Why is dictionary.keys() a list and not a set?
duncan.booth at invalid.invalid
Thu Nov 24 10:39:59 CET 2005
bonono at gmail.com wrote:
>> Consider a dictionary with one million items. The following operations
>> k = d.keys()
>> v = d.values()
>> creates two list objects, while
>> i = d.items()
>> creates just over one million objects. In your "equivalent" example,
> Sorry. I lose you here. Could you explain in detail what do you mean by
> "two list objects" vs one million objects ?
It should be fairly clear. 'd.keys()' creates one new object (a list).
'd.items()' creates a list of tuples, so that is one new list and one
million new tuples.
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