OrderedSet() 是否还有 O(1) 的搜索参数？

Question

I have heard that when you perform an in operator on a list it has to search through O(n) objects while if you do it on a set it has to search through O(1) objects. To see what I mean go here . Does this still apply to OrderedSet ?

Answer 1

Which OrderedSet are you talking about? At this time (Python 3.8.3), there is not OrderedSet in the standard library.

Typically , OrderedSet implementations will implement __contains__ by delegating to the underlying set . So it will have the algorithmic complexity you would expect.