[Python-Dev] Proposal: dict.with_values(iterable)

Inada Naoki songofacandy at gmail.com
Mon Apr 22 19:03:05 EDT 2019

On Tue, Apr 23, 2019 at 2:18 AM Chris Barker via Python-Dev
<python-dev at python.org> wrote:
> On Fri, Apr 12, 2019 at 10:20 AM Brett Cannon <brett at python.org> wrote:
>> This doesn't strike me as needing an optimization through a dedicated method.
> maybe a new dict mapping type -- "shared_dict" -- it would be used in places like the csv reader where it makes sense, but wouldn't impact the regular dict at all.
> you could get really clever an have it auto-convert to a regular dict when any changes were made that are incompatible with the shared keys...

My current idea is adding builder in somewhere in stdlib (maybe collections?):

  builder = DictBuilder(keys_tuple)
  value = builder(values)  # repeatedly called.

I don't want to add new mapping type because we already have shared key dict,
and changing mapping type may cause backward compatibility problem.

Inada Naoki  <songofacandy at gmail.com>

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