Re: Values and objects [was Re: Pass variable by reference]

From	Mark H Harris <harrismh777@gmail.com>
Newsgroups	comp.lang.python
Subject	Re: Values and objects [was Re: Pass variable by reference]
Date	2014-05-09 16:56 -0500
Organization	Aioe.org NNTP Server
Message-ID	<lkjitj$d0c$1@speranza.aioe.org> (permalink)
References	(3 earlier) <lkbigv$ban$1@speranza.aioe.org> <mailman.9713.1399419985.18130.python-list@python.org> <lkdt0u$moc$1@speranza.aioe.org> <87ppjpwafk.fsf@elektro.pacujo.net> <536ad8f2$0$29965$c3e8da3$5496439d@news.astraweb.com>

Show all headers | View raw

On 5/7/14 8:08 PM, Steven D'Aprano wrote:
> In Python, all values *are* objects. It isn't a matter of choosing one or
> the other. The value 1 is an object, not a native (low-level, unboxed) 32
> or 64 bit int.
>
> Unlike C# or Java, there is no direct language facility to box native
> values into objects or unbox objects to native values.
>
     Yes.  In the context of the rest of this discussion, this one point 
is just one of the many reasons why it is not helpful to think of 
Python's {name: object} relationship as 'variable -- value'.

     Typically when I think about variables (particularly from the past, 
say Pascal, Basic, C, Fortran, Cobol &c) I am thinking about modeling 
memory is some way where the variable (some naming convention) is a 
value handle or value pointer of some chunk of memory (by type | length) 
---  where I am creating a 'box' into which I may place something 
(usually some native type).

     When I think of Python's 'variables' (and I don't believe Python 
has variables) I am now thinking of a naming convention (for handling 
objects) where I am not the least interested in modeling memory for 
native types. I am instead interested in modeling the real world (or 
subset) with object abstractions. I am no longer interested in creating 
a 'box' into which I may place some type. I don't need variables any 
longer for that purpose.  What I want is some very efficient naming 
convention whereby I can handle the objects I am constructing (for 
whatever abstract purpose).

     If a programmer new to Python thinks in terms of 'variables' from C 
or Pascal, or Fortran or Basic, they will run into surprises when it 
comes to handling the {name: object} idea in Python. In fact, most of 
the time this debate comes up it is precisely that the new user is 
finding Python's 'variables' aren't behaving correctly or finding that 
they are not able to 'do' what they used to do (say) with C's variables.

     It really comes down to the definition of 'variable' and whether 
the language in question is modeling memory, or modeling object 
abstractions.

marcus

Thread

Re: Pass variable by reference Ned Batchelder <ned@nedbatchelder.com> - 2014-05-06 16:31 -0400
  Re: Pass variable by reference Mark H Harris <harrismh777@gmail.com> - 2014-05-06 16:00 -0500
    Re: Pass variable by reference Ned Batchelder <ned@nedbatchelder.com> - 2014-05-06 17:27 -0400
    Re: Pass variable by reference Chris Angelico <rosuav@gmail.com> - 2014-05-07 09:46 +1000
      Re: Pass variable by reference Rustom Mody <rustompmody@gmail.com> - 2014-05-06 19:18 -0700
        Re: Pass variable by reference Chris Angelico <rosuav@gmail.com> - 2014-05-07 12:39 +1000
          Re: Pass variable by reference Rustom Mody <rustompmody@gmail.com> - 2014-05-06 19:54 -0700
            Re: Pass variable by reference Steven D'Aprano <steve@pearwood.info> - 2014-05-07 04:59 +0000
      Re: Pass variable by reference Mark H Harris <harrismh777@gmail.com> - 2014-05-07 13:11 -0500
        Re: Pass variable by reference Marko Rauhamaa <marko@pacujo.net> - 2014-05-08 00:22 +0300
          Values and objects [was Re: Pass variable by reference] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-08 01:08 +0000
            Re: Values and objects [was Re: Pass variable by reference] Mark H Harris <harrismh777@gmail.com> - 2014-05-09 16:56 -0500
              Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-10 01:34 +0300
                Re: Values and objects Ben Finney <ben@benfinney.id.au> - 2014-05-10 10:24 +1000
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 01:01 +0000
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-09 19:19 -0700
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-10 12:33 +1000
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-09 20:05 -0700
                Re: Values and objects Mark H Harris <harrismh777@gmail.com> - 2014-05-09 23:15 -0500
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 06:15 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-10 17:21 +1000
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 09:09 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-10 19:32 +1000
                Re: Values and objects Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 12:10 -0700
                Re: Values and objects MRAB <python@mrabarnett.plus.com> - 2014-05-10 20:22 +0100
                Re: Values and objects Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 12:28 -0700
                Re: Values and objects Terry Reedy <tjreedy@udel.edu> - 2014-05-10 16:16 -0400
                Re: Values and objects Terry Reedy <tjreedy@udel.edu> - 2014-05-10 16:24 -0400
                Re: Values and objects Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-05-10 14:03 -0700
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 03:17 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-11 13:30 +1000
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 05:11 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-11 15:22 +1000
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-10 22:31 -0700
                Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-11 09:21 +0300
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-10 23:48 -0700
                Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-11 18:10 +0300
                Re: Values and objects Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2014-05-11 11:26 +0300
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-11 01:48 -0700
                Re: Values and objects Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2014-05-11 15:22 +0300
                Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-11 18:46 +0300
                Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-11 22:56 +0300
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 12:51 +0000
                Re: Values and objects Rustom Mody <rustompmody@gmail.com> - 2014-05-11 07:12 -0700
                Re: Values and objects Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 22:42 -0700
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 06:40 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-11 09:18 +1000
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 03:11 +0000
                Re: Values and objects Rotwang <sg552@hotmail.co.uk> - 2014-05-11 14:46 +0100
                Re: Values and objects Ned Batchelder <ned@nedbatchelder.com> - 2014-05-11 14:40 -0400
                Re: Values and objects Rotwang <sg552@hotmail.co.uk> - 2014-05-12 00:06 +0100
                Re: Values and objects Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 18:28 -0700
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 07:24 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-11 11:59 +1000
                Re: Values and objects Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-11 07:29 +0000
                Re: Values and objects Ethan Furman <ethan@stoneleaf.us> - 2014-05-10 21:46 -0700
                Re: [Python-Dev] Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-11 16:08 +1000
                Re: Values and objects albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-05-17 14:26 +0000
                Re: Values and objects Chris Angelico <rosuav@gmail.com> - 2014-05-10 11:58 +1000
                Re: Values and objects Marko Rauhamaa <marko@pacujo.net> - 2014-05-10 10:57 +0300
                Re: Values and objects Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2014-05-10 11:06 +0300
                Re: Values and objects Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-05-10 12:07 -0400
        Re: Pass variable by reference Chris Angelico <rosuav@gmail.com> - 2014-05-08 11:31 +1000
          Re: Pass variable by reference Mark H Harris <harrismh777@gmail.com> - 2014-05-09 17:30 -0500
            Abstractions [was Re: Pass variable by reference] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-10 00:58 +0000
              Re: Abstractions [was Re: Pass variable by reference] Mark H Harris <harrismh777@gmail.com> - 2014-05-09 21:17 -0500
  Re: Pass variable by reference Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-07 01:14 +0000

csiph-web