title: PyQt - running a loop inside GUI
body: <p>I've got a Python code with some while loop inside, but I don't know how to make it work with my PyQt GUI - I can only run the Qt window or that loop (but then windows doesn't show).
  Is there any solution to this?
  I read about some QThreads or QTimers, but I don't have any idea how to use it.</p>