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Thu May 2 17:15:02 CEST 2013 · https://mail.python.org/pipermail/python-dev/2013-May/125870.html

On 05/02/2013 07:57 AM, Barry Warsaw wrote:
> On May 01, 2013, at 11:54 AM, Larry Hastings wrote:
>
>> On 04/30/2013 11:29 PM, Ethan Furman wrote:
>>> On 04/30/2013 11:18 PM, Barry Warsaw wrote:
>>>> On Apr 28, 2013, at 11:50 PM, Ethan Furman wrote:
>>>>
>>>>> But as soon as:
>>>>>
>>>>>     type(Color.red) is Color          # True
>>>>>     type(MoreColor.red) is MoreColor  # True
>>>>>
>>>>> then:
>>>>>
>>>>>      Color.red is MoreColor.red  # must be False, no?
>>>>>
>>>>>
>>>>> If that last statement can still be True, I'd love it if someone >>> showed me
>>>>> how.
>>>>
>>>> class Foo:
>>>>       a = object()
>>>>       b = object()
>>>>
>>>> class Bar(Foo):
>>>>       c = object()
>>>>
>>>>>>> Foo.a is Bar.a
>>>> True
>>>
>>> Wow.  I think I'm blushing from embarrassment.
>>>
>>> Thank you for answering my question, Barry.
>>
>> Wait, what?  I don't see how Barry's code answers your question.  In his
>> example, type(a) == type(b) == type(c) == object.  You were asking "how can
>> Color.red and MoreColor.red be the same object if they are of different
>> types?"
>>
>> p.s. They can't.
>
> Sure, why not?  In "normal" Python, Bar inherits a from Foo, it doesn't define
> it so it's exactly the same object.  Thus if you access that object through
> the superclass, you get the same object as when you access it through the
> subclass.
>
> So Foo.a plays the role of Color.red and Bar.a plays the role of
> MoreColor.red.  Same object, thus `Foo.a is Bar.a` is equivalent to `Color.red
> is MoreColor.red`.

Same object, true, but my question was if `type(Bar.a) is Bar`, and in your reply `type(Bar.a) is object`.

--
~Ethan~

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[Python-Dev] enum discussion: can someone please summarize open issues?