如何显示屏幕并使其停留在pygame中？

import pygame
import sys

pygame.init()
screen = pygame.display.set_mode((800, 600))

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

pygame.draw.rect(screen, (255, 0, 0), (100, 100, 200, 150))

pygame.display.flip()

import pygame
import sys

pygame.init()
screen = pygame.display.set_mode((800, 600))

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

    pygame.draw.rect(screen, (255, 0, 0), (100, 100, 200, 150))
    pygame.display.flip()