Large Dictionaries

[Sion Arrowsmith]

Maric Michaud  <maric at aristote.info> wrote:
>I don't see a use case where a python programmer should need a
>dictionnary "that will be probably big" but can't predict what keys will be
>in.

I've recently been working on an app with precisely this
characteristic, although there were enough other bottlenecks that the
cost of growing the dict as needed was irrelevant. (Read ~2m items
from csv file, compare them with items in a database and populate
assorted dictionaries based on the result of that comparison for
subsequent processing. You can make a reasonable guess, and have a
definite upper bound, on the sizes of the dictionaries cheaply right
at the start, but you don't know what the keys in each are going to be
until you discover them through the comparison of file and DB.)

-- 
\S -- siona at chiark.greenend.org.uk -- http://www.chaos.org.uk/~sion/
  ___  |  "Frankly I have no feelings towards penguins one way or the other"
  \X/  |    -- Arthur C. Clarke
   her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump