Getting values out of a CSV

Alex Popescu the.mindstorm.mailinglist at gmail.com
Sun Jul 15 18:07:36 CEST 2007


On Jul 15, 3:00 pm, Steve Holden <st... at holdenweb.com> wrote:
> Alex Popescu wrote:
> > On Jul 14, 5:55 am, "Gabriel Genellina" <gagsl-... at yahoo.com.ar>
> > wrote:
> >> So, as always, one should measure in each specific case if optimization is  
> >> worth the pain [...].
>
> > I hope I am somehow misreading the above sentence :-). IMO synonim
> > language contructs
> > should result in the same performance or at least have clear/
> > documented performance.
>
> That's a fine opinion, how would you enforce it? Should we go throught
> he interpreter slowing down the faster to each pair of alternative
> constructs? ;-) It's inevitable there'll be differences in execution
> time between equivalent constructs, and in that case you have to test to
> find the better in your specific situation.
>
> The real issue here is that in 95% or more of the source of most
> programs speed/performance isn't that much of an issue anyway.
>
> > I don't think we really want to see in code something like:
>
> > if threshold:
> >   do_it_with_list_function
> > else:
> >   do_it_with_list_comprehension
>
> This would most certainly be a premature optimization which, as has been
> repeated many times on this list, is the root of much evil in
> programming. As Gabriel mentioned, you only need to do it if it's "worth
> the pain", which in most case it won't be. It isn't worth spending even
> five minutes to shave a minute off the performance of a ten-minute
> program that is only run once a week, for example.
>
> Ultimately we have to be pragmatic: circumstances alter cases, and it's
> usually not worth spending the time to improve execution speed except
> for the most critical parts (the innermost nested loops) of production
> programs.
>
> regards
>   Steve
> --
> Steve Holden        +1 571 484 6266   +1 800 494 3119
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Steve, I fully agree with you (I am a newbie only to Python and not to
programming ;-)).
My point was that this thread may be misleading to newbies, because it
is discussing
corner cases performance of the 2 equivalent language constructs,
while it should
most probably be about the fact that the 2 solutions are equivalent
and the only
difference is probably readability (or maybe something like: list
function is
prefered when there are no additional constraints on the list
comprehension construct).

bests,

./alex
--
.w( the_mindstorm )p.





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