title: Normalize Function in Python
body: <p>I'm currently working on a paint program using python 2.7.5 and pygame.  I came across an error with the ellipse tool and asked a classmate for some help and he said I was missing a .normalize().  I added it in and my tool was fixed.  I'm currently just wondering what that function does.  Here's the code it is used in:</p>
  
  <pre><code>        if mb[0] == 1 and canvas.collidepoint(mx,my):
          screen.set_clip(canvas)
          if tool == "ellipse":
              screen.blit(copy,(0,0))
              radius = Rect(startx,starty,mx-startx,my-starty)    #Area Ellipse is being drawn
              radius.normalize()
          if radius.height&lt;sz2*2 or radius.width&lt;sz2*2:
              draw.ellipse(screen,(c),(radius))
          else:
              draw.ellipse(screen,(c),(radius), sz2)
          screen.set_clip(None)
  </code></pre>