QtPy is a compatibility layer which allows to use the code written for
PyQt5 with any python Qt binding: PyQt4, PyQt5, pyside or pyside2.
Main differences in PyQt5:
- all widget classes are now in QtWidgets package, not QtGui;
- QString obsoleted by unicode (sip API 2);
- changed the way of signals connection.
- rearranged code to reduce cyclic dependencies
- doCleanShutdown is separated in shutdown.py
- shared queues are separated in queues.py
- some default values were moved to defaults.py
- knownnodes partially moved to knownnodes.py
