QtPy is a small abstraction layer that lets you write
applications using a single API call to either PyQt or
PySide. QtPy also provides a set of additional QWidgets. It
provides support for PyQt5, PyQt4 and PySide using the PyQt5
layout (where the QtGui module has been split into QtGui and
Basically, you write your code as if you were using PyQt5 but
import qt from QtPy instead of PyQt5.