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| Date | Mon, 19 Jan 2015 18:00:51 -0600 |
| From | Tim Chase <python.list@tim.thechases.com> |
| To | Michael Torrie <torriem@gmail.com> |
| Subject | Re: Trees |
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On 2015-01-19 16:19, Michael Torrie wrote: > On 01/19/2015 04:08 PM, Steven D'Aprano wrote: > > Zachary Gilmartin wrote: > >> Why aren't there trees in the python standard library? > > > > Possibly because they aren't needed? Under what circumstances > > would you use a tree instead of a list or a dict or combination > > of both? While not an abundance of times, I've had a plurality of occasions when I've wanted characteristics of a red/black tree where I wanted O(log n) insertion/deletion/initial-access and O(1) access to neighbors. > > Also, what sort of tree? Binary tree? Binary search tree? > > Red/black tree? AVL tree? Splay tree? B-tree? T-tree? Scapegoat > > tree? General n-ary tree? Every possible type of tree yet > > invented? > > Don't forget left-child,right-sibling trees. > > As I go through your list of trees, I can't find any tree type that > cannot be easily and efficiently constructed with lists, possibly > with dicts. While the data-structures can easily be composed out of lists/dicts, the algorithms that go along with them (such as red/black trees with their insertion/deletion gymnastics) would be nice to have in the stdlib so they wouldn't have to be reimplemented (or sought out and downloaded, and added to the configuration/distribution) every time someone wanted that particular tree's characteristics. Much of that could be addressed with a library of algorithms much like heapq operates on a list. -tkc
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Trees Zachary Gilmartin <zacharygilmartin@gmail.com> - 2015-01-19 17:06 -0500
Re: Trees Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-20 10:08 +1100
Re: Trees Michael Torrie <torriem@gmail.com> - 2015-01-19 16:19 -0700
Re: Trees Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-01-19 15:52 -0800
Re: Trees Tim Chase <python.list@tim.thechases.com> - 2015-01-19 18:00 -0600
Re: Trees Nicholas Cole <nicholas.cole@gmail.com> - 2015-01-20 09:23 +0000
Re: Trees Paul Rubin <no.email@nospam.invalid> - 2015-01-20 10:02 -0800
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