2007-05-20
Properties relevant to finding what class supplies a method
For my own future reference if nothing else, here's some properties relevant to finding what superclass supplies a method:
On super()
objects, we have:
__self__ |
the object you are calling super() about,
ie the second argument. |
__self_class__ |
the actual class of said object; equivalent
to .__self__.__class__ but more convenient. |
__this_class__ |
the class that super() was invoked for,
ie its first argument; this is where you are right now in the
superclass hierarchy. |
(Because the MRO varies by class, you need both the real class of the object and the current class.)
Unbound methods from Python classes show up as type 'unbound method'
in repr()
, and have an im_class
attribute that points to their
class (and an im_func
attribute that points to the actual Python
function).
Some methods from builtin classes, such as object.__init__
, show up
as type 'slot wrapper'. These have an __objclass__
attribute that
points to their class.
Other methods from builtin classes, such as object.__new__
, show
up as type 'built-in method'. These have a __self__
attribute
that points to their class.
Fortunately you can tell the three types of objects apart based on what attribute they have, because nothing has more than one of them (so far; this is where I start to think that this is fishing in the implementation defined waters).