title: pygame circle animation
body: <p>I'm trying to make a circle animation and want it to bounce inside the window just for practice. I was told that <code>pygame.draw.rect</code> returns a <code>Rect</code> object, however, I made this little code to see if it worked, and it didn't. The circle didn't move downwards one pixel per iteration like expected. What might be the problem?</p>
  
  <pre><code>import pygame, sys
  from pygame.locals import *
  
  pygame.init()
  screen = pygame.display.set_mode((600, 500), 0, 32)
  mainClock = pygame.time.Clock()
  
  screen.lock()
  circleRect = pygame.draw.circle(screen, (255, 255, 255), (100, 200), 40)
  screen.unlock()
  
  while True:
      for event in pygame.event.get():
          if event.type == QUIT:
              pygame.quit()
              sys.exit()
  
      circleRect.top += 1
  
      pygame.display.update()
      mainClock.tick(40)
  </code></pre>