I had the same thing happen to me, it took about three iterations of the "Attempt" button to finally let me pass.

I didn't think that it could be because of the special characters, but I guess it's the only thing that makes sense.

This doesn't work for me if the string is made of special chars...

Thanks! I can't try Python 2, but now I understand :)

By the way my comment included
"This returns "<map at 0x7f0d25564438>"
(just in case someone doesn't understand the question)

Try it in Python 2.7 where map returns a list, not an iterator.

This returns <map at 0x7f096c64e128>
tried it just with:
up_array([4, 3, 2, 5])
Does it really work for others? Why?