My application consists of looking into a live feed from a spectroscope (optical instrument) and extracting frames from it. Clicking a point in the feed launches a new Frame where the image is analysed. Each frame handles a single panel.
The action of creating  a new frame is very easy for a programmer to do (immediate showing and focus capture, discrete objects, no complex layout management, easy meaning for close button). 
I now want a design that works in a single window. What is the easiest design pattern that replaces the practice of creating new frames? It should offer the same advantages (see previous paragraph) as far as possible. I am thinking of using tabs to manage the panels as they can capture focus, hide/show panels, destroy themselves elegantly etc.
I would put your feed inside a sizer with space for two elements. Have the feed expand to fill your window unless the second space in the sizer is available. Then, when you click the feed, add a panel with the detailed information to the empty part of the sizer.
You can add a close button which would simply close and remove the panel in the same way as your currently do.
Design substitute to popping up new frames on each click in WxPython