Why is a Pygame window not responding immediately after opening?

Question

Python

import pygame
import sys

W, H = 10, 20
TILE = 45
GAME_RES = W * TILE, H * TILE
FPS = 60
pygame.init()
game_sc = pygame.display.set_mode(GAME_RES)
clock = pygame.time.Clock()

run = True
while run:
    game_sc.fill(pygame.Color('black'))
for event in pygame.event.get():
    if event.type == pygame.QUIT:
        run = False

pygame.display.flip()
clock.tick(FPS)

This is my first experience in python, I decided to create a simple tetris, but I ran into a problem, the pygame window is not responding. Looked at other forums but nothing helped.
Code above