Marc 'BlackJack' Rintsch wrote:
On Wed, 24 Dec 2008 03:23:00 -0500, python wrote:
collection, I don't see the advantage of using an iterator or a list.
I'm sure I'm missing a subtle point here :)
`keys()` creates a list in memory, `iterkeys()` does not. With
``set(dict.keys())`` there is a point in time where the dictionary, the
list, and the set co-exist in memory. With ``set(dict.iterkeys())`` only
the set and the dictionary exist in memory.
If you can, consider using 3.0 in which d.keys() is a set-like view of
the keys of d. Same for d.values and d.items. The time and space to
create such is O(1), I believe. since they are just alternate read-only
interfaces to the internal dict storage. There is not even a separate
set until you do something like intersect d1.keys() with d2.keys() or
d1.keys() - d2.keys(). I think this is an under-appreciated feature of
3.0 which should be really useful with large dicts.
tjr
--
http://mail.python.org/mailman/listinfo/python-list
