[Tutor] List comprehension question

[Alan Gauld]

"Steven D'Aprano" <steve at pearwood.info> wrote

> I'm going to be pedantic here... but to quote the Middleman, 
> specificity is the soul of all good communication.

Be pedantic! :-)
I really liked the explanation although I already sort of knew most of 
it.
But there were a few nuggets in there I'd missed, like range() being
a type all of its own.

But one, slightly off-topic, question:

> def proper_divisors(n):
>     return sum(x for x in range(1, int(math.sqrt(n))) if n%x == 0)
>

Why use math.sqrt() instead of just using the ** operator?

     return sum(x for x in range(1, int(n**0.5)) if n%x == 0)

I'd have expected ** to be significantly faster than calling the
function, and given this is a performance tweak...?

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/