Ethan Furman added the comment: When I implemented pickle support I did not have a complete understanding of the pickle protocols nor how to best use them. As a result, I picked __getnewargs__ and only supported protocols 2 and 3 (4 didn't exist yet).
Serhiy came along and explained a bunch of it to me, so now I know that __reduce_ex__ is the best choice [1] as it supports all the protocol levels, and is always used. The patch removes __getnewargs__ and makes __reduce_ex__ The One Obvious Way, but if it does not go in to 3.4.0 then I won't be able to remove __getnewargs__ because of backwards compatibility. All the tests still pass, and the new test for subclassing to pickle by name passes. [1] pickle supports two low-level methods: __reduce__ and __reduce_ex__; __reduce_ex__ is more powerful and is the preferred method. If a mix-in class to Enum defines __reduce_ex__ and Enum only defines __reduce__, Enum's __reduce__ will not be called. ---------- priority: normal -> high resolution: fixed -> stage: committed/rejected -> commit review status: closed -> open versions: +Python 3.4 -Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20653> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
