[Python-Dev] dict.supplement() (was Re: list.shift())
Fred L. Drake, Jr.
Mon, 20 Mar 2000 14:02:48 -0500 (EST)
Peter Funk writes:
> Ouppss... I should have tested this before posting. But currently I use
> the more explicit (and probably slower version) in my code:
The performance is based entirely on the size of each; in the
(probably typical) case of smallish dictionaries (<50 entries), it's
probably cheaper to use a temporary dict and do the update.
For large dicts (on the defaults side), it may make more sense to
reduce the number of objects that need to be created:
target = ...
has_key = target.has_key
for key in defaults.keys():
if not has_key(key):
target[key] = defaults[key]
This saves the construction of len(defaults) 2-tuples.
Fred L. Drake, Jr. <fdrake at acm.org>
Corporation for National Research Initiatives