Message211792
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 as it supports all the protocol levels, and is always used [1]. 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. |
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Date |
User |
Action |
Args |
2014-02-21 02:34:52 | ethan.furman | set | recipients:
+ ethan.furman, barry, larry, eli.bendersky, serhiy.storchaka |
2014-02-21 02:34:52 | ethan.furman | set | messageid: <1392950092.38.0.675720437211.issue20679@psf.upfronthosting.co.za> |
2014-02-21 02:34:52 | ethan.furman | link | issue20679 messages |
2014-02-21 02:34:51 | ethan.furman | create | |
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