[issue4712] Document pickle behavior for subclasses of dicts/lists

Changes by Serhiy Storchaka : -- nosy: +alexandre.vassalotti, pitrou ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscri

[issue4712] Document pickle behavior for subclasses of dicts/lists

Serhiy Storchaka added the comment: The order in copy was changed by issue1100562. -- ___ Python tracker ___ ___ Python-bugs-list maili

[issue4712] Document pickle behavior for subclasses of dicts/lists

Serhiy Storchaka added the comment: The copy module uses the same __reduce__ protocol, but reconstruct the object in different order, first set state, then add items. This discrepancy causes a difference between results of pickle/unpickle and copy operations. Example: >>> class L(list): ...

[issue4712] Document pickle behavior for subclasses of dicts/lists

Changes by Eric Snow : -- nosy: +eric.snow versions: +Python 3.5 -Python 3.2, Python 3.3 ___ Python tracker ___ ___ Python-bugs-list ma

[issue4712] Document pickle behavior for subclasses of dicts/lists

Changes by Ezio Melotti : -- versions: +Python 3.2, Python 3.3, Python 3.4 -Python 2.6, Python 3.0, Python 3.1 ___ Python tracker ___

[issue4712] Document pickle behavior for subclasses of dicts/lists

Changes by Daniel Diniz : -- dependencies: +pickle.dumps cannot save instance of dict-derived class that overrides __getattribute__ ___ Python tracker ___ ___

[issue4712] Document pickle behavior for subclasses of dicts/lists

Changes by Daniel Diniz : -- keywords: +easy ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.

[issue4712] Document pickle behavior for subclasses of dicts/lists

Raymond Hettinger added the comment: The behavior is a PITA. It means that dict subclasses the redefine __setitem__ have unpleasant pickling challenges. The __setitem__ insertions are called before the subclass can initialize. The workaround involves a funky dance using __reduce__. See colle

[issue4712] Document pickle behavior for subclasses of dicts/lists

New submission from Georg Brandl : When unpickling dict subclasses, the dict is filled via setitem before __setstate__ is called. This, and other behavior around subclasses of classes that have special pickle behavior should be documented. -- assignee: georg.brandl components: Documenta