On Thu, Dec 19, 2019 at 5:39 PM Nick Coghlan <ncogh...@gmail.com> wrote:
> I took Larry's request a slightly different way: he has a use case where > he wants order preservation (so built in sets aren't good), but combined > with low cost duplicate identification and elimination and removal of > arbitrary elements (so lists and collections.deque aren't good). Organising > a work queue that way seems common enough to me to be worthy of a stdlib > solution that doesn't force you to either separate a "job id" from the > "job" object in an ordered dict, or else use an ordered dict with "None" > values. > It's not obvious to me that insertion order is even the most obvious or most commonly relevant sort order. I'm sure it is for Larry's program, but often a work queue might want some other order. Very often queues might instead, for example, have a priority number assigned to them. The widely used third-party `sortedcollections` module maintains either "natural" order or some key order. That could be engineered to be insertion order fairly easily. Admittedly, 'OrderedSet' sounds a bit different from 'SortedSet'. In [8]: sortedcontainers.SortedSet(['Wake Up', 'Drink Coffee', 'Make Breakfast']) Out[8]: SortedSet(['Drink Coffee', 'Make Breakfast', 'Wake Up']) In [9]: sortedcontainers.SortedSet(['Wake Up', 'Drink Coffee', 'Make Breakfast'], key=lambda s: s[-1]) Out[9]: SortedSet(['Drink Coffee', 'Wake Up', 'Make Breakfast'], key=<function <lambda> at 0x7f68f5985400>) In [10]: 'Make Breakfast' in tasks Out[10]: True -- Keeping medicines from the bloodstreams of the sick; food from the bellies of the hungry; books from the hands of the uneducated; technology from the underdeveloped; and putting advocates of freedom in prisons. Intellectual property is to the 21st century what the slave trade was to the 16th.
_______________________________________________ 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/KKYFUXUHYIQB5Q532FV4YXDLKMRX55XY/ Code of Conduct: http://python.org/psf/codeofconduct/
