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.

In your solution, if you remove the 'Walrus operator',
nothing will change.
Everything worked,
and will continue to work without the 'Walrus operator'

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

It actually is

isinstance has no need here

'Walrus operator' capable make this solution more efficient oneliner. Open for arguments...

Neither best practice or clever. Same goes for the other solutions which are highly rated.

This was insighful

thank you, appreciate it.