__set_name__ equivalent for instance

[Dieter Maurer]

Dom Grigonis wrote at 2023-11-15 18:44 +0200:
>So there is a method __set_name__ which is called on class creation.
>
>The functionality that I am interested in is not retrieving name, but the fact that it also receives `owner` argument.
>
>Thus, allowing simulation of bound class method.
>
>I was wandering if there is an equivalent functionality of attribute to receive `instance` argument on instance creation.

As PEP 487 describes, `__set_name__` essentially targets descriptors.
It is there to inform a descriptor about the name it is used for
in a class (and the class itself). There is no other (easy) way to allow
a descriptor to learn about this name.

If a descriptor is accessed via an instance, the descriptor (protocol)
methods get the instance as parameter.
Note that descriptors are stored in the class: they must not store
instance specific information in their attributes.
Therefore, a method informing an descriptor about instance creation
would not help: it cannot do anything with it.