Re: Python 3.2 has some deadly infection

References	(16 earlier) <87tx7z5hvw.fsf@elektro.pacujo.net> <mailman.10815.1402062359.18130.python-list@python.org> <87egz25dsd.fsf@elektro.pacujo.net> <mailman.10818.1402066977.18130.python-list@python.org> <87a99q5a08.fsf@elektro.pacujo.net>
Date	2014-06-07 01:50 +1000
Subject	Re: Python 3.2 has some deadly infection
From	Chris Angelico <rosuav@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.10820.1402069852.18130.python-list@python.org> (permalink)

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On Sat, Jun 7, 2014 at 1:32 AM, Marko Rauhamaa <marko@pacujo.net> wrote:
> Michael Torrie <torriem@gmail.com>:
>
>> On 06/06/2014 08:10 AM, Marko Rauhamaa wrote:
>>> Ethan Furman <ethan@stoneleaf.us>:
>>>> ASCII is *not* the state of "this string has no encoding" -- that
>>>> would be Unicode; a Unicode string, as a data type, has no encoding.
>>>
>>> Huh?
>>
>> [...]
>>
>> What part of his statement are you saying "Huh?" about?
>
> Unicode, like ASCII, is a code. Representing text in unicode is
> encoding.

Yes and no. "ASCII" means two things: Firstly, it's a mapping from the
letter A to the number 65, from the exclamation mark to 33, from the
backslash to 92, and so on. And secondly, it's an encoding of those
numbers into the lowest seven bits of a byte, with the high byte left
clear. Between those two, you get a means of representing the letter
'A' as the byte 0x41, and one of them is an encoding.

"Unicode", on the other hand, is only the first part. It maps all the
same characters to the same numbers that ASCII does, and then adds a
few more... a few followed by a few, followed by... okay, quite a lot
more. Unicode specifies that the character OK HAND SIGN, which looks
like 👌 if you have the right font, is number 1F44C in hex (128076
decimal). This is the "Universal Character Set" or UCS.

ASCII could specify a single encoding, because that encoding makes
sense for nearly all purposes. (There are times when you transmit
ASCII text and use the high bit to mean something else, like parity or
"this is the end of a word" or something, but even then, you follow
the same convention of packing a number into the low seven bits of a
byte.) Unicode can't, because there are many different pros and cons
to the different encodings, and so we have UCS Transformation Formats
like UTF-8 and UTF-32. Each one is an encoding that maps a codepoint
to a sequence of bytes.

You can't represent text in "Unicode" in a computer. Somewhere along
the way, you have to figure out how to store those codepoints as
bytes, or something more concrete (you could, for instance, use a
Python list of Python integers; I can't say that it would be in any
way more efficient than alternatives, but it would be plausible); and
that's the encoding.

ChrisA

Thread

Python 3.2 has some deadly infection Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-05-31 17:10 +0100
  Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-05-31 22:55 +0300
  Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-01 02:26 +0000
    Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-01 12:43 +1000
    Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 08:54 +1000
      Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-02 01:14 +0000
        Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 12:23 +1000
          Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-01 19:46 -0700
        Re: Python 3.2 has some deadly infection Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de> - 2014-06-02 07:45 +0000
        Re: Python 3.2 has some deadly infection Tim Delaney <timothy.c.delaney@gmail.com> - 2014-06-02 19:02 +1000
        Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-02 19:14 +1000
        Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-02 12:10 +0100
          Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-03 16:34 +0000
            Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-04 02:43 +1000
        Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-02 17:34 -0400
          Re: Python 3.2 has some deadly infection Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-06-03 17:16 +1200
            Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-03 02:21 -0400
            Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-03 15:18 +0100
              Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-04 13:08 +0000
                Re: Python 3.2 has some deadly infection Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-06-05 14:01 +1200
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 10:16 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-05 17:30 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 11:05 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-05 18:36 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 12:53 +0300
                Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-05 05:43 -0700
                Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 14:50 -0400
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 23:21 +0300
                Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 18:09 -0400
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 23:13 +0000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 02:30 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 09:39 +1000
                Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 22:08 -0400
                Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-05 20:47 -0700
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve@pearwood.info> - 2014-06-05 08:34 +0000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 12:41 +0300
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 06:37 -0700
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 17:45 +0300
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 15:33 +0000
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 02:12 +1000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 09:54 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:36 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 19:52 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:28 +1000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 15:35 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 08:52 +1000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 20:11 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 13:20 +1000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-05 20:32 -0700
                Re: Python 3.2 has some deadly infection Akira Li <4kir4.1i@gmail.com> - 2014-06-06 12:03 +0400
                Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-05 16:37 +0100
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 16:16 +0000
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 01:50 +1000
                Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-05 17:17 +0100
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 16:32 +0000
                Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-06 07:40 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-06 03:14 +1000
                Re: Python 3.2 has some deadly infection Ian Kelly <ian.g.kelly@gmail.com> - 2014-06-05 11:16 -0600
                Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-05 14:11 -0400
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-05 21:30 +0300
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-05 23:02 +0000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 02:21 +0300
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-06 12:15 +0000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 16:00 +0300
                Re: Python 3.2 has some deadly infection rurpy@yahoo.com - 2014-06-07 21:34 -0700
                Re: Python 3.2 has some deadly infection Ethan Furman <ethan@stoneleaf.us> - 2014-06-06 06:24 -0700
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 17:10 +0300
                Re: Python 3.2 has some deadly infection Michael Torrie <torriem@gmail.com> - 2014-06-06 09:02 -0600
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 18:32 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 01:50 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:02 +0300
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 10:13 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:26 +1000
                Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 11:03 -0700
                Re: Python 3.2 has some deadly infection Denis McMahon <denismfmcmahon@gmail.com> - 2014-06-06 21:18 +0000
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 08:18 +1000
                Re: Python 3.2 has some deadly infection Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-06-06 15:57 +0000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 09:21 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 02:48 +1000
                Re: Python 3.2 has some deadly infection Rustom Mody <rustompmody@gmail.com> - 2014-06-06 10:04 -0700
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:12 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:11 +0300
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 03:16 +1000
                Re: Python 3.2 has some deadly infection Marko Rauhamaa <marko@pacujo.net> - 2014-06-06 20:18 +0300
                Re: Python 3.2 has some deadly infection Ned Batchelder <ned@nedbatchelder.com> - 2014-06-06 13:33 -0400
                Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-07 01:25 +1000
                Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 08:44 -0700
                Re: Python 3.2 has some deadly infection wxjmfauth@gmail.com - 2014-06-06 08:48 -0700
                Re: Python 3.2 has some deadly infection Robin Becker <robin@reportlab.com> - 2014-06-06 12:56 +0100
                Re: Python 3.2 has some deadly infection Akira Li <4kir4.1i@gmail.com> - 2014-06-05 06:49 +0400
            Re: Python 3.2 has some deadly infection Chris Angelico <rosuav@gmail.com> - 2014-06-04 00:25 +1000
            Re: Python 3.2 has some deadly infection Terry Reedy <tjreedy@udel.edu> - 2014-06-03 14:22 -0400

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