[Python-ideas] Add OrderedSet now that OrderedDict is in collections

[Mart Sõmermaa]

On Fri, May 8, 2009 at 9:12 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> What are the use cases?  An 'ordered set' is basically a list + set.

A list with no duplicate values (can be alternatively called unique
list) is a common problem judging on the following:

http://www.google.com/codesearch?q=lang%3Apython+list+unique
http://www.google.com/codesearch?q=lang%3Apython+list+duplicates
http://www.peterbe.com/plog/uniqifiers-benchmark/
http://code.activestate.com/recipes/52560/
http://www.google.ee/search?q=python+unique+list

My use case stems from http://bugs.python.org/issue5877 ,
see http://github.com/mrts/qparams/blob/bf1b29ad46f9d848d5609de6de0bfac1200da310/qparams.py#L365