Some notable Python GUI projects include the Blender 3D modeling software, the PyCharm integrated development environment, and the Dropbox desktop application.

Extensions are included for talking to both native Windows imaging functions and Python’s Tcl/Tk-backed Tkinter GUI package. Pillow is available through GitHub or the PyPI repository.

[Navin] has been hard at work producing a GUI which works with different micocontrollers. The idea is to make it even easier to develop projects by simplifying the feedback and control you can get … ...

Python is fine, there are lots of GUI bindings, but I cannot recommend any. Java + Swing gets very bad rep, but it's not too bad. I've done quite a bit of Swing and it's fairly straightforward.

Unfortunately, Micropython has historically lacked a decent high-level GUI library. Thankfully, that’s no longer the case, with [amirgon] porting LittlevGL to the platform.