That is one viable solution yes.

Added in latest fork

This warning doesn't show anymore currently (using Python 3.11).

Ditto

The table (not the explanation) in this comment was very helpful to me:

https://www.codewars.com/kata/5886cab0a95e17e61600009d/discuss#5c1b423116537c607b0000f3

Can you explain for me, cause i can't understand that description.

This solution always returns a new object

fixed (Python)

Can confirm that caps lock on european keyboard behaves like permanently pressing shift key. This means caps lock and shift key at once negate each other.

The description should say "caps lock only matters to letters". From the tests we only know it doesn't apply to numbers but have to find out ourselves about special characters like comma or apostrophe.

Haha ok thank you I got it. But still it's quite hard for 7 kyu. I'm excited to see the other solutions.
/edit Ok if you got some experience in code golfing it looks much easier.

35 is too hard for 7 kyu. It took quite some time to figure out the shortest formula and then I can't get below 36 :-/

how is this best practice?

This is hard because the description is misleading with all that friendship stuff.
It should simply say that "numbers are in the same clan if they have the same subset of divisors (from the list). How many clans are there?"