Due to the high degree of API compatibility, a lot of python and
python3 packages that use Qt don't care which particular Qt package
they get. They work equally well with pyqt4, pyqt5, and pyside.
I think that for these packages it would be worthwhile having a
generic dependency that could work with any of these packages.
Perhaps something like "Provides: python-qt-any" (and a corresponding
python 3 package).