使成排的精灵在pygame中重新出现在屏幕顶部

import pygame
import random

# 初始化pygame
pygame.init()

# 定义屏幕大小
screen_width = 800
screen_height = 600

# 创建屏幕对象
screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption("Sprite Reappear Example")

# 定义精灵类
class Sprite(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.image.fill((255, 0, 0))
        self.rect = self.image.get_rect()
        self.rect.x = random.randint(0, screen_width - self.rect.width)
        self.rect.y = random.randint(-screen_height, 0)
        self.speed = random.randint(1, 5)

    def update(self):
        self.rect.y += self.speed
        if self.rect.y > screen_height:
            self.rect.y = random.randint(-screen_height, 0)

# 创建精灵组
sprite_group = pygame.sprite.Group()

# 创建精灵对象并添加到精灵组
for _ in range(10):
    sprite = Sprite()
    sprite_group.add(sprite)

# 游戏循环
running = True
while running:
    # 处理事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # 更新精灵位置
    sprite_group.update()

    # 绘制背景
    screen.fill((255, 255, 255))

    # 绘制精灵
    sprite_group.draw(screen)

    # 更新屏幕显示
    pygame.display.flip()

# 退出游戏
pygame.quit()