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Re: duck typing assert

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On Sat, Nov 10, 2012 at 1:01 AM, Andriy Kornatskyy
<andriy.kornatskyy@live.com> wrote:
>
> 1. In looks-like we check features of Foo (that may be superset) of what IFoo offers.
>
> assert looks(Foo).like(IFoo)
>
> 2. We can check if Foo is limited to IFoo only:
>
> assert looks(IFoo).like(Foo)
>
> So it valid to have both asserts.

You'll almost never need #2, but since there's no difference between a
"class" and an "interface", it's perfectly legal to switch them
around.

But I would generally expect that unrecognized methods are never a
problem (assuming they don't collide with anything) - that, as in
Steven's example, it's fine to have an actor who can sing when you
don't need her to. When you post job openings, you don't normally ask
for someone with "5+ years Python experience and unable to program in
REXX" [1]. You're checking for a minimum set of requirements.

[1] Though I suppose you might ask for someone who's unable to program
in Pascal. Might save you some hassle.

ChrisA

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duck typing assert‏ Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2012-11-08 20:34 +0300
  Re: duck typing assert‏ Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-11-08 23:33 +0000
    Re: duck typing assert Ian Kelly <ian.g.kelly@gmail.com> - 2012-11-08 18:00 -0700
      Re: duck typing assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-11-09 13:36 +0000
        RE: duck typing assert Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2012-11-09 17:01 +0300
        Re: duck typing assert Chris Angelico <rosuav@gmail.com> - 2012-11-10 01:15 +1100
        RE: duck typing assert Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2012-11-09 17:37 +0300
    Re: duck typing assert Chris Angelico <rosuav@gmail.com> - 2012-11-09 17:14 +1100
    RE: duck typing assert Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2012-11-09 13:26 +0300
    RE: duck typing assert "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-11-09 17:37 +0000
    RE: duck typing assert Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2012-11-09 20:55 +0300

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