[Python-Dev] LinkedHashSet/LinkedHashMap equivalents

Eli Stevens (WG.c) listsub at wickedgrey.com
Thu Mar 10 01:17:49 CET 2005

Steven Bethard wrote:
> Thomas Heller <theller at python.net> wrote:
>>[About an ordered dictionary]
> Well, that was basically the question I posed.  So far I've seen only
> one use for it, and that one is better served by adding a function to
> itertools.  What use do you have for it other than filtering
> duplicates from a list while retaining order?

The primary use case I have deals with DB result sets*.  The ordering of 
the rows returned from a query is important, so keeping the iteration 
order is nice.  Most of the tables I deal with have keys of some kind, 
and being able to pull out a result row by key is also nice.  Granted, I 
rarely use /both/ at the same time, but it is nice to not have to 
specify how the result set will be used when I retrieve it.

To me, this seems to be the same concept as the config file parsing 
previously mentioned.

I don't feel qualified to have an opinion** about inclusion in the 
stdlib, much less vote.

relurkin'ly yrs,

[*] - In my case, it's actually coded in Java, for work.  There might be 
a reason that this problem isn't language-generic, but the 1.5 minutes I 
spent thinking about it were not illuminating.

[**] - Yet I have one anyway.  This kind of datatype seems one of those 
easy-to-get-half-right things that could benefit from a solid 
implementation.  It also doesn't strike me as controversial in terms of 
API or internal structure.

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