title: Defining a function to add a black filled oval in Python with PyGraphics
body: <p>in python I am trying to create a picture with 20 by 20 pixels. Then define a function to add a black 16 by 16 oval at position (0, 0). But I am doing something wrong which I can't put my finger on. Please help. Thanks.</p>
  
  <pre><code>import media
  
  pic=media.create_picture(20,20)
  
  def copy_right(pic):
      media.add_oval_filled(pic,0,0,16,16,"black")
      return media.show(pic)
  
  copy_right(pic)
  </code></pre>