• For the example [1,2,3,4,5] my code works fine

 

I would like to give some feedback about ...

From: https://py.checkio.org/mission/non-unique-elements/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2943.0 Safari/537.36
Created at: Feb. 5, 2017, 7:29 p.m.; Updated at: Feb. 6, 2017, 3:35 p.m.
ex.py