[Python-Dev] subclassing builtin data structures

[Guido van Rossum]

Are you willing to wait 10 days for an answer? I'm out of round tuits for a
while.

On Fri, Feb 13, 2015 at 10:22 AM, Alexander Belopolsky <
alexander.belopolsky at gmail.com> wrote:

>
> On Fri, Feb 13, 2015 at 1:19 PM, Alexander Belopolsky <
> alexander.belopolsky at gmail.com> wrote:
> >>
> >> FWIW you're wrong when you claim that "a constructor is no different
> from any other method". Someone else should probably explain this (it's an
> old argument that's been thoroughly settled).
> >
> >
> > Well, the best answer I've got in the past [1] was "ask on python-dev
> since Guido called the operator overriding expectation." :-)
>
>
> And let me repost this bit of history [1]:
>
> Here is the annotated pre-r82065 code:
>
>  39876 gvanrossum     def __add__(self, other):
>  39876 gvanrossum         if isinstance(other, timedelta):
>  39928 gvanrossum             return self.__class__(self.__days +
> other.__days,
>  39876 gvanrossum                                   self.__seconds +
> other.__seconds,
>  39876 gvanrossum                                   self.__microseconds +
> other.__microseconds)
>  40207    tim_one         return NotImplemented
>  39876 gvanrossum
>
>
> [1] http://bugs.python.org/issue2267#msg125979
>



-- 
--Guido van Rossum (python.org/~guido)
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