code: def code_toggle(start_show=False, message=None):
      
  
      
      html ='<script>\n'
      if message is None:
          message = u'The raw code for this jupyter notebook can be hidden for easier reading.'
      if start_show:
          html += u'code_show=true;\n'
      else:
          html += u'code_show=false;\n'
      html+='''function code_toggle() {
   if (code_show){
   $('div.input').show();
   } else {
   $('div.input').hide();
   }
   code_show = !code_show
  } 
  $( document ).ready(code_toggle);
  </script>
  '''
      html += message + ' To toggle on/off the raw code, click <a href="javascript:code_toggle()">here</a>.' 
      display(HTML(html))
docs: Toggling on and off code in a notebook. 
      :param start_show: Whether to display the code or not on first load (default is False).
      :type start_show: bool
      :param message: the message used to toggle display of the code.
      :type message: string
  
      The tip that this idea is
      based on is from Damian Kao (http://blog.nextgenetics.net/?e=102).