title: python: kivy app not closing
body: <p>my kivy simple hello world app is not closing I'm using raspberry pi B and I can't close it I must unplug my raspberry pi 5v adapter to close it</p>
  
  <p>I'm using rasbian jessie
  this is the very simple code </p>
  
  <pre><code>import kivy
  from kivy.app import App
  from kivy.uix.label import Label
  
  class mamdouh(App):
      def build(self):
          return Label(text='mamdouh')
  
  if __name__=='__main__':
      mamdouh().run()
  </code></pre>