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

Yury Selivanov yselivanov.ml at gmail.com
Thu Apr 14 20:06:25 EDT 2016

On 2016-04-14 4:42 PM, Armin Rigo wrote:
> 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".


{}.version_tag == {}.version_tag == 0
{'a':1}.version_tag != {'a':1}.version_tag


For my patches I need globally unique version tags
(making an exception for empty dicts is OK).


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