python new test framework is required. updated in this fork

This kata expects 1 group of zeroes to be contracted to ::, which violates the actual IPv6 spec: when there is only 1 group of zeroes 0 is retained instead of ::.

(This applies to both at the ends and at the middle.)

This kata is a duplicate of https://www.codewars.com/kata/54fa4e210609868fce0002bf

And this kata's test cases are less comprehensive as https://www.codewars.com/kata/5722d87c785220f5780013cf (there are some edge cases that only exists in that kata)

Needs random tests.

I just wanted to say, in the instructions you said "009C:0000:120A can be written as 9C::120A", that's wrong as seen in this RFC : https://datatracker.ietf.org/doc/html/rfc5952#section-4.2.2
You cannot shorten an IPv6 address with only a single zero hextet.

Please use new python test framework.