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Groups > comp.lang.python > #22304
| Date | 2012-03-28 14:20 -0500 |
|---|---|
| From | Evan Driscoll <driscoll@cs.wisc.edu> |
| Subject | Re: Re: "convert" string to bytes without changing data (encoding) |
| References | <9tg21lFmo3U1@mid.dfncis.de> <mailman.1065.1332925364.3037.python-list@python.org> <jkvb5a$88d$1@rumours.uwaterloo.ca> <4f73504c$0$29981$c3e8da3$5496439d@news.astraweb.com> <jkvktq$u16$1@rumours.uwaterloo.ca> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.1092.1332962455.3037.python-list@python.org> (permalink) |
On 01/-10/-28163 01:59 PM, Ross Ridge wrote:
> Steven D'Aprano<steve+comp.lang.python@pearwood.info> wrote:
>> The right way to convert bytes to strings, and vice versa, is via
>> encoding and decoding operations.
>
> If you want to dictate to the original poster the correct way to do
> things then you don't need to do anything more that. You don't need to
> pretend like Chris Angelico that there's isn't a direct mapping from
> the his Python 3 implementation's internal respresentation of strings
> to bytes in order to label what he's asking for as being "silly".
That mapping may as well be:
def get_bytes(some_string):
import random
length = random.randint(len(some_string), 5*len(some_string))
bytes = [0] * length
for i in xrange(length):
bytes[i] = random.randint(0, 255)
return bytes
Of course this is hyperbole, but it's essentially about as much
guarantee as to what the result is.
As many others have said, the encoding isn't defined, and I would guess
varies between implementations. (E.g. if Jython and IronPython use their
host platforms' native strings, both have 16-bit chars and thus probably
use UTF-16 encoding. I am not sure what CPython uses, but I bet it's
*not* that.)
It's even guaranteed that the byte representation won't change! If
something is lazily evaluated or you have a COW string or something, the
bytes backing it will differ.
So yes, you can say that pretending there's not a mapping of strings to
internal representation is silly, because there is. However, there's
nothing you can say about that mapping.
Evan
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"convert" string to bytes without changing data (encoding) Peter Daum <gator@cs.tu-berlin.de> - 2012-03-28 10:56 +0200
Re: "convert" string to bytes without changing data (encoding) Chris Angelico <rosuav@gmail.com> - 2012-03-28 20:02 +1100
Re: "convert" string to bytes without changing data (encoding) Peter Daum <gator@cs.tu-berlin.de> - 2012-03-28 11:43 +0200
Re: "convert" string to bytes without changing data (encoding) Heiko Wundram <modelnine@modelnine.org> - 2012-03-28 12:42 +0200
Re: "convert" string to bytes without changing data (encoding) Peter Daum <gator@cs.tu-berlin.de> - 2012-03-28 19:43 +0200
Re: "convert" string to bytes without changing data (encoding) Heiko Wundram <modelnine@modelnine.org> - 2012-03-28 20:13 +0200
Re: "convert" string to bytes without changing data (encoding) Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2012-03-28 21:13 +0300
RE: "convert" string to bytes without changing data (encoding) "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-03-28 18:31 +0000
Re: "convert" string to bytes without changing data (encoding) Ethan Furman <ethan@stoneleaf.us> - 2012-03-28 11:49 -0700
RE: "convert" string to bytes without changing data (encoding) "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-03-28 18:20 +0000
Re: "convert" string to bytes without changing data (encoding) Ian Kelly <ian.g.kelly@gmail.com> - 2012-03-28 12:20 -0600
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-28 18:26 +0000
Re: "convert" string to bytes without changing data (encoding) Grant Edwards <invalid@invalid.invalid> - 2012-03-28 19:40 +0000
Re: "convert" string to bytes without changing data (encoding) Ethan Furman <ethan@stoneleaf.us> - 2012-03-28 11:17 -0700
Re: "convert" string to bytes without changing data (encoding) John Nagle <nagle@animats.com> - 2012-03-28 12:30 -0700
Re: "convert" string to bytes without changing data (encoding) Terry Reedy <tjreedy@udel.edu> - 2012-03-28 17:37 -0400
Re: "convert" string to bytes without changing data (encoding) Peter Daum <gator@cs.tu-berlin.de> - 2012-03-29 16:57 +0200
Re: "convert" string to bytes without changing data (encoding) Peter Daum <gator@cs.tu-berlin.de> - 2012-03-29 16:57 +0200
Re: "convert" string to bytes without changing data (encoding) Serhiy Storchaka <storchaka@gmail.com> - 2012-03-30 22:06 +0300
Re: "convert" string to bytes without changing data (encoding) Chris Angelico <rosuav@gmail.com> - 2012-03-31 06:10 +1100
Re: "convert" string to bytes without changing data (encoding) Stefan Behnel <stefan_ml@behnel.de> - 2012-03-28 13:25 +0200
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-28 18:12 +0000
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 11:36 -0400
Re: "convert" string to bytes without changing data (encoding) Chris Angelico <rosuav@gmail.com> - 2012-03-29 03:18 +1100
Re: "convert" string to bytes without changing data (encoding) Grant Edwards <invalid@invalid.invalid> - 2012-03-28 16:33 +0000
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 14:05 -0400
Re: "convert" string to bytes without changing data (encoding) Tim Chase <python.list@tim.thechases.com> - 2012-03-28 13:49 -0500
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 15:10 -0400
Re: "convert" string to bytes without changing data (encoding) "Albert W. Hopkins" <marduk@letterboxes.org> - 2012-03-28 15:22 -0400
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-28 17:54 +0000
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 14:22 -0400
Re: Re: "convert" string to bytes without changing data (encoding) Evan Driscoll <driscoll@cs.wisc.edu> - 2012-03-28 14:20 -0500
Re: Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 15:43 -0400
Re: "convert" string to bytes without changing data (encoding) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-03-28 21:44 +0100
Re: "convert" string to bytes without changing data (encoding) Neil Cerutti <neilc@norwich.edu> - 2012-03-28 20:56 +0000
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-29 00:02 +0000
Re: Re: Re: "convert" string to bytes without changing data (encoding) Evan Driscoll <driscoll@cs.wisc.edu> - 2012-03-28 19:11 -0500
Re: Re: Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 23:04 -0400
Re: Re: Re: "convert" string to bytes without changing data (encoding) Chris Angelico <rosuav@gmail.com> - 2012-03-29 14:31 +1100
Re: Re: Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-28 23:58 -0400
Re: "convert" string to bytes without changing data (encoding) Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-03-29 07:01 +0100
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-29 06:51 +0000
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-29 11:30 -0400
Re: "convert" string to bytes without changing data (encoding) Terry Reedy <tjreedy@udel.edu> - 2012-03-29 12:49 -0400
Re: "convert" string to bytes without changing data (encoding) Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-03-29 14:00 -0400
Re: "convert" string to bytes without changing data (encoding) Chris Angelico <rosuav@gmail.com> - 2012-03-30 07:41 +1100
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-30 01:16 +0000
Re: Re: Re: Re: "convert" string to bytes without changing data (encoding) Evan Driscoll <driscoll@cs.wisc.edu> - 2012-03-29 11:31 -0500
RE: "convert" string to bytes without changing data (encoding) "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-03-28 19:02 +0000
Re: "convert" string to bytes without changing data (encoding) Grant Edwards <invalid@invalid.invalid> - 2012-03-28 19:44 +0000
Re: "convert" string to bytes without changing data (encoding) MRAB <python@mrabarnett.plus.com> - 2012-03-28 20:50 +0100
RE: "convert" string to bytes without changing data (encoding) "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-03-29 17:36 +0000
Re: "convert" string to bytes without changing data (encoding) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-30 01:10 +0000
Re: "convert" string to bytes without changing data (encoding) Michael Ströder <michael@stroeder.com> - 2012-03-30 09:04 +0200
Re: "convert" string to bytes without changing data (encoding) Terry Reedy <tjreedy@udel.edu> - 2012-03-28 14:11 -0400
Re: "convert" string to bytes without changing data (encoding) Stefan Behnel <stefan_ml@behnel.de> - 2012-03-28 11:08 +0200
Re: "convert" string to bytes without changing data (encoding) Dave Angel <d@davea.name> - 2012-03-28 13:16 -0400
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