Is there any reason that these features couldn't be added to OrderedDict (which is a linked list)? https://github.com/python/cpython/blob/master/Objects/odictobject.c
On Sat, Aug 1, 2020, 9:13 PM Inada Naoki firstname.lastname@example.org wrote:
On Sun, Aug 2, 2020 at 2:34 AM Christopher Barker email@example.com wrote:
On Sat, Aug 1, 2020 at 2:28 AM Marco Sulla Marco.Sulla.Python@gmail.com
On Sat, 1 Aug 2020 at 03:00, Inada Naoki firstname.lastname@example.org
Please teach me if you know any algorithm which has no hole, O(1) deletion, preserving insertion order, and efficient and fast as array.
I would think the goal here would be to re-order once in a while to
remove the holes. But that would take time, of course, so you wouldn't want to do it on every deletion. But when?
One option: maybe too specialized, but it could re-pack the array when
an indexing operation is made -- since that operation is O(N) anyway. And that would then address the issue of performance for multiple indexing operations -- if you made a bunch of indexing operation in a row without deleting (which would be the case, if this is an alternative to making a copy in a Sequence first), then the first one would repack the internal array (presumably faster than making a copy) and the rest would have O(1) access.
Repacking is mutation, and mutating dict while iterating it breaks the iterator. But `d.items()` don't looks like mutation.
Given that this use case doesn't appear to be very important, I doubt
it's worth it, but it seems it would be possible.
Another thought -- could the re-packing happen whenever the entire dict
is iterated through? Though maybe there's no way to know when that's going to happen -- all you get are the individual calls for the next one, yes?
You are right. it couldn't.
-- Inada Naoki email@example.com _______________________________________________ Python-ideas mailing list -- firstname.lastname@example.org To unsubscribe send an email to email@example.com https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://firstname.lastname@example.org/message/ED2GRW... Code of Conduct: http://python.org/psf/codeofconduct/