On Jan 22, 1:34 pm, Paddy <[EMAIL PROTECTED]> wrote: > On Jan 22, 5:34 am, George Sakkis <[EMAIL PROTECTED]> wrote: > > > > > On Jan 22, 12:15 am, Paddy <[EMAIL PROTECTED]> wrote: > > > > On Jan 22, 3:20 am, Alan Isaac <[EMAIL PROTECTED]> wrote:> I want to > > > generate sequential pairs from a list. > > > <<snip>> > > > > What is the fastest way? (Ignore the import time.) > > > > 1) How fast is the method you have? > > > 2) How much faster does it need to be for your application? > > > 3) Are their any other bottlenecks in your application? > > > 4) Is this the routine whose smallest % speed-up would give the > > > largest overall speed up of your application? > > > I believe the "what is the fastest way" question for such small well- > > defined tasks is worth asking on its own, regardless of whether it > > makes a difference in the application (or even if there is no > > application to begin with). > > Hi George, > You need to 'get it right' first.
For such trivial problems, getting it right alone isn't a particularly high expectation. > Micro optimizations for speed > without thought of the wider context is a bad habit to form and a time > waster. The OP didn't mention anything about the context; for all we know, this might be a homework problem or the body of a tight inner loop. There is this tendency on c.l.py to assume that every optimization question is about a tiny subproblem of a 100 KLOC application. Without further context, we just don't know. > If the routine is all that needs to be delivered and it does not > perform at an acceptable speed then find out what is acceptable > and optimise towards that goal. My questions were set to get > posters to think more about the need for speed optimizations and > where they should be applied, (if at all). I don't agree with this logic in general. Just because one can solve a problem by throwing a quick and dirty hack with quadratic complexity that happens to do well enough on current typical input, it doesn't mean he shouldn't spend ten or thirty minutes more to write a proper linear time solution, all else being equal or at least comparable (elegance, conciseness, readability, etc.). Of course it's a tradeoff; spending a week to save a few milliseconds on average is usually a waste for most applications, but being a lazy keyboard banger writing the first thing that pops into mind is not that good either. George -- http://mail.python.org/mailman/listinfo/python-list
