On Tue, 24 Dec 2019 12:08:33 +0900 "Stephen J. Turnbull" <turnbull.stephen...@u.tsukuba.ac.jp> wrote: > David Mertz writes: > > > Even though I was the first person in this thread to suggest > > collections.OrderedSet, I'm "meh" about it now. As I read more and played > > with the sortedcollections package, it seemed to me that while I might want > > a set that iterated in a determinate and meaningful order moderately often, > > insertion order would make up a small share of those use cases. > > On the other hand, insertion order is one of the most prominent of the > determinate meaningful orders where you would have to do ugly things > to use "sorted" to get that order. Any application where you have an > unreliable message bus feeding a queue (so that you might get > duplicate objects but it's bad to process the same object twice) would > be a potential application of insertion-ordered sets.
In that case you probably want a separate persistent "seen" set. Because your queue can have been drained by the time a duplicate object arrives. (which means you probably want something more efficient, such as a sequence number) Regards Antoine. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/QANSVP7LU4OVMGKIGM25CJ4W24YYYVBD/ Code of Conduct: http://python.org/psf/codeofconduct/
