The pygame window opens and closes immediately

Question

The program works perfectly fine without trying to load the image. When trying to open it, the pygame window opens and instantly goes away. (I am completely new to programming)

    import pygame

    pygame.init()
    screen = pygame.display.set_mode((800, 600))
    background = pygame.image.load('togepi.png')

    pygame.display.set_caption("Mugiwara")

    #Game Loop

    running = True
    while running:
       screen.fill((0, 0, 0))
       screen.blit(background, (0,0))
       for event in pygame.event.get():
          if event.type == pygame.QUIT:
              running = False