Getting the name of an assignment

[BJörn Lindqvist]

On 23 Dec 2006 14:38:19 -0800, Adam Atlas <adam at atlas.st> wrote:
> Is it possible for an object, in its __init__ method, to find out if it
> is being assigned to a variable, and if so, what that variable's name
> is? I can think of some potentially ugly ways of finding out using
> sys._getframe, but if possible I'd prefer something less exotic.
> (Basically I have a class whose instances, upon being created, need a
> 'name' property, and if it's being assigned to a variable immediately,
> that variable's name would be the best value of 'name'; to make the
> code cleaner and less redundant, it would be best if it knew its own
> name upon creation, just like functions and classes do, without the
> code having to pass it its own name as a string.)

I guess you mean something like this:

>>> olle = Person()
>>> olle.name
"olle"

Instead of:

>>> olle = Person("olle")
>>> olle.name
"olle"

It is not possible without ugly hacks. What you could use instead is
some kind of registry approach:

reg = {}
class Person:
    def __init__(self, name):
        self.name = name
        reg[name] = self

>>> Person("olle")
>>> reg["olle"].name
"olle"

I think there are thousand different ways you could solve it.

-- 
mvh Björn