (0, 255, 0)  # 绿色

food_pos = [random.randint(0, window_width - 10), random.randint(0, window_height - 10)]
food = pygame.Rect(food_pos[0] * 10, food_pos[1] * 10, 10, 10)
food_color = (255, 0, 0)  # 红色

def move_snake():
    global snake_direction
    if snake_direction == "up":
        snake_pos.insert(0, [snake_pos[0][0], snake_pos[0][1] - 10])
    elif snake_direction == "down":
        snake_pos.insert(0, [snake_pos[0][0], snake_pos[0][1] + 10])
    elif snake_direction == "left":
        snake_pos.insert(0, [snake_pos[0][0] - 10, snake_pos[0][1]])
    else:  # right
        snake_pos.insert(0, [snake_pos[0][0] + 10, snake_pos[0][1]])

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 and snake_direction != "down":
                snake_direction = "up"
            elif event.key == pygame.K_DOWN and snake_direction != "up":
                snake_direction = "down"
            elif event.key == pygame.K_LEFT and snake_direction != "right":
                snake_direction = "left"
            elif event.key == pygame.K_RIGHT and snake_direction != "left":
                snake_direction = "right"

    # 清除屏幕
    win.fill((0, 0, 0))

    # 移动并绘制蛇
    move_snake()
    for pos in snake_pos[:-1]:
        win.blit(snake_body, pos)

    # 判断蛇是否吃到食物
    if snake_pos[0] == food_pos:
        food_pos = [random.randint(0, window_width - 10), random.randint(0, window_height - 10)]
        snake_body.fill(snake_color)
        snake_len += 1
    else:
        snake_pos.pop()

    # 绘制食物
    win.blit(food, food_pos)

    # 更新屏幕
    pygame.display.update()

# 游戏结束
pygame.quit()

这个代码只是一个起点，如果你想让游戏更复杂，可以添加边界检查、碰撞检测、得分系统等功能。同时，为了提高可读性和维护性，建议将游戏逻辑拆分成单独的函数。