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Groups > comp.lang.python > #62996

Re: Blog "about python 3"

From Terry Reedy <tjreedy@udel.edu>
Subject Re: Blog "about python 3"
Date 2014-01-02 13:37 -0500
References (4 earlier) <mailman.4748.1388478161.18130.python-list@python.org> <52c29416$0$29987$c3e8da3$5496439d@news.astraweb.com> <mailman.4753.1388499265.18130.python-list@python.org> <roy-4C0A2F.10412731122013@news.panix.com> <52C5A3BA.5080700@chamonix.reportlab.co.uk>
Newsgroups comp.lang.python
Message-ID <mailman.4805.1388687856.18130.python-list@python.org> (permalink)

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On 1/2/2014 12:36 PM, Robin Becker wrote:

> I just spent a large amount of effort porting reportlab to a version
> which works with both python2.7 and python3.3. I have a large number of
> functions etc which handle the conversions that differ between the two
> pythons.

I am imagine that this was not fun.

[For those who do not know, reportlab produces pdf documents.]

> For fairly sensible reasons we changed the internal default to use
> unicode rather than bytes.

Do you mean 'from __future__ import unicode_literals'?

Am I correct in thinking that this change increases the capabilities of 
reportlab? For instance, easily producing an article with abstracts in 
English, Arabic, Russian, and Chinese?

 > After doing all that and making the tests
> compatible etc etc I have a version which runs in both and passes all
> its tests. However, for whatever reason the python 3.3 version runs slower.

Python 3 is slower in some things, like integer arithmetic with small ints.

> 2.7 Ran 223 tests in 66.578s
>
> 3.3 Ran 223 tests in 75.703s
>
> I know some of these tests are fairly variable, but even for simple
> things like paragraph parsing 3.3 seems to be slower. Since both use
> unicode internally it can't be that can it, or is python 2.7's unicode
> faster?

The new unicode implementation in 3.3 is faster for some operations and 
slower for others. It is definitely more space efficient, especially 
compared to a wide build system. It is definitely less buggy, especially 
compared to a narrow build system.

Do your tests use any astral (non-BMP) chars? If so, do they pass on 
narrow 2.7 builds (like on Windows)?

> So far the superiority of 3.3 escapes me,

For one thing, indexing and slicing just works on all machines for all 
unicode strings. Code for 2.7 and 3.3 either a) does not index or slice, 
b) does not work for all text on 2.7 narrow builds, or c) has extra 
conditional code only for 2.7.

-- 
Terry Jan Reedy

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Thread

Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-30 19:41 +0000
  Re: Blog "about python 3" Steven D'Aprano <steve@pearwood.info> - 2013-12-30 20:49 +0000
    Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-30 21:29 +0000
    Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2013-12-30 14:38 -0800
    Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2013-12-31 12:09 +1100
    Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 04:38 +0000
    Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2013-12-31 15:44 +1100
    Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2013-12-30 20:33 -0800
    Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 04:59 +0000
    Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 08:22 +0000
      Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-12-31 20:53 +1100
        Re: Blog "about python 3" Antoine Pitrou <solipsis@pitrou.net> - 2013-12-31 14:13 +0000
          Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2013-12-31 10:41 -0500
            Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-01 02:54 +1100
            Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-31 15:55 +0000
            Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-02 17:36 +0000
              Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-03 15:49 +1100
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-03 04:01 -0500
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-03 02:10 -0800
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-03 21:24 +1100
                Re: Blog "about python 3" Ethan Furman <ethan@stoneleaf.us> - 2014-01-03 08:56 -0800
                Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 12:28 +0000
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-03 09:57 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-04 02:32 +1100
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-03 17:00 -0500
                Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-04 04:04 +0000
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-04 08:55 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 01:17 +1100
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-04 11:10 -0800
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-04 17:46 -0500
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-05 06:23 -0800
                Re: Blog "about python 3" Ned Batchelder <ned@nedbatchelder.com> - 2014-01-05 10:20 -0500
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:14 -0500
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-07 05:34 -0800
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-07 09:54 -0500
                Re: Blog "about python 3" Tim Delaney <timothy.c.delaney@gmail.com> - 2014-01-08 09:38 +1100
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-07 19:02 -0500
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-08 01:59 -0800
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-08 14:26 -0500
                Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-08 20:04 +0000
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:48 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 10:28 +1100
                Re: Blog "about python 3" Ned Batchelder <ned@nedbatchelder.com> - 2014-01-04 12:51 -0500
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 13:27 +1100
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 13:32 +1100
                Re: Blog "about python 3" MRAB <python@mrabarnett.plus.com> - 2014-01-05 02:41 +0000
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-04 22:20 -0500
                Re: Blog "about python 3" Rustom Mody <rustompmody@gmail.com> - 2014-01-05 10:12 +0530
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 00:11 -0500
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 17:28 +1100
                Re: Blog "about python 3" Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-01-05 14:05 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 15:01 +1100
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 11:34 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 03:51 +1100
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 12:09 -0500
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-06 11:42 +1100
                Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-05 17:56 -0500
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 10:59 +1100
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-06 12:23 +1100
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-06 12:54 +1100
                Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-06 05:53 +0000
                Re: Blog "about python 3" Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-01-05 00:00 -0800
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 23:28 +1100
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 23:48 +1100
                Re: Blog "about python 3" Roy Smith <roy@panix.com> - 2014-01-05 11:10 -0500
                Re: Blog "about python 3" Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-01-05 13:51 -0500
            Re: Blog "about python 3" David Hutto <dwightdhutto@gmail.com> - 2014-01-02 13:25 -0500
            Re: Blog "about python 3" Terry Reedy <tjreedy@udel.edu> - 2014-01-02 13:37 -0500
            Re: Blog "about python 3" Antoine Pitrou <solipsis@pitrou.net> - 2014-01-02 23:57 +0000
            Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 10:32 +0000
            Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 11:14 +0000
              Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-04 05:52 -0800
                Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-01-05 13:41 +1100
                Re: Blog "about python 3" Chris Angelico <rosuav@gmail.com> - 2014-01-05 13:54 +1100
                Re: Blog "about python 3" wxjmfauth@gmail.com - 2014-01-05 02:39 -0800
            Re: Blog "about python 3" Robin Becker <robin@reportlab.com> - 2014-01-03 11:37 +0000
            Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-04 07:30 +0000
        Re: Blog "about python 3" Johannes Bauer <dfnsonfsduifb@gmx.de> - 2014-01-05 13:14 +0100
          Re: Blog "about python 3" Stefan Behnel <stefan_ml@behnel.de> - 2014-01-05 14:55 +0100
        Re: Blog "about python 3" Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-01-05 13:10 +0000
    Re: Blog "about python 3" Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-12-31 20:04 +1100
    Re: Blog "about python 3" Devin Jeanpierre <jeanpierreda@gmail.com> - 2013-12-30 20:25 -0800

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