Re: [Python-ideas] Add sorted (ordered) containers

[Mahmoud Hashemi]

 I'm all for adding more featureful data structures. At the risk of
confusing Nick's folks, I think it's possible to do even better than
Sorted/Ordered for many collections. In my experience, the simple Ordered
trait alone was not enough of a feature improvement over the simpler
builtin, leading me to implement an OrderedMultiDict, for instance.
Another, more cogent example would be Boltons' IndexedSet:
http://boltons.readthedocs.io/en/latest/setutils.html

It's a normal MutableSet, with almost all the same time complexities,
except that you can do indexed_set[0] to get the first-added item, etc.
Sometimes it helps to think of it as a kind of UniqueList. If we're going
for more featureful containers, I say go all-in!

Mahmoud

On Fri, Oct 14, 2016 at 8:23 AM, Nick Coghlan  wrote:

> On 14 October 2016 at 06:48, Neil Girdhar  wrote:
> > Related:
> >
> > Nick posted an excellent answer to this question here:
> > http://stackoverflow.com/questions/5953205/why-are-
> there-no-sorted-containers-in-pythons-standard-libraries
>
> Ah, so this thread is why I've been getting SO notifications for that
> answer :)
>
> While I think that was a decent answer for its time (as standardising
> things too early can inhibit community experimentation - there was
> almost 12 years between Twisted's first release in 2002 and asyncio's
> provisional inclusion in the standard library in Python 3.4), I also
> think the broader context has changed enough that the question may be
> worth revisiting for Python 3.7 (in particular, the prospect that it
> may be possible to provide this efficiently without having to add a
> large new chunk of C code to maintain).
>
> However, given that Grant has already been discussing the possibility
> directly with Raymond as the collections module maintainer though,
> there's probably not a lot we can add to that discussion here, since
> the key trade-off is between:
>
> - helping folks that actually need a sorted container implementation
> find one that works well with typical memory architectures in modern
> CPUs
> - avoiding confusing folks that *don't* need a sorted container with
> yet another group of possible data structures to consider in the
> standard library
>
> *That* part of my original SO answer hasn't changed, it's just not as
> clearcut a decision from a maintainability perspective when we're
> talking about efficient and relatively easy to explain pure Python
> implementations.
>
> Cheers,
> Nick.
>
> --
> Nick Coghlan   |   ncogh...@gmail.com   |   Brisbane, Australia
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Re: [Python-ideas] Add sorted (ordered) containers

[Serhiy Storchaka]

On 13.10.16 23:36, Марк Коренберг wrote:

I think it should be one standardized implementation of such containers
in CPython.

For example, C++ has both ordered_map and unorderd_map.

Instead of trees, implementation may use SkipList structure, but this is
just implementation details.

Such structres imply fast insertion and deletion, ability to iterate,
and also memory efficiency.


I recommend to read thorough review articles written by Andrew Barnert:

http://stupidpythonideas.blogspot.com/2013/07/sorted-collections-in-stdlib.html

http://stupidpythonideas.blogspot.com/2014/04/sortedcontainers.html


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