Subclassing datetime.date

[John Bokma]

Sir Wilhelm the Sturdy <wgaggioli at gmail.com> writes:

F> Hi all,
>
> I recently attempted to subclass the datetime.date object resulting in
> horror and confusion, before submitting to a has-a relationship.
> That's all fine and dandy, but out of curiosity I'd like to know what
> I'm missing.
>
> I was attempting to allow more flexible instancing of an object, like
> so:
>
> import datetime
>
> class MyDate(datetime.date):
>
>     def __init__(self,*args,**kw):
>
>         if len(kw) + len(args) > 1:
>             self.construct(*args,**kw)
>
>     def construct(self,d,m=None,y=None,**kw):
>
>         today = datetime.date.today()
>         if m is None:
>             m = today.month
>         if y is None:
>             y = today.year
>
>         datetime.date.__init__(self,y,m,d,**kw)
>
>
> However, it wasn't having the desired effect. Indeed, I could still
> only instance it with 3 variables lest I get errors, and when I did
> call it with 3 variables it didn't reflect the order change I had
> implemented. Indeed, the properties were already set before it even
> got to the construct method.

__init__ is *not* the construction method, __new__ is (at least with new
style classes)

> Is there some kind of built in I'm missing here?

I guess __new__ but I am quite the newbie.

-- 
John Bokma                                                               j3b

Hacking & Hiking in Mexico -  http://johnbokma.com/
http://castleamber.com/ - Perl & Python Development