title: How to execute a method automatically after entering Qt event loop?
body: <p>I would like to execute a method which can only be called once my <code>QApplication</code> is displayed, i.e. when it has entered its main event loop <code>exec_()</code>. I'm new to Qt4 (using PyQt4): i was hoping to have a <code>on_start()</code>-like callback, but didn't find one.
  Do i need to create a thread or a timer? Or is there some callback included in the API already?</p>