how to avoid checking the same condition repeatedly ?

[Chris Angelico]

On Tue, Oct 29, 2013 at 5:14 PM, Peter Cacioppi
<peter.cacioppi at gmail.com> wrote:
> Nobody (yes, his name is Nobody) said:
>
> "If you're sufficiently concerned about performance that you're willing to
> trade clarity for it, you shouldn't be using Python in the first place."
>
> I don't think it's correct to imply that people very concerned about performance should not use Python. (And I agree, Nobody implied that ;)

No, I don't think he implied that. You can care about performance
while still putting code clarity as a higher priority :) If you
actually profile and find that something-or-other is a bottleneck,
chances are you can break it out into a function with minimal loss of
clarity, and then reimplement that function in C (maybe wielding
Cython for the main work). That doesn't compromise clarity.
Duplicating a loop to hoist a condition _does_. Of course, in C, you
can let the compiler do it for you, but Python can't be sure that it's
as constant as you think, so it can't be changed.

ChrisA