PySide or PyQT?

So I recently signed up for a friendly little programming contest, and to finish I'm going to need to learn to write a GUI. Writing code in python, so the frameworks I am contemplating are PySide and PyQT. This will be the first time I've ever done a GUI so I don't really know what I'm looking for when comparing them, so I open up to the community for input. What do you guys think?