#A bouncing ballimport sys, pygame__author__ = {'name' : 'Hongten',       'mail' : 'hongtenzone@foxmail.com',       'QQ'  : '648719819',       'Version' : '1.0'}pygame.init()size = width, height = 600, 500speed = [1, 1]black = 249, 130, 57screen = pygame.display.set_mode(size)ball = pygame.image.load('c://py//ball.png')ballrect = ball.get_rect()while 1:  for event in pygame.event.get():    if event.type == pygame.QUIT:      sys.exit()  ballrect = ballrect.move(speed)  if ballrect.left < 0 or ballrect.right > width:    speed[0] = -speed[0]  if ballrect.top < 0 or ballrect.bottom > height:    speed[1] = - speed[1]  screen.fill(black)  screen.blit(ball, ballrect)  pygame.display.flip()