Chris Angelico wrote: > On Thu, Jul 25, 2013 at 5:04 PM, Steven D'Aprano > <steve+comp.lang.pyt...@pearwood.info> wrote: >> - Views support efficient (O(1) in the case of keys) membership testing, >> which neither iterkeys() nor Python2 keys() does. > > To save me the trouble and potential error of digging through the > source code: What's the complexity of membership testing on > values/items? Since you're calling it "efficient" it must be better > than O(n) which the list form would be, yet it isn't O(1) or you > wouldn't have qualified "in the case of keys". Does this mean > membership testing of the values and items views is O(log n) in some > way, eg a binary search?
keys() and items() is O(1); both look up the key in the dictionary and items() then proceeds to compare the value. values() is O(n). -- http://mail.python.org/mailman/listinfo/python-list
