Noufal Ibrahim <nou...@nibrahim.net.in> writes: > Rahul R <rahul8...@gmail.com> writes: > >> I dont intent to pre optimize things , I am rather driven by curiosity on >> how one could do that. > > I'm with Anand on recommendations but like you, I'm curious as to > whether this is possible. Do you have some estimates of size for your > dictionary and the average size for the values? > > I'm trying some experiments.
My experiments were not particularly revealing. However, take a look at http://hg.python.org/cpython/file/3e02d70cd07b/Objects/dictnotes.txt There are *compile time* parameters that can be tweaked in the implementation which will affect behaviour. These things all affect performance in subtle ways and the values that they've chosen are probably based on varied data which best represent real life cases. Tweaking them will probably be a micro optimisation that you'll need only for specific cases. The ones I see are dictionary size, load, growth rate, sparseness and shrinkage rate. The last two are things you can tweak to get the behaviour you want. However, as it notes, shrinkage checks are never done when an item is removed. So, it looks as though you have to actually add an item after deleting everything else for the dictionary itself to shrink which is an interesting quirk. Another thing that occurs to me is that the "size" of the dictionary is probably dominated by the size of the keys and, perhaps more so, the values. Unless these are super small, I don't think the extra overhead of the dictionary itself will become a burden. In other words, the empty slots you're worried about shouldn't be a problem unless your actual data is so small that the free slots are the dominant data. [...] -- Cordially, Noufal http://nibrahim.net.in _______________________________________________ BangPypers mailing list BangPypers@python.org http://mail.python.org/mailman/listinfo/bangpypers
