title: How do I get a shape to loop across the screen in pygame
body: <pre><code>    import pygame
      pygame.init()
      screen = pygame.display.set_mode((1600,900))
      red=(255,0,0)
      blue=(0,0,204)
      white=(255,255,255)
      pygame.display.set_caption("Orbit")
      gameLoop=True 
      clock=pygame.time.Clock()
      while gameLoop:
  
        dy=10 
        dx=10
        x=600
        y=250
  
  
  
        for event in pygame.event.get():
  
            if (event.type==pygame.QUIT):
             gameLoop=False
        x=x +dx 
        y=y +dy
  
       screen.fill(white)
       pygame.draw.circle(screen,red,[800,450],50,0)
       pygame.draw.circle(screen,blue,[x,y],10,0)
       pygame.display.update()
       clock.tick(50)
      pygame.quit()
  </code></pre>
  
  <p>I wrote this code here that has two circles and I want to get one (the smaller one) to loop across the screen but for some reason its not moving, I have no idea what I'm doing wrong and I've read and googled some stuff that hasn't really helped me all that much.Any advice would be greatly appreciated , thank you for your time </p>