I think ideone and/or your editor converts tabs to 8 spaces. Trying a tab indent followed by an 8-space one raises an error in native IPython for me. In any cas

I think ideone and/or your editor converts tabs to 8 spaces. Trying a tab indent followed by an 8-space one raises an error in native IPython for me. In any case, we're using normal CPython compiled to JavaScript, so it's unlikely to change finer points of the behaviour like this.