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Groups > comp.lang.python > #104370

Re: Pyhon 2.x or 3.x, which is faster?

From Michael Torrie <torriem@gmail.com>
Newsgroups comp.lang.python
Subject Re: Pyhon 2.x or 3.x, which is faster?
Date 2016-03-08 17:42 -0700
Message-ID <mailman.61.1457484162.15725.python-list@python.org> (permalink)
References (3 earlier) <nbjp1e$jhv$1@dont-email.me> <nbjrjm$m16$1@gioia.aioe.org> <nbjvas$h22$1@dont-email.me> <mailman.17.1457364684.10335.python-list@python.org> <nbkhei$dg6$1@dont-email.me>

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On 03/07/2016 11:34 AM, BartC wrote:
> (I'm quite pleased with my version: smaller, faster, works on all the 
> Pythons, supports all 3 colour formats and no decoding bugs that I'm 
> aware of, and it's the first Python program I've written that does 
> something useful.)

I think you should be commended for writing it.  It may not be perfect,
nor is it necessarily "Pythonic" but you had fun doing it.  I hope you
aren't discouraged by the criticism of your code.

I hacked on it a bit, and it only took about a minute to change from
using arrays to immutable byte strings.  The only problem with that was
what I noted in my other reply.  That is that indexing a Python 2 string
gives a different result than indexing a Python 3 byte string.  I'm not
sure what kind of logic should be used to efficiently judge between
Python 2 and 3, and modify the answer accordingly.  In Python 2 I can
simply do "ord(fs.data[fs.pos])".  In Python 3 it's just
"fs.data[fs.pos]".  I'm not sure what kind of speed up using a normal
string provides vs the array.  But it has to be more a bit faster.

I suppose if others want to direct you in a more Pythonic path, they
could take your code and turn it into something that is more idiomatic
(and perhaps faster).  I may take a crack at it.

If it were me I think I'd make your jpeg decoder into it's own class,
and have it operate on any iterable input, be it an open file or
something else.  That may be actually slower though, but more pythonic.

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Thread

Pyhon 2.x or 3.x, which is faster? Tony van der Hoff <tony@vanderhoff.org> - 2016-03-06 11:34 +0000
  Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-07 01:41 +1100
    Re: Pyhon 2.x or 3.x, which is faster? Tony van der Hoff <tony@vanderhoff.org> - 2016-03-07 10:45 +0000
    Re: Pyhon 2.x or 3.x, which is faster? Andrew Jaffe <a.h.jaffe@gmail.com> - 2016-03-07 11:54 +0000
    Re: Pyhon 2.x or 3.x, which is faster? Terry Reedy <tjreedy@udel.edu> - 2016-03-07 17:33 -0500
  Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 11:02 +0000
    Re: Pyhon 2.x or 3.x, which is faster? Marko Rauhamaa <marko@pacujo.net> - 2016-03-07 13:11 +0200
      Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 11:38 +0000
        Re: Pyhon 2.x or 3.x, which is faster? Fabien <fabien.maussion@gmail.com> - 2016-03-07 13:19 +0100
          Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 13:25 +0000
            Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 02:31 +1100
              Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 18:34 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 06:10 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 20:19 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 07:47 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-07 22:39 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 10:40 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 00:22 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 00:43 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 11:45 +1100
                Re: Pyhon 2.x or 3.x, which is faster? MRAB <python@mrabarnett.plus.com> - 2016-03-08 00:47 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2016-03-07 20:29 -0500
                Re: Pyhon 2.x or 3.x, which is faster? Terry Reedy <tjreedy@udel.edu> - 2016-03-07 22:51 -0500
                Re: Pyhon 2.x or 3.x, which is faster? Michael Torrie <torriem@gmail.com> - 2016-03-08 17:34 -0700
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 13:01 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-09 11:38 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-08 11:05 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 01:00 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 01:12 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 01:47 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 02:45 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 11:09 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 16:09 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 19:15 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 20:44 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 22:38 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 10:59 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-09 08:40 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 12:02 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-09 21:13 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 23:14 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-09 23:35 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 00:58 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 12:28 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-10 07:30 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 11:50 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-10 12:15 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 12:47 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-11 00:08 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 14:22 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-10 19:26 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-11 16:29 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-11 18:57 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-11 21:59 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-11 22:24 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-12 16:59 +1100
                Re: Pyhon 2.x or 3.x, which is faster? alister <alister.ware@ntlworld.com> - 2016-03-12 10:06 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-12 10:31 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-12 10:51 +0000
                Re: Pyhon 2.x or 3.x, which is faster? alister <alister.ware@ntlworld.com> - 2016-03-12 15:36 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-13 14:22 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-12 10:34 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-12 21:40 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-11 07:07 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-11 16:06 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-11 16:36 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-10 13:18 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-11 00:30 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-10 13:46 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-10 18:43 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 18:55 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 12:59 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 12:19 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 10:38 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-03-09 23:48 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 11:03 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-03-10 02:38 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 14:43 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 01:30 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-10 13:29 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-10 14:32 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 13:45 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-10 11:21 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 12:23 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 01:33 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-08 12:38 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 12:40 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 02:02 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Ben Finney <ben+python@benfinney.id.au> - 2016-03-08 13:28 +1100
                Re: Pyhon 2.x or 3.x, which is faster? MRAB <python@mrabarnett.plus.com> - 2016-03-08 02:47 +0000
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 11:15 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-08 13:45 +0200
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 12:09 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Terry Reedy <tjreedy@udel.edu> - 2016-03-07 22:39 -0500
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 03:48 +0000
                What will I get when reading from a file? (was: Pyhon 2.x or 3.x, which is faster?) Ben Finney <ben+python@benfinney.id.au> - 2016-03-08 11:09 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-08 13:12 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 11:53 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 10:28 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 00:09 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-09 11:36 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2016-03-08 21:03 -0500
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 03:07 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Serhiy Storchaka <storchaka@gmail.com> - 2016-03-08 14:48 +0200
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-08 12:34 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-08 12:49 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Serhiy Storchaka <storchaka@gmail.com> - 2016-03-08 15:05 +0200
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-08 12:19 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 01:41 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-03-08 15:40 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 13:49 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 16:15 +0000
                Re: Pyhon 2.x or 3.x, which is faster? wxjmfauth@gmail.com - 2016-03-08 09:23 -0800
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-08 19:02 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 11:04 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 01:28 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 13:18 +1100
                Re: Pyhon 2.x or 3.x, which is faster? wxjmfauth@gmail.com - 2016-03-09 02:11 -0800
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 14:03 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 01:11 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 14:39 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 01:54 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 02:33 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 02:58 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-03-09 14:56 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 02:28 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 01:57 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Chris Angelico <rosuav@gmail.com> - 2016-03-10 02:04 +1100
                Re: Pyhon 2.x or 3.x, which is faster? BartC <bc@freeuk.com> - 2016-03-09 16:53 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 01:54 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-03-09 15:06 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Tim Golden <mail@timgolden.me.uk> - 2016-03-09 15:15 +0000
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 02:38 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Terry Reedy <tjreedy@udel.edu> - 2016-03-09 10:42 -0500
                Re: Pyhon 2.x or 3.x, which is faster? wxjmfauth@gmail.com - 2016-03-09 09:04 -0800
                Re: Pyhon 2.x or 3.x, which is faster? Marko Rauhamaa <marko@pacujo.net> - 2016-03-09 08:08 +0200
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-09 22:52 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Marko Rauhamaa <marko@pacujo.net> - 2016-03-09 14:53 +0200
                Re: Pyhon 2.x or 3.x, which is faster? Steven D'Aprano <steve@pearwood.info> - 2016-03-10 03:53 +1100
                Re: Pyhon 2.x or 3.x, which is faster? Michael Torrie <torriem@gmail.com> - 2016-03-08 17:42 -0700
        Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-08 02:53 +0000
    Re: Pyhon 2.x or 3.x, which is faster? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-07 19:02 +0000

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