my favourite solution so far. Concise but still super readable

hmm clever:)))

Is there anything gained by the first part of the if-expression

v in array[:i]

Thanks for the quick reply mate.
Learning a lot from your comments and solutions, as I'm sure many others are. Keep it up bro. :)

yes, but nothing significant. Here it's more about reducing the typing (no variable declaration)

It is creating a formated string. Here is a good video on the process:

https://www.youtube.com/watch?v=nghuHvKLhJA

#11b35/3qb:0z:vV

it is the tradeoff for using a scrited language. it is almost impossible to do
anything without headers in c.

I feel you bro

I like your answer.it is easy to understand.

Better to add a last dot to the 'sentence', you will avoid an error for the empty given string ;)

Wow, learning new code everyday

If description doesn't say otherwise then using already existing functions is pretty good approach. In any case everyone is free in ways of solving.

this is technically legal, and elegant, and the authors can't be faulted for using this because it wasn't prohibited, but it defeats the purpose of the kata if you can just use a built in string method at least in my mind.