在pygame -Python上删除图形而不覆盖以前的图形

import pygame

# 初始化pygame
pygame.init()

# 设置窗口尺寸
window_size = (800, 600)
window = pygame.display.set_mode(window_size)

# 设置画布尺寸
canvas_size = (800, 600)
canvas = pygame.Surface(canvas_size)

# 绘制图形
rect = pygame.Rect(100, 100, 200, 200)
pygame.draw.rect(canvas, (255, 0, 0), rect)

# 保存图形为Surface对象
surface = canvas.copy()

# 清除之前的图形
canvas.fill((0, 0, 0))

# 绘制新的图形
pygame.draw.circle(canvas, (0, 255, 0), (400, 300), 100)

# 将保存的图形绘制到画布上
canvas.blit(surface, (0, 0))

# 更新窗口显示
window.blit(canvas, (0, 0))
pygame.display.flip()

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

# 退出pygame
pygame.quit()