PyQt4 allows one to bind an unbound signal defined a QObject subclass and bind it to an instance using __get__. This is needed to write decorators that take the unbound signal because one cannot write a decorator that takes a bound signal since 'self' is not defined at decoration time.
For example, this works in PyQt4:
From my reading, normal python usage lets you bind any method using __get__:
So __get__ is the normal way of binding something to an instance.