This repo contains a series of examples that show how to implement basic widgets in PySide2.
I come here from time to time just to copy paste some boilerplate code before starting a new GUI, especially if it has been a while. 😁
They were testing using Python 2.7 and PySide2, mostly because they're aimed at Show TDs, Pipeline TDs, RND guys etc.. and currently Nuke 11 and Houdini 18 ship with PySide2, but not (yet) with Python3. Ah, yes, Maya 2018+ ships with PySide2 as well, but Maya.. who still writes tools for Maya? 😛
You can probably port them to use Qt.py in order to target PyQt4 & PyQt5 PySide & PySide2.