如何在pygame中删除不同的场景？

import pygame
from pygame.locals import *

# 场景管理器
class SceneManager:
    def __init__(self):
        self.scenes = []
        self.current_scene = None

    def add_scene(self, scene):
        self.scenes.append(scene)

    def switch_scene(self, scene):
        self.current_scene = scene

    def remove_scene(self, scene):
        if scene in self.scenes:
            self.scenes.remove(scene)
            del scene

# 场景基类
class Scene:
    def __init__(self):
        pass

    def draw(self, surface):
        pass

    def update(self):
        pass

    def handle_events(self, events):
        pass

# 场景A
class SceneA(Scene):
    def __init__(self):
        Scene.__init__(self)

    def draw(self, surface):
        surface.fill((255, 255, 255))
        pygame.draw.rect(surface, (0, 0, 255), (100, 100, 200, 200))

    def update(self):
        pass

    def handle_events(self, events):
        for event in events:
            if event.type == KEYDOWN and event.key == K_SPACE:
                scene_manager.remove_scene(scene_a)

# 场景B
class SceneB(Scene):
    def __init__(self):
        Scene.__init__(self)

    def draw(self, surface):
        surface.fill((255, 255, 255))
        pygame.draw.circle(surface, (255, 0, 0), (300, 300), 100)

    def update(self):
        pass

    def handle_events(self, events):
        for event in events:
            if event.type == KEYDOWN and event.key == K_SPACE:
                scene_manager.remove_scene(scene_b)

# 初始化pygame和场景管理器
pygame.init()
scene_manager = SceneManager()

# 创建场景对象
scene_a = SceneA()
scene_b = SceneB()

# 添加场景到场景管理器
scene_manager.add_scene(scene_a)
scene_manager.add_scene(scene_b)

# 初始时显示场景A
scene_manager.switch_scene(scene_a)

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

    scene_manager.current_scene.handle_events(pygame.event.get())
    scene_manager.current_scene.update()

    # 绘制当前场景
    scene_manager.current_scene.draw(screen)

    pygame.display.flip()

pygame.quit()