Pygame problem z poruszaniem obrazka.

WItam dlaczego nie moge poruszac obrazka?
``

import pygame
import sys

pygame.init()
screen = pygame.display.set_mode((1280, 720))

while True:
   mario_img = pygame.image.load('images/maryo.png')
   pressed = pygame.key.get_pressed()
   mario_img_rect = mario_img.get_rect()
   mario_img_rect.top = 10
   mario_img_rect.left = 10
   screen.blit(mario_img, mario_img_rect)

   pygame.display.flip()

   key_pressed = pygame.key.get_pressed()

   for event in pygame.event.get():

     if event.type == pygame.QUIT:
        pygame.quit()
        sys.exit()

 if pressed[pygame.K_s]:
     mario_img_rect.top -= 10