title: How to make click-through windows PyQt
body: <p>I would like to make a window in PyQt that you can click through; ie click on a window and the click is passed through so you can interact with whatever is behind it, while the window remains on top. An example of the effect I am trying to achieve is like the notifications on Ubuntu which appear in the top-right hand corner by default, which you can click through.</p>
  
  <p>I would like to be able to do this in PyQt ideally; if not, my platform is linux but windows solutions are also welcome! </p>
  
  <p>Cheers for the help in advance! I've been giving this a bit of thought and research, it would be great to be able to do this.</p>
  
  <p>EDIT: I am trying to make a window you can use like tracing paper for the window behind</p>