[Python-ideas] namedtuple literals [Was: RE a new namedtuple]

[Michel Desmoulin]

Le 29/07/2017 à 18:14, Alex Walters a écrit :
> My $0.02 on the entire series of nametuple threads is… there **might**
> be value in an immutable namespace type, and a mutable namespace type,
> but namedtuple’s promise is that they can be used anywhere a tuple can
> be used.  If passing in kwargs to create the potential replacement to
> namedtuple is sensitive to dict iteration order, it really isn’t a
> viable replacement for namedtuple.

In Python 3.6, kwargs order is preserved and guaranteed. It's currently
implemented by relying on the non guaranteed dict order. But the 2 are
not linked. The spec does guaranty that for now on, kwargs order is
always preserved whether the dict order is or not.

> 
>  
> 
> I do feel like there isn’t that big of a usecase for an immutable
> namespace type as there is for a namedtuple.  I would rather namedtuple
> class creation be quicker.
> 
>  
> 
>  
> 
> *From:* Python-ideas
> [mailto:python-ideas-bounces+tritium-list=sdamon.com at python.org] *On
> Behalf Of *Chris Barker
> *Sent:* Friday, July 28, 2017 8:27 PM
> *To:* Ethan Furman <ethan at stoneleaf.us>
> *Cc:* Python-Ideas <python-ideas at python.org>
> *Subject:* Re: [Python-ideas] namedtuple literals [Was: RE a new namedtuple]
> 
>  
> 
> On Thu, Jul 27, 2017 at 7:42 PM, Ethan Furman <ethan at stoneleaf.us
> <mailto:ethan at stoneleaf.us>> wrote:
> 
>     How I get the point[0] == 3?  The first definition of an ntuple had
>     the order as x, y, and since the proposal is only comparing field
>     names (not order), this (y, x) ntuple ends up being reversed to how
>     it was specified.
> 
>  
> 
> I'm not sure there ever was a "proposal" per se, but:
> 
> ntuple(x=a, y=b)
> 
>  
> 
> had better be a different type than:
> 
> ntuple(y=b, x=a)
> 
> but first we need to decide if we want an easy way to make an
> namedtuple-like object or a SimpleNemaspace-like object....
> 
>  
> 
> but if you are going to allow indexing by integer, then order needs to
> be part of the definition.
> 
>  
> 
> -CHB
> 
> 
> -- 
> 
> 
> Christopher Barker, Ph.D.
> Oceanographer
> 
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> 
> 
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