Re: String performance regression from python 3.2 to 3.3

From	Terry Reedy <tjreedy@udel.edu>
Subject	Re: String performance regression from python 3.2 to 3.3
Date	2013-03-13 22:35 -0400
References	(1 earlier) <a1a6394a-e9c7-407b-9f6d-ff44de1b65de@y2g2000pbg.googlegroups.com> <eabe27a9-099a-4e2c-92fb-bdf3819c2561@kw7g2000pbb.googlegroups.com> <mailman.3259.1363172350.2939.python-list@python.org> <ee2062d1-658a-4bf5-8a56-5fe9c0991bef@o9g2000pbt.googlegroups.com> <CAPTjJmqEAdff+cH2NWtp0oX1ZvFzQJqPxNm=c8=XAm3j+GV1uQ@mail.gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.3283.1363228557.2939.python-list@python.org> (permalink)

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On 3/13/2013 7:43 PM, Chris Angelico wrote:
> On Thu, Mar 14, 2013 at 3:49 AM, rusi <rustompmody@gmail.com> wrote:
>
>> This assumes that there are only three choices:
>> - narrow build that is buggy (surrogate pairs for astral characters)
>> - wide build that is 4-fold space inefficient for wide variety of
>> common (ASCII) use-cases
>> - flexible string engine that chooses a small tradeoff of space
>> efficiency over time efficiency.

Wrong. Python almost certainly runs faster with the new string 
representation. This has been explained previously more than once.

>> There is a fourth choice: narrow build that chooses to be partial over
>> being buggy. ie when an astral character is encountered, an exception
>> is thrown rather than trying to fudge it into a 16-bit
>> representation.

This is what tcl/tk does, and it is a dammed nuisance. Completely 
unacceptible for Python's string type.
...
> It's complexity cost, though, and people would need to know when it
> would be worth giving Python that switch to change its string format.
> Plus, every C extension would need to cope with both formats. I
> personally doubt it'd be worth it, but if you want to knock together a
> patched CPython and get some timing stats, I'm sure this list or
> python-dev will be happy to discuss the matter. :)

I presume the smiley indicates that you know that python developers are 
too busy with real problems to have any interest in bogus solutions to 
bogus problems.

-- 
Terry Jan Reedy

Thread

A reply for rusi (FSR) jmfauth <wxjmfauth@gmail.com> - 2013-03-13 02:36 -0700
  Re: A reply for rusi (FSR) rusi <rustompmody@gmail.com> - 2013-03-13 03:07 -0700
    String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-13 03:11 -0700
      Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-13 21:59 +1100
        Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-13 09:49 -0700
          Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-14 10:43 +1100
          Re: String performance regression from python 3.2 to 3.3 MRAB <python@mrabarnett.plus.com> - 2013-03-14 00:52 +0000
          Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-14 11:55 +1100
          Re: String performance regression from python 3.2 to 3.3 MRAB <python@mrabarnett.plus.com> - 2013-03-14 02:01 +0000
            Re: String performance regression from python 3.2 to 3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-14 04:05 +0000
              Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-14 17:47 +1100
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-14 03:48 -0700
                Re: String performance regression from python 3.2 to 3.3 Terry Reedy <tjreedy@udel.edu> - 2013-03-14 19:14 -0400
                Re: String performance regression from python 3.2 to 3.3 Terry Reedy <tjreedy@udel.edu> - 2013-03-14 20:48 -0400
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-15 10:07 -0700
                RE: String performance regression from python 3.2 to 3.3 Andriy Kornatskyy <andriy.kornatskyy@live.com> - 2013-03-15 21:04 +0300
          Re: String performance regression from python 3.2 to 3.3 Terry Reedy <tjreedy@udel.edu> - 2013-03-13 22:35 -0400
          Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-14 17:21 +1100
        Re: String performance regression from python 3.2 to 3.3 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-13 18:42 +0100
          Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-14 11:19 +1100
            Re: String performance regression from python 3.2 to 3.3 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-16 03:44 +0100
              Re: String performance regression from python 3.2 to 3.3 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-03-16 03:56 +0000
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-15 21:26 -0700
                Re: String performance regression from python 3.2 to 3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-16 08:47 +0000
                Re: String performance regression from python 3.2 to 3.3 Neil Hodgson <nhodgson@iinet.net.au> - 2013-03-17 09:00 +1100
                Re: String performance regression from python 3.2 to 3.3 Roy Smith <roy@panix.com> - 2013-03-16 18:10 -0400
              Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-16 14:59 +1100
                Re: String performance regression from python 3.2 to 3.3 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-16 05:12 +0100
                Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-16 15:20 +1100
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-15 22:21 -0700
              Re: String performance regression from python 3.2 to 3.3 Chris Angelico <rosuav@gmail.com> - 2013-03-16 15:09 +1100
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-15 21:35 -0700
                Re: String performance regression from python 3.2 to 3.3 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-03-16 04:56 +0000
                Re: String performance regression from python 3.2 to 3.3 Terry Reedy <tjreedy@udel.edu> - 2013-03-16 01:05 -0400
                Re: String performance regression from python 3.2 to 3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-16 05:38 +0000
                Re: String performance regression from python 3.2 to 3.3 Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-16 05:25 +0000
                Re: String performance regression from python 3.2 to 3.3 Roy Smith <roy@panix.com> - 2013-03-16 09:29 -0400
                Re: String performance regression from python 3.2 to 3.3 rusi <rustompmody@gmail.com> - 2013-03-16 09:39 -0700
                Re: String performance regression from python 3.2 to 3.3 Roy Smith <roy@panix.com> - 2013-03-16 14:00 -0400
                Re: String performance regression from python 3.2 to 3.3 jmfauth <wxjmfauth@gmail.com> - 2013-03-16 13:42 -0700
  Re: A reply for rusi (FSR) Chris Angelico <rosuav@gmail.com> - 2013-03-13 21:32 +1100

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