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Groups > comp.lang.python > #104296

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

From Dennis Lee Bieber <wlfraed@ix.netcom.com>
Newsgroups comp.lang.python
Subject Re: Pyhon 2.x or 3.x, which is faster?
Date 2016-03-07 20:29 -0500
Organization IISS Elusive Unicorn
Message-ID <mailman.19.1457400559.15725.python-list@python.org> (permalink)
References (8 earlier) <nbknir$avu$1@dont-email.me> <mailman.49.1457383632.10335.python-list@python.org> <nbkvq2$j5s$1@dont-email.me> <mailman.3.1457394034.15725.python-list@python.org> <nbl5po$bfo$1@dont-email.me>

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On Tue, 8 Mar 2016 00:22:06 +0000, BartC <bc@freeuk.com> declaimed the
following:

>On 07/03/2016 23:40, Chris Angelico wrote:
>> On Tue, Mar 8, 2016 at 9:39 AM, BartC <bc@freeuk.com> wrote:
>
>>> I'm using it because this kind of file reading in Python is a mess. If I do
>>> a read, will I get a string, a byte sequence object, a byte-array, or
>>> array-array, or what?
>>
>> Uhh.... you'll get either a text string or a byte string, depending on
>> whether you opened the file as text or binary. Where's the mess?
>
>(Is a byte string the same as a byte array? Is a byte array the same as 
>an array.array? If I remove this line from my code, where 'data' has 
>just been read from a file:

	In Python 3, text strings are Unicode (in current versions they will be
1, 2, or 4 bytes per character, depending on the "worst" character in the
string... If everything is ASCII or ISO-Latin-1, a text string will be one
byte per character). In Python 2, text strings are ALWAYS one byte per
character (resulting in garbage if the real data is unicode). In Python 2,
you have to explicitly ask that text be parsed as Unicode; conversely,
Python 3 requires you to explicitly ask for binary bytes.

	In Python 2 you have to use bytearray() to create a "byte array". Byte
array is mutable -- you can change values at each position without having
to decompose and recompose the whole. Text strings are not mutable.


>>> stng = "This is the end of the World"
>>> ba = bytearray(stng)
>>> ba
bytearray(b'This is the end of the World')
>>> stng[10] = "q"
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
TypeError: 'str' object does not support item assignment
>>> ba[10] = "q"
>>> stng
'This is the end of the World'
>>> ba
bytearray(b'This is thq end of the World')
>>> 
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

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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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