写一个简单的Python贪吃蛇代码

好的，以下是一个简单的Python贪吃蛇代码：

import pygame
import random

# 设置窗口大小
SCREEN_WIDTH = 480
SCREEN_HEIGHT = 480

# 设置蛇的大小和速度
SNAKE_SIZE = 20
SNAKE_SPEED = 20

# 定义颜色
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)

# 初始化pygame
pygame.init()

# 创建窗口
screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
pygame.display.set_caption("贪吃蛇")

# 定义蛇的初始位置
snake_x = SCREEN_WIDTH / 2
snake_y = SCREEN_HEIGHT / 2

# 定义蛇的初始长度和方向
snake_length = 1
snake_direction = "right"

# 定义食物的初始位置
food_x = random.randrange(0, SCREEN_WIDTH - SNAKE_SIZE, SNAKE_SIZE)
food_y = random.randrange(0, SCREEN_HEIGHT - SNAKE_SIZE, SNAKE_SIZE)

# 游戏循环
while True:
    # 处理退出事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()
    
    # 处理键盘事件
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT] and snake_direction != "right":
        snake_direction = "left"
    elif keys[pygame.K_RIGHT] and snake_direction != "left":
        snake_direction = "right"
    elif keys[pygame.K_UP] and snake_direction != "down":
        snake_direction = "up"
    elif keys[pygame.K_DOWN] and snake_direction != "up":
        snake_direction = "down"
    
    # 根据方向移动蛇的位置
    if snake_direction == "right":
        snake_x += SNAKE_SPEED
    elif snake_direction == "left":
        snake_x -= SNAKE_SPEED
    elif snake_direction == "up":
        snake_y -= SNAKE_SPEED
    elif snake_direction == "down":
        snake_y += SNAKE_SPEED
    
    # 判断是否吃到食物
    if snake_x == food_x and snake_y == food_y:
        snake_length += 1
        food_x = random.randrange(0, SCREEN_WIDTH - SNAKE_SIZE, SNAKE_SIZE)
        food_y = random.randrange(0, SCREEN_HEIGHT - SNAKE_SIZE, SNAKE_SIZE)
    
    # 绘制游戏界面
    screen.fill(BLACK)
    pygame.draw.rect(screen, GREEN, [food_x, food_y, SNAKE_SIZE, SNAKE_SIZE])
    snake_head = []
    snake_head.append(snake_x)
    snake_head.append(snake_y)
    snake_list = []
    snake_list.append(snake_head)
    if len(snake_list) > snake_length:
        del snake_list[0]
    for segment in snake_list:
        pygame.draw.rect(screen, WHITE, [segment[0], segment[1], SNAKE_SIZE, SNAKE_SIZE])
    
    # 刷新窗口
    pygame.display.update()

这是一个基本的贪吃蛇游戏代码，可以在pygame环境下运行。