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Groups > comp.lang.python > #84681

Re: An object is an instance (or not)?

From Ben Finney <ben+python@benfinney.id.au>
Subject Re: An object is an instance (or not)?
Date 2015-01-28 09:32 +1100
References (2 earlier) <MPG.2f321c24a502d2bb9896a3@nntp.aioe.org> <a771f6f2-9aa3-44ca-9f87-88a984c7c27e@googlegroups.com> <MPG.2f3224d1997790e19896a7@nntp.aioe.org> <9a2cf6ca-2eb8-4a87-9e83-e87d90d5fe42@googlegroups.com> <MPG.2f322851e6cf90ad9896a8@nntp.aioe.org>
Newsgroups comp.lang.python
Message-ID <mailman.18189.1422397927.18130.python-list@python.org> (permalink)

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Mario Figueiredo <marfig@gmail.com> writes:

> People were saying to me that in Python object = instance. I'm trying
> to argue why I believe it isn't and asking for arguments to convince
> me otherwise.

In Python:

* Every value is an object.

* Every object is an instance of some class.

* To say “object” is uproblematic for values in Python, because the
  programming term “object” doesn't imply anything about classes.

* To say “instance” implies a specific relationship to some particular
  class; in programming terminology (because in English generally) an
  instance is so called only because it is an instance of some specific
  class.

> By referring to an instance of Sub as "Sub object", there's an
> implicit affirmation that an object is an instance.

Correct. That raises a fourth point:

* In the distant past of Python, some objects were not instances of any
  class; the terminology in the documentation and messages shows some
  confusing legacies from that ancient time.

The phrasing “'Foo' object” is ambiguous in a way that “'Foo' instance”
would not be. I agree with others that changing the message to refer to
“'Foo' instance” would be an improvement.

-- 
 \         “Pinky, are you pondering what I'm pondering?” “I think so, |
  `\    Brain, but I find scratching just makes it worse.” —_Pinky and |
_o__)                                                       The Brain_ |
Ben Finney

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Thread

An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-27 21:12 +0100
  Re: An object is an instance (or not)? Ethan Furman <ethan@stoneleaf.us> - 2015-01-27 12:36 -0800
  Re: An object is an instance (or not)? André Roberge <andre.roberge@gmail.com> - 2015-01-27 12:50 -0800
    Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-27 22:06 +0100
      Re: An object is an instance (or not)? André Roberge <andre.roberge@gmail.com> - 2015-01-27 13:38 -0800
        Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-27 22:43 +0100
          Re: An object is an instance (or not)? André Roberge <andre.roberge@gmail.com> - 2015-01-27 13:49 -0800
            Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-27 22:58 +0100
              Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 09:32 +1100
                Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 18:55 +1100
                Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 22:20 +1100
              Re: An object is an instance (or not)? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-01-27 23:12 +0000
                Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 01:52 +0100
                Re: An object is an instance (or not)? Marko Rauhamaa <marko@pacujo.net> - 2015-01-28 07:25 +0200
                Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-27 21:53 -0800
                Re: An object is an instance (or not)? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-01-28 05:57 +0000
                Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 11:48 +0100
      Re: An object is an instance (or not)? random832@fastmail.us - 2015-01-28 00:37 -0500
        Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 19:45 +1100
      Re: An object is an instance (or not)? Devin Jeanpierre <jeanpierreda@gmail.com> - 2015-01-27 21:43 -0800
      Re: An object is an instance (or not)? random832@fastmail.us - 2015-01-28 01:01 -0500
        Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-27 22:22 -0800
          Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 18:03 +1100
        Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 19:48 +1100
      Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 17:59 +1100
      Re: An object is an instance (or not)? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-28 20:21 +1300
      Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 18:48 +1100
      Re: An object is an instance (or not)? random832@fastmail.us - 2015-01-28 12:08 -0500
        Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-28 18:29 -0800
  Re: An object is an instance (or not)? Ned Batchelder <ned@nedbatchelder.com> - 2015-01-27 18:22 -0500
    Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 01:17 +0100
      Re: An object is an instance (or not)? Chris Angelico <rosuav@gmail.com> - 2015-01-28 11:30 +1100
        Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 01:35 +0100
          Re: An object is an instance (or not)? alex23 <wuwei23@gmail.com> - 2015-01-28 14:44 +1000
          Re: An object is an instance (or not)? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-28 23:33 +1300
            Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 22:52 +1100
              Re: An object is an instance (or not)? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-29 19:22 +1300
                Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-29 18:16 +1100
                Re: An object is an instance (or not)? Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-29 08:48 -0700
                Re: An object is an instance (or not)? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-30 22:07 +1300
                Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-31 10:45 +1100
      Re: An object is an instance (or not)? Ned Batchelder <ned@nedbatchelder.com> - 2015-01-27 21:21 -0500
        Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-27 18:52 -0800
        Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 20:16 +1100
          Re: An object is an instance (or not)? Chris Angelico <rosuav@gmail.com> - 2015-01-28 21:01 +1100
            Re: An object is an instance (or not)? Rick Johnson <rantingrickjohnson@gmail.com> - 2015-01-29 14:22 -0800
      Re: An object is an instance (or not)? Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-27 19:15 -0700
      Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 20:28 +1100
      Re: An object is an instance (or not)? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-01-28 23:33 +1300
    Re: An object is an instance (or not)? Grant Edwards <invalid@invalid.invalid> - 2015-01-28 00:23 +0000
  Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 10:39 +1100
    Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 01:24 +0100
      Re: An object is an instance (or not)? Ben Finney <ben+python@benfinney.id.au> - 2015-01-28 12:00 +1100
        Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 02:14 +0100
      Re: An object is an instance (or not)? alex23 <wuwei23@gmail.com> - 2015-01-28 14:47 +1000
        Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-27 21:23 -0800
        Re: An object is an instance (or not)? random832@fastmail.us - 2015-01-28 00:44 -0500
          Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 20:21 +1100
      Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 20:17 +1100
    Re: An object is an instance (or not)? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-28 20:09 +1100
  Re: An object is an instance (or not)? Chris Angelico <rosuav@gmail.com> - 2015-01-28 10:42 +1100
    Re: An object is an instance (or not)? Mario Figueiredo <marfig@gmail.com> - 2015-01-28 01:31 +0100
  Re: An object is an instance (or not)? Rustom Mody <rustompmody@gmail.com> - 2015-01-27 18:11 -0800

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