import pygame
import random
pygame.init()

screen = pygame.display.set_mode([500, 500])
RED = (255, 0, 0)
GREEN =(0,255, 0)
BLUE = (0,0,255)
x1 = 0
y1 = 0
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    pygame.draw.rect(screen,RED, (random.randint(0,500),0,x1,y1))
    y1+=1
    pygame.display.flip()
    
pygame.quit()