[Tutor] calling setters of superclasses

Alan Gauld alan.gauld at btinternet.com
Mon Dec 20 17:23:27 CET 2010

"Steven D'Aprano" <steve at pearwood.info> wrote

>> I don't use properties in Python very often (hardly ever in fact) 
>> and I've never used @setter so there may be naming requirements I'm 
>> not aware of. But in general I'd avoid having two methods with the 
>> same name.
> That's generally good advice, since one will over-write the other, 
> but in this specific case, the following is completely bad:

Yep, that's what I suspected might be the case.

> If you don't use the same name, chaos reigns:
> >>> class Broken(object):
> ...     def __init__(self):
> ...     @property
> ...     def x(self):
> ...     @x.setter
> ...     def set_x(self, value):
> ...
> >>> obj = Broken()
> >>> obj.x = 20
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> AttributeError: can't set attribute

All part of the reason I don't particularly like properties in Python.
It feels like it goes against the principle of explicit is better than
implicit... That and the fact that properties encourage a
data-centric view of objects.

Alan G.

More information about the Tutor mailing list