Solved it thanks to your comment.

Thank you, this comment should be added to the description

I don't think he was serious with that solution

because it doesn't "consume" what would otherwise be the second group. See:

    test.assert_equals(insert_dash(13579),'1-3-5-7-9')

I think they prefer to avoid it because its easy to get lost in it ....

But it's a nice feature! I really love it

Done.

manual notification, see above

I solved this kata thanks to your comment, thank you.

Ranks can't be changed!

Uh, no, if the input is "aba" the answer should be "A-Bb-Aaa".

Did you ever figure out why the 2nd group of N's are copying the first set? I'm running into this issue as well. Thanks!

that is true, not working right tests now, , sample test differ real tests, change sample test or instruction

The tests are fine, your solution is wrong:

test.assert_equals(accum("ZpglnRxqenU"), "Z-Pp-Ggg-Llll-Nnnnn-Rrrrrr-Xxxxxxx-Qqqqqqqq-Eeeeeeeee-Nnnnnnnnnn-Uuuuuuuuuuu")

Your code produces this instead:

"Z-Pp-Ggg-Llll-Nnnnn-Rrrrrr-Xxxxxxx-Qqqqqqqq-Eeeeeeeee-Nnnnn-Uuuuuuuuuuu"

Note the second group of N's length.