Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
I found the answer myself:
Language Versions
Python 2.7.6 and 3.4.3 are supported.
Hope this helps other people :)
Is codewars running a Python version previous to Python 3? That will explain this issue.
This comment is hidden because it contains spoiler information about the solution