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Title: Pickle nested names with protocols < 4
Type: enhancement Stage: resolved
Components: Library (Lib) Versions: Python 3.5
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: serhiy.storchaka Nosy List: alexandre.vassalotti, pitrou, python-dev, serhiy.storchaka, vstinner
Priority: normal Keywords: patch

Created on 2015-03-08 17:50 by serhiy.storchaka, last changed 2022-04-11 14:58 by admin. This issue is now closed.

File name Uploaded Description Edit
pickle_nested_names_2.patch serhiy.storchaka, 2015-03-08 20:45 review
Messages (9)
msg237548 - (view) Author: Serhiy Storchaka (serhiy.storchaka) * (Python committer) Date: 2015-03-08 17:50
Proposed patch allows Python implementation of the pickle module to pickle nested names (e.g. methods) with protocols < 4. Pickled data is compatible with old releases.

If this is good I'll write C implementation.
msg237567 - (view) Author: Serhiy Storchaka (serhiy.storchaka) * (Python committer) Date: 2015-03-08 20:45
Fixed few bugs and added C implementation.
msg237568 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2015-03-08 20:50
Interesting. I have only skimmed through the patch, but +1 on the principle.
msg239362 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2015-03-26 23:08
Hum, I don't know well the pickle module. Is it backward compatible? Should Python 2 be able to unserialize data serialized by Python 3? If yes, can you patch break this compatibility?

It is unclear to me if it makes sense to even modify protocols different than the latest version.
msg239364 - (view) Author: Serhiy Storchaka (serhiy.storchaka) * (Python committer) Date: 2015-03-26 23:17
Pickle is backward compatible and Python 2 usually is able to unpickle data pickled by Python 3 with protocol < 3. The patch doesn't break compatibility. Current default protocol is 3 for compatibility with older Python 3 versions. It is used in multiprocessing and this is not configurable.
msg239368 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2015-03-27 00:25
> It is used in multiprocessing and this is not configurable.

Oh, it would be nice to switch to version 4 by default, or make it
configurable. I read that the version 4 is faster.
msg239389 - (view) Author: Serhiy Storchaka (serhiy.storchaka) * (Python committer) Date: 2015-03-27 12:13
Issue23403. But looks it is early yet for this.

Note that this patch doesn't modify protocols. It just makes the pickler more smart and able to serialize more objects with existing protocols. It is the same as add pickle support for some type that didn't support the pickling before.
msg239683 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-03-31 11:09
New changeset ca12465418bd by Serhiy Storchaka in branch 'default':
Issue #23611: Serializing more "lookupable" objects (such as unbound methods
msg239711 - (view) Author: Roundup Robot (python-dev) (Python triager) Date: 2015-03-31 13:58
New changeset f78b9f700d45 by Serhiy Storchaka in branch 'default':
Issue #23611: Fixed enums pickling tests.  Now all picklings work with all
Date User Action Args
2022-04-11 14:58:13adminsetgithub: 67799
2015-03-31 16:49:01serhiy.storchakasetstatus: open -> closed
resolution: fixed
stage: patch review -> resolved
2015-03-31 13:58:40python-devsetmessages: + msg239711
2015-03-31 11:09:45python-devsetnosy: + python-dev
messages: + msg239683
2015-03-27 12:13:23serhiy.storchakasetmessages: + msg239389
2015-03-27 00:25:31vstinnersetmessages: + msg239368
2015-03-26 23:17:34serhiy.storchakasetmessages: + msg239364
2015-03-26 23:08:57vstinnersetnosy: + vstinner
messages: + msg239362
2015-03-24 20:07:15serhiy.storchakasetassignee: serhiy.storchaka
2015-03-08 21:15:01serhiy.storchakasetfiles: - pickle_nested_names.patch
2015-03-08 20:50:21pitrousetmessages: + msg237568
2015-03-08 20:45:17serhiy.storchakasetfiles: + pickle_nested_names_2.patch

messages: + msg237567
2015-03-08 17:50:40serhiy.storchakacreate