Adam Atlas 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.)
As others have mentioned, in general the answer is no. However, class
statements do have access to the name they're assigned, so you could
abuse a class statement like this::
>>> # your class whose instances need a name property
>>> class C(object):
... def __init__(self, name):
... self.name = name
... @classmethod
... def from_class_block(cls, name, bases, blockdict):
... return cls(name)
...
>>> # instances of your class with the appropriate names
>>> class instance:
... __metaclass__ = C.from_class_block
...
>>> instance.name
'instance'
Though it doesn't rely on private functions like sys._getframe, it's
still sure to confuse the hell out of your users. ;-)
STeVe
--
http://mail.python.org/mailman/listinfo/python-list
