QtGui in background or separate thread


I have a python program that does some signal processing on packets
collected with the USRP and flowgraph. Inside the constructor of my
python class, I create an instance of mytop-block object. I’m trying to
use the QtGui sink to display the spectrum while the processing is going
on. My constructor to my python class looks like:

def init(self, **kwargs):
internal variables …
self._tb= top_block_ctor( **args )

My problem is the blocking that occurs with the qapp.exec_(). If I
remove that line in my constructor, then my processing works fine
(without the display). If I leave that line, then my spectrum display
works, but I don’t start the processing until I close the display. I
know that this is what the ‘blocking’ should do.

However, I would like it to not block or somehow run in another thread
so that the display is “live” while the processing is going on.

Is there a way to do this? I could not fine any examples on-line.