isn't id better to count? since it's non nullable e usually its the primary key witch makes guaranties the index?

I'm still learn, so i'm sorry if that makes no sense

I need to stop using a lot of lines, this one resumes it all.

Very clean solution

Oh! If only I'd actually written the math down on a piece of paper.
That is so elegant :)

if it requires please do not hesitate, for example a formula or bulit in fuction the goal is to learn

Obsolete issue, closing

good solution

the python reads all the line becaue all in same line and same interpretting so python read it if it another line there would be an eror

nice

I get where you are coming from...but could you please elaborate on what principles of a pure function it violates?
I may be missing something - but doesn't it comply with not having side effects (i.e. nothing mutated), and it would produce the same result every time given the same inputs? Is it because of the 'lines' param being a reference variable, which could be changed outside of the method?