Sure, you could do that, but that would add a second full (unnecessary) pass over the input list arr whereas just calculating the number of zeros from the results of the first pass adds only constant time.

The same as my solution but what's that ominous isinstance(i, bool) for?

what the use of the isinstance here buddy ?

omg im so sorry i'll use it next time bro. thanks for the reminder

Please use spoiler flag next time.

There's definitely no need for isinstance as we're only checking for 1

It actually is

isinstance has no need here

This was insighful

thank you, appreciate it.

Oh stop please. It is incorrect. Function should get argument whith id and should return it with the same id. This solution changed the id. So bad

I think my solution is much clearer than this

what? it's 5 kata example? its very-very easy for 5 kata