在pygame中如何在同一屏幕上显示两个不同的动画

import pygame
pygame.init()

screen_width = 800
screen_height = 600
screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption("Animation Demo")

class Animation(pygame.sprite.Sprite):
    def __init__(self, x, y, images):
        super().__init__()
        self.images = images
        self.image = self.images[0]
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y
        self.current_frame = 0
        self.animation_speed = 10

    def update(self):
        self.current_frame = (self.current_frame + 1) % len(self.images)
        self.image = self.images[self.current_frame]

# 加载第一个动画帧图像
animation1_images = [pygame.image.load("animation1_frame1.png"), pygame.image.load("animation1_frame2.png"), pygame.image.load("animation1_frame3.png")]
animation1 = Animation(100, 100, animation1_images)

# 加载第二个动画帧图像
animation2_images = [pygame.image.load("animation2_frame1.png"), pygame.image.load("animation2_frame2.png"), pygame.image.load("animation2_frame3.png")]
animation2 = Animation(400, 200, animation2_images)

# 创建精灵组
all_sprites = pygame.sprite.Group()
all_sprites.add(animation1, animation2)

running = True
clock = pygame.time.Clock()

while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    all_sprites.update()

    screen.fill((255, 255, 255))  # 清屏
    all_sprites.draw(screen)  # 绘制所有精灵
    pygame.display.flip()  # 更新屏幕显示

    clock.tick(30)  # 控制帧率

pygame.quit()