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

[Inada Naoki]

On Tue, Apr 23, 2019 at 11:30 AM Steve Dower <steve.dower at python.org> wrote:
>
> Or possibly just "dict(existing_dict).update(new_items)".
>

Do you mean .update accepts values tuple?
I can't think it's

> My primary concern is still to avoid making CPython performance
> characteristics part of the Python language definition. That only makes
> it harder for alternate implementations.

Note that this proposal is not only for key sharing dict:

* We can avoid rebuilding hash table again and again.
* We can avoid checking duplicated keys again and again.

These characteristics are not only for Python, but for all mapping
implementations using hash table.

-- 
Inada Naoki  <songofacandy at gmail.com>