LRU cache (and other things missing from the standard library ...)

[Gerhard Haering]

I recently implemented a LRU cache. And I wondered why such a useful class is
not already in the standard library. The only thing I found was a cookbook
entry but the comments said it was problematic.

Btw. my implementation is currently at
http://initd.org/svn/initd/pysqlite/trunk/misc/lru.py Does anybody see any
problems with this code?

I've already started translating it into C (*) , which speeds it up by between
factor 5 to 8. Maybe a candidate for the standard library once it's finished?

-- Gerhard

(*) http://initd.org/svn/initd/pysqlite/trunk/src/cache.c is the first iteration.
--
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

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[Paul Moore]

I recently implemented a LRU cache. And I wondered why such a useful class is
not already in the standard library. The only thing I found was a cookbook
entry but the comments said it was problematic.
[...]

I've already started translating it into C (*) , which speeds it up by between
factor 5 to 8. Maybe a candidate for the standard library once it's finished?

Would this be a suitable addition for the collections module (which
currently only has deque in it)?

I'm not sure if a LRU cache counts as a "collection" in that sense. I
looked at the code briefly, but don't really follow it yet...

Paul.