import pygame, sys

pygame.init()
display = pygame.display.set_mode((300,300))

mySurface = pygame.Surface((50,50))
mySurface.fill((0,255,0))

mySurface2 = pygame.Surface((50,100))
mySurface2.fill((0,255,0))

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

    display.blit(mySurface, (50,50))
    display.blit(mySurface2, (50,150))
    pygame.display.update()