On Mon, Aug 8, 2016 at 3:08 PM, אלעזר <elaz...@gmail.com> wrote:
> On Tue, Aug 9, 2016 at 12:29 AM Guido van Rossum <gu...@python.org> wrote:
>
>> On Mon, Aug 8, 2016 at 2:11 PM, אלעזר <elaz...@gmail.com> wrote:
>>
>>> Feels like named parameters are better off being an OrderedDict in the
>>> first place.
>>>
>>
>> PEP 468.
>>
>>
> Sorry, I should have read this PEP before.
>
No problem, it's fine to participate before reading *everything*!
> NamedTuple pushes OrderedDict to become kind of builtin.
>>>
>>
>> Why? Having both in the collections module is good enough.
>>
>
> What I meant in becoming builtin is not the accessibility of the name, but
> the parallel incremental support of namedtuple, OrderedDict and (as I find
> out) order of **kwargs.
>
Well, they're all already in the stdlib, although namedtuple is written in
Python, OrderedDict in C (recently), and **kwarg is ancient.
> In much the same way that class is made out of dict (and keeps one),
> namedtuple is an OrderedDict (and keeps one).
>
I'm not sure if you're talking about the class or the instances. A class
instance usually has a dict (unless if it has __slots__ and all its base
classes have __slots__). But a namedtuple instance does not have a dict or
OrderedDict -- it is a tuple at heart.
> Much like dict has a constructor `dict(a=1, b=2.0)` and a literal `{'a' :
> 1, 'b' : 2.0}`, OrderedDict has its OrderedDict(a=1, b=2.0) and should
> have the literal ('a': 1, 'b': 2.0).
>
That's debatable at least, and probably there are better solutions.
> Replace 1 and 2 with int and float and you get a very natural syntax for a
> NamedTuple that is the type of a matching OrderedDict.
> And in my mind, the requirement for type names matches nicely the
> enforcement of immutability.
>
> Continuing this thought, the annotations for the class is actually its
> structural type. It opens the door for future requests for adding e.g. an
> operator for structural equivalence.
>
> This is all very far from the current language, so it's only thoughts and
> not really ideas; probably does not belong here. Sorry about that.
>
> ~Elazar
>
--
--Guido van Rossum (python.org/~guido)
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