Qt for Python and PyQt5 have almost exactly the same API, to the point where it took me 30 min to migrate my 15kLoC project [1] from the latter to the former, mostly by changing a few imports. Maybe you meant something else?
Had a very similar experience a few years back migrating from PySide to PyQt when PySide wasn't able to keep up with Qt. Fixing the imports took minutes and we were off to the races.
hmm, then Pyside2 API must have changed significantly. I only used Pyside 1.