Nice, here's a O(n) solution

very smart!

Dude, that looks amazing!

So coooool 0-0

x is not False, is always True (only in case when x == False)... it is useful in the case when 'arr' contains True/False .
For example :
sorted([1, 0, 1, 2,False, 0, 1, 3], key= lambda x: x==0)
-->[1, 1, 2, 1, 3, 0, False, 0]

but
sorted([1, 0, 1, 2,False, 0, 1, 3], key= lambda x: x==0 and x is not False)
-->[1, 1, 2, False, 1, 3, 0, 0]

Hope this helps!

Could you please explain why do we have to do it in this kata?

Why "and x is not False"?

I tried this solution without that and it worked.

Very pythonic, not sure if sorting with this lambda is always O(n)

hahahaha i have never been more surprised at an answer. nicely played.

spoiler flag, damn you!... x-/

a little bit joking

This answer is totally meaningless.

Thanks, done (with retrocompatibility for older solutions)