Testing for an empty dictionary in Python
D'Arcy J.M. Cain
darcy at druid.net
Sun Mar 23 11:52:30 EDT 2008
On Sun, 23 Mar 2008 08:53:02 -0700
John Nagle <nagle at animats.com> wrote:
> What's the cheapest way to test for an empty dictionary in Python?
>
> if len(dict.keys() > 0) :
>
> is expensive for large dictionaries, and makes loops O(N^2).
Try this:
if dict:
It should be faster as it only checks whether or not there are
any members and does not run keys() or len() on the dictionary. Of
course, you should test it.
--
D'Arcy J.M. Cain <darcy at druid.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
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