[Python-Dev] Analog of PEP 448 for dicts (unpacking in assignment with dict rhs)

Nick Coghlan ncoghlan at gmail.com
Sun Nov 12 05:06:06 EST 2017

On 11 November 2017 at 16:22, Jelle Zijlstra <jelle.zijlstra at gmail.com> wrote:
> 2017-11-10 19:53 GMT-08:00 Ben Usman <bigobangux at gmail.com>:
>> I was not able to find any PEPs that suggest this (search keywords:
>> "PEP 445 dicts", "dictionary unpacking assignment", checked PEP-0),
>> however, let me know if I am wrong.
> It was discussed at great length on Python-ideas about a year ago. There is
> a thread called "Unpacking a dict" from May 2016.

I tend to post this every time the topic comes up, but: it's highly
unlikely we'll get syntax for this when we don't even have a builtin
to extract multiple items from a mapping in a single operation.

So if folks would like dict unpacking syntax, then a suitable place to
start would be a proposal for a "getitems"  builtin that allowed
operations like:

    b, a  = getitems(d, ("b", "a"))

operator.itemgetter and operator.attrgetter may provide some
inspiration for possible proposals.


Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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