[Python-Dev] RFC: PEP 509: Add a private version to dict

[Victor Stinner]

Hi,

2016-04-14 22:42 GMT+02:00 Armin Rigo <arigo at tunes.org>:
> Hi Victor,
>
> On 14 April 2016 at 17:19, Victor Stinner <victor.stinner at gmail.com> wrote:
>> Each time a dictionary is created, the global
>> version is incremented and the dictionary version is initialized to the
>> global version.
>
> A detail, but why not set the version tag of new empty dictionaries to
> zero, always?   Same after a clear().  This would satisfy the
> condition: equality of the version tag is supposed to mean "the
> dictionary content is precisely the same".

You're right that incrementing the global version is useless for these
specific cases, and using the version 0 should work. It only matters
that the version (version? version tag?) is different.

I will play with that. If I don't see any issue, I will update the PEP.

It's more an implementation detail, but it may help to mention it in the PEP.

Victor