我需要帮助清除菜单时，我点击一个按钮，以移动到另一个屏幕在pygame，python

import pygame
import sys

# 初始化pygame
pygame.init()

# 设置屏幕大小
screen_width = 800
screen_height = 600
screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption("Menu")

# 创建按钮
button_width = 200
button_height = 50
button_color = (255, 0, 0)
button_rect = pygame.Rect((screen_width - button_width) // 2, (screen_height - button_height) // 2, button_width, button_height)

# 游戏主循环
while True:
    # 监听事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == pygame.MOUSEBUTTONDOWN:
            # 获取鼠标点击位置
            mouse_pos = pygame.mouse.get_pos()
            # 判断按钮点击
            if button_rect.collidepoint(mouse_pos):
                # 清除菜单
                screen.fill((0, 0, 0))
                # 切换屏幕
                # TODO: 在新屏幕上显示所需内容

    # 绘制按钮
    pygame.draw.rect(screen, button_color, button_rect)

    # 更新屏幕
    pygame.display.flip()