[Python-Dev] Guarantee ordered dict literals in v3.7?

[Peter Ludemann]

Isn't ordered dict also useful for **kwargs?

If it turns out that there's a dict implementation that's faster by not
preserving order, collections.UnorderedDict could be added.
There could also be specialized implementations that pre-size the dict (cf:
C++ unordered_map::reserve), etc., etc.
But these are all future things, which might not be necessary.

On 5 November 2017 at 12:44, Sven R. Kunze <srkunze at mail.de> wrote:

> +1 from me too.
>
> On 04.11.2017 21:55, Jim Baker wrote:
>
> +1, as Guido correctly recalls, this language guarantee will work well
> with Jython when we get to the point of implementing 3.7+.
>
> On Sat, Nov 4, 2017 at 12:35 PM, Guido van Rossum <guido at python.org>
> wrote:
>
>> This sounds reasonable -- I think when we introduced this in 3.6 we were
>> worried that other implementations (e.g. Jython) would have a problem with
>> this, but AFAIK they've reported back that they can do this just fine. So
>> let's just document this as a language guarantee.
>>
>> On Sat, Nov 4, 2017 at 10:30 AM, Stefan Krah <stefan at bytereef.org> wrote:
>>
>>>
>>> Hello,
>>>
>>> would it be possible to guarantee that dict literals are ordered in v3.7?
>>>
>>>
>>> The issue is well-known and the workarounds are tedious, example:
>>>
>>>    https://mail.python.org/pipermail/python-ideas/2015-Decembe
>>> r/037423.html
>>>
>>>
>>> If the feature is guaranteed now, people can rely on it around v3.9.
>>>
>>>
>>>
>>> Stefan Krah
>>>
>>>
>>>
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>>
>>
>>
>> --
>> --Guido van Rossum (python.org/~guido <http://python.org/%7Eguido>)
>>
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>
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