I want to do something like:

try:
    import QtPy
except ImportError:
    pass

and have this also catch the case where PyQt5 or PySide aren't installed. However, in those cases the exception is PythonQtError rather than ImportError. However, I can't catch PythonQtError because I can't do from qtpy import PythonQtError since QtPy won't import...

Since I don't watch to just catch Exception, could PythonQtError be made a subclass of ImportError?