Re: Comparing strings from the back?

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Date	2012-09-13 15:37 -0400
Subject	Re: Comparing strings from the back?
From	Dwight Hutto <dwightdhutto@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.633.1347565065.27098.python-list@python.org> (permalink)

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On Thu, Sep 13, 2012 at 2:39 PM, Prasad, Ramit
<ramit.prasad@jpmorgan.com> wrote:
> Dwight Hutto wrote:
>> Why don' you just time it,eit lops through incrementing thmax input/
>
> What? Without context I have no idea what this means.
>
>
> Ramit

Why don't you read the OP:

Let's assume you're testing two strings for equality.  You've already
done the obvious quick tests (i.e they're the same length), and you're
down to the O(n) part of comparing every character.

I'm wondering if it might be faster to start at the ends of the strings
instead of at the beginning?  If the strings are indeed equal, it's the
same amount of work starting from either end.  But, if it turns out that
for real-life situations, the ends of strings have more entropy than the
beginnings, the odds are you'll discover that they're unequal quicker by
starting at the end.

>

and this one from me:

First include len(string)/2, in order to include starting at the
center of the string, and threading/weaving by 2 processes out.

import timeit

 do the the rest, and see which has the fastest time.> --
>

Why don't take the time to read the OP, and ramit in your head?

Remember that you're in the middle of a conversation where the OP is
following as it goes along, so anyone reading the entire set of
postings should get it.

But for people who just want to jump in, and assume that the only
thing that matters is one piece, without reading the entire content of
the conversation, will always have something out of context for them.

-- 
Best Regards,
David Hutto
CEO: http://www.hitwebdevelopment.com

Thread

Comparing strings from the back? Roy Smith <roy@panix.com> - 2012-09-03 21:54 -0400
  Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-04 12:07 +1000
  Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-04 02:17 +0000
    Re: Comparing strings from the back? Dan Sommers <dan@tombstonezero.net> - 2012-09-03 21:56 -0700
    Re: Comparing strings from the back? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-04 08:50 +0100
    Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-04 18:32 +0200
      Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-04 18:07 +0000
        Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-05 11:17 +0200
      Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-05 07:59 +1000
        Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-05 11:24 +0200
          Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-05 11:43 +0200
            Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-05 14:30 +0000
              Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-05 16:51 +0200
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-05 16:24 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-05 22:47 +0000
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-06 08:33 +0000
                Re: Comparing strings from the back? Dave Angel <d@davea.name> - 2012-09-06 06:07 -0400
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-07 04:06 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-07 19:10 +0000
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-08 00:55 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-08 11:53 +0000
                RE: Comparing strings from the back? "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-09-13 18:39 +0000
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-13 15:37 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-13 20:48 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 00:46 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-13 21:54 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 01:38 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-13 23:06 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 04:03 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-14 01:20 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 04:53 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-14 03:26 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 07:36 -0400
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-14 10:16 +0000
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 07:43 -0400
                RE: Comparing strings from the back? "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-09-14 22:43 +0000
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-14 23:10 -0400
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-16 18:11 -0700
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-17 14:05 +1000
                Re: Comparing strings from the back? alex23 <wuwei23@gmail.com> - 2012-09-16 23:06 -0700
                Re: Comparing strings from the back? Ethan Furman <ethan@stoneleaf.us> - 2012-09-17 13:35 -0700
                Re: Comparing strings from the back? Neil Hodgson <nhodgson@iinet.net.au> - 2012-09-18 09:14 +1000
                Re: Comparing strings from the back? Ethan Furman <ethan@stoneleaf.us> - 2012-09-18 08:12 -0700
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-18 11:55 -0400
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-18 11:59 -0400
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-18 12:17 -0400
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-19 00:47 +0000
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-19 02:20 +1000
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-18 16:40 -0400
                Re: Comparing strings from the back? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-19 00:48 +0100
                Re: Comparing strings from the back? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-13 20:53 +0100
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-13 17:06 -0400
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-14 03:39 +0000
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-14 14:15 +1000
                Re: Comparing strings from the back? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-13 22:17 +0100
                Re: Comparing strings from the back? Dwight Hutto <dwightdhutto@gmail.com> - 2012-09-13 17:35 -0400
                RE: Comparing strings from the back? "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-09-14 21:32 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-07 19:40 +0000
                Re: Comparing strings from the back? Gelonida N <gelonida@gmail.com> - 2012-09-08 17:52 +0200
                Re: Comparing strings from the back? Duncan Booth <duncan.booth@invalid.invalid> - 2012-09-10 08:59 +0000
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-10 13:45 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-10 14:06 +0000
                Re: Comparing strings from the back? Duncan Booth <duncan.booth@invalid.invalid> - 2012-09-11 09:51 +0000
                Re: Comparing strings from the back? Terry Reedy <tjreedy@udel.edu> - 2012-09-11 11:55 -0400
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-11 00:26 +1000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-10 14:32 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-10 14:43 +0000
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-11 00:56 +1000
                Re: Comparing strings from the back? Duncan Booth <duncan.booth@invalid.invalid> - 2012-09-11 09:41 +0000
                Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-06 12:04 +0100
                Re: Comparing strings from the back? Steve Howell <showell30@yahoo.com> - 2012-09-14 17:51 -0700
                Re: Comparing strings from the back? Roy Smith <roy@panix.com> - 2012-09-06 08:13 -0400
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-06 22:29 +1000
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 15:43 +0200
                Re: Comparing strings from the back? Dave Angel <d@davea.name> - 2012-09-06 10:23 -0400
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 16:33 +0200
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 16:42 +0200
                Re: Comparing strings from the back? Dave Angel <d@davea.name> - 2012-09-06 11:54 -0400
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 16:34 +0200
                Re: Comparing strings from the back? Gelonida N <gelonida@gmail.com> - 2012-09-08 17:50 +0200
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 15:37 +0200
                Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-07 00:39 +1000
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 17:36 +0200
                Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-06 17:44 +0200
                Re: Comparing strings from the back? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-07 04:07 +0000
  Re: Comparing strings from the back? Terry Reedy <tjreedy@udel.edu> - 2012-09-04 01:13 -0400
  Re: Comparing strings from the back? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-09-04 08:56 +0100
  Re: Comparing strings from the back? Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2012-09-04 11:58 +0200
  Re: Comparing strings from the back? Neil Hodgson <nhodgson@iinet.net.au> - 2012-09-05 12:18 +1000
    Re: Comparing strings from the back? MRAB <python@mrabarnett.plus.com> - 2012-09-05 03:39 +0100
    Re: Comparing strings from the back? Roy Smith <roy@panix.com> - 2012-09-04 22:48 -0400
    Re: Comparing strings from the back? Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-09-05 16:33 +0200
  Re: Comparing strings from the back? Peter Otten <__peter__@web.de> - 2012-09-05 10:29 +0200
  Re: Comparing strings from the back? Chris Angelico <rosuav@gmail.com> - 2012-09-05 18:33 +1000
  Re: Comparing strings from the back? Peter Otten <__peter__@web.de> - 2012-09-05 11:48 +0200
  Re: Comparing strings from the back? Peter Otten <__peter__@web.de> - 2012-09-05 17:45 +0200
  Re: Comparing strings from the back? Dan Goodman <dg.gmane@thesamovar.net> - 2012-09-10 18:07 +0200
  Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-10 16:33 +0000
  Re: Comparing strings from the back? Dan Goodman <dg.gmane@thesamovar.net> - 2012-09-10 19:32 +0200
  Re: Comparing strings from the back? Dan Goodman <dg.gmane@thesamovar.net> - 2012-09-10 19:44 +0200
  Re: Comparing strings from the back? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2012-09-10 21:52 +0000

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