Sure thing.

Ok, I see where is my problem. I wrote solution for Python3, where range() function returns range object. In python2 that function returns list. Thanks for help

I'm not sure I understand your question. For one thing, in Python a list is an object (practically everything is an object in Python) so I don't understand this objection. As far as how this works, all it does is call the "range" function:

https://docs.python.org/2/library/functions.html#range

Have you tried reading the relevant documentation? If so, maybe you could say a little bit more about what you find confusing. You could also try asking for help on the Codewars gitter:

https://gitter.im/Codewars/codewars.com/kata-solving-help

how does this work? This function returns range object instead of list. Am I missing something?