import pygame

pygame.init()
screen = pygame.display.set_mode([256,128])
screen.fill([0,0,0])
pygame.draw.rect(screen,(255,255,255),(0,0,128,128),0)
pygame.display.flip()

for j in range(0,256):
    pygame.draw.line(screen, [j,j,j], [128,128], [j,0], 1)
    pygame.display.flip()

raw_input("Press ENTER to close the graphics window")
pygame.quit()