I recently started using Python again for a project requiring a nice UI with plotting. I chose GTK over QT as the base for simple practical reasons - it was easy to get basic matplotlib graphis working, and i didnt have time for long A/B compare. It has a decent wysiwyg UI layout tool Glade, however the online docs and tutorials are at least 5yr out of date and leave out lots of details.
My app has a bunch of sensors and effectors and needs to display values and graphs, and give user some simple controls. It also needs to run on the Raspberry Pi, with controls on a remote PC (Windows). The comms layer will be another writeup. Here I will just document getting the GUI framework functional. (details to follow)