How object's setattr differs from inherited?

[Andrew Berg]

On 2011.07.29 10:12 AM, Ciantic wrote:
>>>> class MyObject(object):
> ...     pass
> ...
>>>> my = MyObject()
>>>> my.myvar = 'value' # No error!
>>>>
>>>> obj = object()
>>>> obj.myvar = 'value'  # Causes error!
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> AttributeError: 'object' object has no attribute 'myvar'
> 
> Why simple inheritance from object does not cause errors at setattr,
> yet direct init of object() does?
object objects have no __dict__. User-defined objects typically do. Each
child of MyObject would likely have __dict__ as well.

> I was trying to "decor" objects, lists etc with own attributes that
> could be used in templates and was sadly not permitted to do so:
> 
>>>> something = [1,2]
>>>> something.myvar = 'value'
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> AttributeError: 'list' object has no attribute 'myvar'
Lists have no __dict__, and AFAIK, there's no reason they should.

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