Support for Qt Interfaces ========================= PyQt5 does not, generally, support defining a class that inherits from more than one Qt class. The exception is when inheriting from classes that Qt defines as *interfaces*, for example :class:`~PyQt5.QtGui.QTextObjectInterface`. A Qt interface is an abstract class contains only pure virtual methods and is used as a mixin with (normally) a :class:`~PyQt5.QtCore.QObject` sub-class. It is often used to define the interface that a plugin must implement. Note that PyQt5 does not need an equivalent of Qt's ``Q_INTERFACES`` macro in order to use an interface class. The ``textobject.py`` example includedd with PyQt5 demonstrates the use of an interface.