Re: [matplotlib-devel] Patch rough-draft

[John H. <jdh...@ac...>]

>>>>> "Fernando" == Fernando Perez <Fer...@co...> writes:

    Fernando> Just a minor comment: insert(0) is an expensive (O(N))
    Fernando> operation on lists. This kind of problem might be better
    Fernando> addressed with a deque
    Fernando> (http://www.python.org/dev/doc/devel/lib/module-collections.html,
    Fernando> could be backported to py2.3).

If I read the patch correctly, usage_stack is being used as a simple
counter.  

I think the data structure we want is a class derived from dict that
pops elements off (preferably intelligently, ie pops the ones which
haven't been accessed in a while) when the dict length gets too long. 
In other words, we don't need to structures (cached and usage_stack)
to do the work of one

There must be such a beast in the cookbook or elsewhere, a cache
object which works like a dict but has a max size...

JDH