[issue26013] Pickle protocol 2.0 not loading in python 3.5
New submission from Anil Kulkarni: Pickles created with python 3.4.X will not load with python 3.5.X if they include a collections.OrderedDict To reproduce this issue, simply create a pickle of an OrderedDict on python 3.4.3 with protocol=2 and try to open it on 3.5. I have included a simple script to demonstrate this issue. I believe this is related to this bug: https://bugs.python.org/issue18473 As to the real-world implications: The python package Celery uses protocol=2 by default when serializing with pickle, and thus a celery web running 3.5 cannot receive the results of a worker running 3.4 For celery specifically, there is a workaround by setting the PICKLE_PROTOCOL environment variable, but this is a core python issue. P.S. This is the first bug I've filed with python so please let me know if there's something else I should be including. Thanks! -- files: b.py messages: 257524 nosy: anilredshift priority: normal severity: normal status: open title: Pickle protocol 2.0 not loading in python 3.5 type: behavior versions: Python 3.5 Added file: http://bugs.python.org/file41503/b.py ___ Python tracker <http://bugs.python.org/issue26013> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26013] Pickle protocol 2.0 not loading in python 3.5
Anil Kulkarni added the comment: Hi Serhiy, I have done some more investigation this morning and I have come across two distinct issues. The first is that pickles (specifically the pickle in my earlier message) created in python 3.0->3.4.3 do not load on python 2.7.10. The exception is 3.5.1, which produces a pickle that DOES load on 2.7.10 This is unfortunate but not a regression The second issue is that pickles created by python 3.0->3.4.3 do NOT load in python 3.5 This is a regression, in the sense that the pickle created by 3.0->3.4.3 is compatible with every other version of python (I haven't tested every single combination here, but several) >From the language perspective, it may be that 3.4.X has incorrect code, but >from a compatibility perspective, 3.5 is breaking the promise that pickles are >compatible across versions of python. I write this as justification that python 3.5 should fix this regression in compatibility with 3.0 -> 3.4.3. At the very least 3.5 should have a shim behavior to fallback and allow it to import these pickles correctly. Thanks, Anil -- ___ Python tracker <http://bugs.python.org/issue26013> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue26013] Pickle protocol 2.0 not loading in python 3.5
Anil Kulkarni added the comment: Ah, sorry I misunderstood. Thanks for the quick turnaround! -- ___ Python tracker <http://bugs.python.org/issue26013> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
