在pygame中如何让精灵发生碰撞？

import pygame
from pygame.locals import *

# 初始化pygame
pygame.init()

# 创建窗口
screen = pygame.display.set_mode((800, 600))

# 创建精灵类
class Sprite(pygame.sprite.Sprite):
    def __init__(self, x, y):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.image.fill((255, 0, 0))
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

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

# 创建精灵对象
sprite1 = Sprite(100, 100)
sprite2 = Sprite(200, 200)

# 将精灵对象添加到精灵组
sprite_group.add(sprite1, sprite2)

# 游戏主循环
running = True
while running:
    for event in pygame.event.get():
        if event.type == QUIT:
            running = False

    # 碰撞检测
    collision = pygame.sprite.spritecollide(sprite1, sprite_group, True)
    if collision:
        print("碰撞发生！")

    # 绘制精灵
    screen.fill((255, 255, 255))
    sprite_group.draw(screen)
    pygame.display.flip()

# 退出游戏
pygame.quit()