• Not sure howto do this

Question related to mission Non-unique Elements

 

I looked at the "elementary" challenge and I don't know what I am supposed to do. Am I fixing the code. I don't know anything about Python and was hoping I could learn it here but I am completely lost :(

At the bottom it sais Precondition: 0 < len(data) < 1000

What does this mean?

Created at: 2014/09/26 23:42; Updated at: 2014/09/26 23:55
1
Costello