Re: Encapsulation unpythonic?

Newsgroups	comp.lang.python
Date	2013-08-31 01:00 -0700
References	(1 earlier) <8c7c4854-70e1-46e7-a3ff-a3206c4c5c27@googlegroups.com> <5221567b$0$6599$c3e8da3$5496439d@news.astraweb.com> <ecd32f98-6ba8-4b1e-91d3-e0fd6a8034c3@googlegroups.com> <mailman.402.1377932649.19984.python-list@python.org> <95e00c44-9e65-47d6-823e-6211fa4d597d@googlegroups.com>
Message-ID	<ca3978ef-7564-419d-9639-6d21e78bb36d@googlegroups.com> (permalink)
Subject	Re: Encapsulation unpythonic?
From	Fabrice Pombet <fp2161@gmail.com>

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On Saturday, August 31, 2013 9:42:55 AM UTC+2, Fabrice Pombet wrote:
> On Saturday, August 31, 2013 9:03:58 AM UTC+2, Gary Herron wrote:
> 
> > On 08/30/2013 11:07 PM, Fabrice Pombet
> 
> >       wrote:
> 
> > 
> 
> >     
> 
> >     ... long discussion elided ...
> 
> > 
> 
> >       well, look at that:
> 
> > 
> 
> > a=(1,2)
> 
> > a=2+3 ->a is an object and I have changed its type and value from outside. As far as I am concerned this is one hell of an encapsulation violation... Could you do this -strictly speaking- in Java or C++?
> 
> > 
> 
> >     
> 
> >     
> 
> > 
> 
> >     Yes, in fact you can do that in C++ and java:
> 
> > 
> 
> >     
> 
> > 
> 
> >     Obj1 a = ...some object...;
> 
> > 
> 
> >     { // new scope...
> 
> > 
> 
> >        Obj2 a = ...another object...;
> 
> > 
> 
> >     }
> 
> > 
> 
> >     
> 
> > 
> 
> >     On one line, the name 'a' is bound to one object, and later it is
> 
> >     bound to another object.   Your Python code is similar, binding the
> 
> >     name 'a' to object (1,2) on one line and the object 5 on the next
> 
> >     line.  Granted, Python seems a little freer because, with it's
> 
> >     dynamic typing,  one doesn't need to create a new scope to rebind a
> 
> >     name, but all languages with variable names allow some control over
> 
> >     binding/rebinding names.
> 
> > 
> 
> >     
> 
> > 
> 
> >     But this has *nothing* at all to do with objects and encapsulation.
> 
> > 
> 
> >     
> 
> > 
> 
> >     Please don't confuse:
> 
> > 
> 
> >     the binding of names to objects and
> 
> > 
> 
> >       
> 
> > 
> 
> >       the existence of objects and their encapsulated behavior
> 
> > 
> 
> >     
> 
> >     They are very different things.
> 
> > 
> 
> >     
> 
> > 
> 
> >     -- 
> 
> > Dr. Gary Herron
> 
> > Department of Computer Science
> 
> > DigiPen Institute of Technology
> 
> > (425) 895-4418
> 
> 
> 
> That's interesting, can you do this in C++ or java:
> 
> 
> 
> class X():
    def __init__(self, *arg):
        for x in arg:
            self.x=x

and then:

a=X("x","y","z")
and then:
a.w="w" 
?

I guess my point was dynamic typing and encapsulation go a little in opposite directions in terms of philosophy, and it is therefore clear that Python privileges "dynamic typing" kind of thinking over encapsulation as a philosophical stance. Am I the only one thinking like this?

Thread

Encapsulation unpythonic? fsaldan1@gmail.com - 2013-08-17 05:26 -0700
  Re: Encapsulation unpythonic? Skip Montanaro <skip@pobox.com> - 2013-08-17 07:54 -0500
  Re: Encapsulation unpythonic? David <bouncingcats@gmail.com> - 2013-08-17 23:05 +1000
  Re: Encapsulation unpythonic? Chris Angelico <rosuav@gmail.com> - 2013-08-17 16:50 +0100
  Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-17 16:17 +0000
    Re: Encapsulation unpythonic? Joshua Landau <joshua@landau.ws> - 2013-08-18 18:15 +0100
      Re: Encapsulation unpythonic? Steven D'Aprano <steve@pearwood.info> - 2013-08-19 07:05 +0000
        Re: Encapsulation unpythonic? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-08-19 18:57 -0400
        Re: Encapsulation unpythonic? random832@fastmail.us - 2013-08-21 12:52 -0400
          Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-22 02:06 +0000
        Re: Encapsulation unpythonic? Ian Kelly <ian.g.kelly@gmail.com> - 2013-08-21 16:02 -0600
  Re: Encapsulation unpythonic? Gary Herron <gary.herron@islandtraining.com> - 2013-08-17 13:16 -0700
  Re: Encapsulation unpythonic? Terry Reedy <tjreedy@udel.edu> - 2013-08-17 17:22 -0400
  Re: Encapsulation unpythonic? Chris Angelico <rosuav@gmail.com> - 2013-08-18 01:59 +0100
  Re: Encapsulation unpythonic? chaz2cry@gmail.com - 2013-08-22 19:12 -0700
  Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 10:43 -0700
    Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-31 02:35 +0000
      Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 23:07 -0700
        Re: Encapsulation unpythonic? Marco Buttu <marco.buttu@gmail.com> - 2013-08-31 08:49 +0200
        Re: Encapsulation unpythonic? Gary Herron <gherron@digipen.edu> - 2013-08-31 00:03 -0700
          Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-31 00:42 -0700
            Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-31 01:00 -0700
        Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-31 11:46 +0000
          Re: Encapsulation unpythonic? Ned Batchelder <ned@nedbatchelder.com> - 2013-08-31 08:41 -0400
            Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-31 05:49 -0700
          Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-08-31 05:57 -0700
            Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-01 08:10 +0000
              Re: Encapsulation unpythonic? Chris Angelico <rosuav@gmail.com> - 2013-09-01 18:21 +1000
                Re: Encapsulation unpythonic? Fabrice Pombet <fp2161@gmail.com> - 2013-09-01 03:09 -0700
                Re: Encapsulation unpythonic? Ethan Furman <ethan@stoneleaf.us> - 2013-09-01 11:42 -0700
                Re: Encapsulation unpythonic? Roy Smith <roy@panix.com> - 2013-09-01 15:13 -0400
                Re: Encapsulation unpythonic? Ethan Furman <ethan@stoneleaf.us> - 2013-09-01 13:33 -0700
                Re: Encapsulation unpythonic? Tim Delaney <timothy.c.delaney@gmail.com> - 2013-09-02 07:54 +1000
                Re: Encapsulation unpythonic? Roy Smith <roy@panix.com> - 2013-09-01 18:02 -0400
                Re: Encapsulation unpythonic? Ethan Furman <ethan@stoneleaf.us> - 2013-09-01 17:24 -0700
                Re: Encapsulation unpythonic? Roy Smith <roy@panix.com> - 2013-09-01 20:59 -0400
                Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-02 02:57 +0000
                Re: Encapsulation unpythonic? Ethan Furman <ethan@stoneleaf.us> - 2013-09-01 21:15 -0700
                Re: Encapsulation unpythonic? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-02 01:57 +0000
              Re: Encapsulation unpythonic? Ben Finney <ben+python@benfinney.id.au> - 2013-09-02 09:32 +1000
                Re: Encapsulation unpythonic? Roy Smith <roy@panix.com> - 2013-09-01 20:52 -0400
          Re: Encapsulation unpythonic? "Rhodri James" <rhodri@wildebst.demon.co.uk> - 2013-09-03 00:29 +0100
            Re: Encapsulation unpythonic? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-09-03 22:41 -0400
        Re: Encapsulation unpythonic? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-08-31 13:31 -0400
        Re: Encapsulation unpythonic? Tim Delaney <timothy.c.delaney@gmail.com> - 2013-09-01 03:47 +1000
    Re: Encapsulation unpythonic? 88888 Dihedral <dihedral88888@gmail.com> - 2013-09-02 14:43 -0700

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