Alex Martelli wrote:
> Pierre Rouleau <[EMAIL PROTECTED]> wrote:
>
>
>>Hi all,
>>
>>Is there any reason that under Python you cannot instantiate the object
>>class and create any attributes like you would be able for a normal class?
>
>
> Yep: instances of type object do not have a __dict__ and therefore there
> is no place to put any attributes. This is necessary to allow ANY
> subclass of object, and thus any type whatsoever, to lack a per-instance
> __dict__ (and thus to save its per-instance memory costs),
Makes sense. I was under the impresssion that instances of type object
did have a __dict__ but was hidden for some reason. I should have known
... explicit is better than implicit...
>
>
>>Being able to do it would seem a natural way of declaring namespaces.
>
>
> I find that ns = type('somename', (), dict(anattribute=23)) isn't too
> bad to make a namespace ns, though it has some undesirable issues (e.g.,
> ns is implicitly callable, which may make little sense for a namespace).
>
> At any rate, any natural way of declaring a namespace SHOULD allow
> arbitrary named arguments in the instantiation call -- bending
> principles to give each instance of object a __dict__ would still not
> fix that, so that wouldn't do much. I think it's worth the minor bother
> to write out something like
>
> class Namespace(object):
> def __init__(self, **kwds): self.__dict__ = kwds
>
> and I generally go further anyway, by defining at least a repr that
> shows the attributes' names and values (very useful for debugging...).
>
>
That's what I do too, but sometimes i just want to have a quick holder
attribute in a class and am lazy to do it. I could declare one such
class inside a module and import it but again, that means importing,
name space of the module, etc...
I can understand the design decision not to give object a __dict__, but
I wonder if i'd be a good idea to have a class that derives from object
and has a __dict__ to be in the standard library. I posted the original
question because I run into this quite often and I just saw a post a
little before mine ("self modifying code") where the idiom was used.
--
Pierre Rouleau
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