title: Kivy Python very basic Binding of Label Text
body: <p>I know this might be a very basic question, but after spending hours wrapping my head around it I still can't figure it out.</p>
  
  <p>I basically just want to bind the text of a label to a variable in the python code. lets call it <code>value</code>. however it should get updated everytime I run a loop <code>Clock.schedule_interval(RootWidget.update, 1.0/1.0)</code></p>
  
  <p>here is the python, simplified so its basically just the time, which is also printed just to see if it is actually working.</p>
  
  <pre><code>from kivy.app import App
  from kivy.uix.floatlayout import FloatLayout
  from kivy.uix.widget import Widget
  from kivy.clock import Clock
  from kivy.core.window import Window
  import time
  
  class RootWidget(FloatLayout):
  
  
      def update(self, *args):
          value = time.time()
          print value
          self.ids.value_label.text = str(value)
  
  
  class MainApp(App):
  
      def build(self):
          Window.size = (800, 480)
          r = RootWidget()
          Clock.schedule_interval(r.update, 1)
          print 'build running'
          return r
  
      def on_pause(self):
          return True
  
  if __name__ == '__main__':
      MainApp().run()
  </code></pre>
  
  <p>the kv file looks as such:</p>
  
  <pre><code>&lt;RootWidget&gt;:
  
  Label:
      id: value_label
      text:
      y: 20.0
      x: 0.0
      width: 100.0
      italic: False
      height: 50.0
  </code></pre>