Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #91812
| Newsgroups | comp.lang.python |
|---|---|
| Date | 2015-06-02 02:18 -0700 |
| References | (1 earlier) <7f287dcf-8d52-4ab8-9768-88d1f75da269@googlegroups.com> <bb48ac94-c2ac-4874-9c95-7ac2280fd5bc@googlegroups.com> <556d574f$0$12905$c3e8da3$5496439d@news.astraweb.com> <3d06de71-a517-4cac-be12-a61813465735@googlegroups.com> <mailman.48.1433234251.13271.python-list@python.org> |
| Message-ID | <08e0d883-95ce-4101-8330-3bc6832c8033@googlegroups.com> (permalink) |
| Subject | Re: Everything is an object in python - object class and type class |
| From | Rustom Mody <rustompmody@gmail.com> |
On Tuesday, June 2, 2015 at 2:08:08 PM UTC+5:30, Chris Angelico wrote:
> On Tue, Jun 2, 2015 at 5:44 PM, Rustom Mody wrote:
> >> Plates and spoons and knives and forks are objects.
> >> Cars and trucks and ships and planes are objects.
> >> Books and shoes and maps and compasses are objects.
> >> Buildings are objects.
> >> And blueprints of buildings are objects too.
> >
> > You are using 'are' as if they are all the same 'are'. Are they?
> > Consider the type int.
> > It is supposed to model mathematical integers.
> > ie 1 ∈ int (in some sense)
> >
> > Consider the generator
> > def int2():
> > i = 0
> > yield i
> > while True:
> > yield i
> > yield -i
> >
> > 1 ∈ int2 [Not to mention 1 ∈ int2()]
> >
> > Consider range(10) (in python2 and 3)
> > And finally [1,2,3,4]
> >
> > 1 ∈ all these
> > Are the '∈'s here same? Similar?
>
> Yes, they are. Every one of them is asserting (or asking, depending on
> your point of view) whether or not the instance to its left is a
> member of the set to its right. The sets on the right are all
> different, but the set membership operation is identical.
>
> But even more so: The original collection of statements ("are
> objects") all used the same RHS. In exactly the same senses, all of
> those examples were testing for the same "objectness". (Although you
> could argue that Steven's examples were talking about subclass
> relationships rather than instance relationships, but really, an
> instanceof relationship is a special case of subclass, where the class
> on the left is defined by some form of object identity. Stating "All
> books are objects" is a subclass relationship; stating "This book is
> an object" is an instanceof relationship; both assertions use the same
> meaning of "object(s)".)
>
> All shoes are objects.
> All ships are objects.
> All lumps of sealing-wax are objects.
> All cabbages are objects.
> All kings are objects. (Some kings are also subjects, but not many.)
>
> I can pick up a shoe, I can look at it, I can verify that it has
> certain attributes common to all objects (location, mass, etc).
> Superman can do the same with a ship (they're a bit big for me to pick
> up). The actions you can perform on all objects are the attributes of
> objects in general. Some subclasses of object may provide additional
> actions (you can tip a king, for instance), but you can still do all
> of these actions, so they're all the same type of object.
>
> Note that not one iota of this has anything to do with Python's
> documentation, its rules, its behaviour, or anything. Python follows
> the natural expectations of our universe. The standard actions that
> can be performed on Python objects are slightly different from the
> standard actions that can be performed in Dungeons and Dragons, and
> different again from the standard actions of the world we live in, but
> they are no less applicable to all objects in that hierarchy:
>
> * You can bind a name to an object (any object).
> * You can pass an object as a function parameter.
> * You can return an object from a function.
> * You can reference objects in other objects' attributes.
> * You can distinguish one object from another (that is, objects have
> unique identities).
>
> (In CPython, you can recognize an object by its GC header - an object
> invariably has a reference count and so on. This is not a fundamental
> attribute of objects, but it's a way to recognize them.)
>
> Not everything that Python uses is an object. Syntax is not, itself,
> manipulable; you can represent a syntax tree with either source code
> (as a string) or an AST object, but syntax itself is not something you
> can grasp. You can't assign "foo = def" in Python. But anything that
> you can work with, in any way, is an object - and is an instance of
> (some subclass of) the type 'object'. So, yes: They ARE all the same
> meaning of "are" and "objects".
Lets take this practically.
>>> isinstance(1,int)
True
>>> 1 in [1,2,3]
True
>>> def int2():
... i = 0
... while True:
... yield i
... i += 1
>>> 1 in int2()
True
>>>
>>> 1 in range(10)
True
4 True-returning python expressions. 5 if you consider that range in python 2
and 3 are quite different.
Do you consider the computational processes evoked (in the CPython sources) by
these 4 statements to be the same?
[Hint: What does
>>> "shoes" in int2()
return?
And try to take care to distinguish computational from ontological answer
]
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 07:34 -0700
Re: Everything is an object in python - object class and type class Marco Buttu <marco.buttu@gmail.com> - 2015-05-31 17:13 +0200
Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-05-31 11:37 -0400
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 04:00 +1000
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-01 10:35 -0700
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 17:29 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 14:09 +1000
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-05-31 20:09 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-01 14:24 +1000
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-01 05:03 -0700
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-01 23:59 +0100
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 11:45 +0100
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 04:16 -0700
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 09:09 -0600
Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 17:24 -0700
Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 10:32 +1000
Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 18:02 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:30 +1000
Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 18:15 -0700
Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 11:30 +1000
Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 00:13 -0400
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:23 +1000
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-01 20:15 -0700
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 04:46 +0100
Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 21:47 -0700
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-01 22:01 -0700
Religion [was Re: Everything is an object in python - object class and type class] Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 16:04 +1000
Re: Religion [was Re: Everything is an object in python - object class and type class] Rustom Mody <rustompmody@gmail.com> - 2015-06-01 23:17 -0700
Re: Religion [was Re: Everything is an object in python - object class and type class] Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 07:20 +0100
Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 00:08 -0400
Re: Everything is an object in python - object class and type class TheDoctor <dreamingforward@gmail.com> - 2015-06-01 21:54 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-02 17:12 +1000
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 00:44 -0700
Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-02 18:37 +1000
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 02:18 -0700
Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-02 12:23 +0300
Re: Everything is an object in python - object class and type class vern.muhr@gmail.com - 2015-06-01 14:12 -0700
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-02 03:36 -0700
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 12:11 +0100
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-02 21:27 +1000
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 04:40 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-03 01:08 +1000
Re: Everything is an object in python - object class and type class Rustom Mody <rustompmody@gmail.com> - 2015-06-02 09:14 -0700
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 13:49 +0100
Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-02 16:13 +0300
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-03 03:00 +1000
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-02 18:59 +0100
Re: Everything is an object in python - object class and type class random832@fastmail.us - 2015-06-02 14:07 -0400
Re: Everything is an object in python - object class and type class Ned Batchelder <ned@nedbatchelder.com> - 2015-06-02 11:10 -0700
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:36 -0600
Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 18:10 +0000
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 11:22 -0700
Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 18:47 +0000
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 12:00 -0700
Re: Everything is an object in python - object class and type class Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2015-06-02 19:31 +0000
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:50 -0600
Re: Everything is an object in python - object class and type class Grant Edwards <invalid@invalid.invalid> - 2015-06-02 21:19 +0000
Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 01:33 +0300
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 15:49 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:13 +1000
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:38 -0700
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:24 +1000
Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 11:57 +0300
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-03 07:57 -0600
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:42 -0700
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 12:58 -0700
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-02 22:47 +0100
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 18:49 -0600
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:32 +1000
Re: Everything is an object in python - object class and type class Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-02 13:37 -0600
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-03 18:08 +1000
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-02 11:00 -0700
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-02 21:16 -0700
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 06:23 +0100
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 11:20 +0100
Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-03 20:38 +1000
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 12:08 +0100
Re: Everything is an object in python - object class and type class Marko Rauhamaa <marko@pacujo.net> - 2015-06-03 15:08 +0300
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 17:00 +0100
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 17:29 +0100
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 19:59 +0100
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 21:58 +0100
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 22:33 +0100
Re: Everything is an object in python - object class and type class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 22:49 +0100
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-04 00:04 +0100
Re: Everything is an object in python - object class and type class Laura Creighton <lac@openend.se> - 2015-06-04 12:06 +0200
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-04 13:01 +0100
Re: Everything is an object in python - object class and type class Laura Creighton <lac@openend.se> - 2015-06-04 15:39 +0200
Re: Everything is an object in python - object class and type class "Dr. Bigcock" <dreamingforward@gmail.com> - 2015-06-03 21:50 -0700
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-03 22:43 -0700
Re: Everything is an object in python - object class and type class Michael Torrie <torriem@gmail.com> - 2015-06-03 10:36 -0600
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 18:26 +0100
Re: Everything is an object in python - object class and type class Steven D'Aprano <steve@pearwood.info> - 2015-06-05 00:11 +1000
Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-03 13:17 -0400
Re: Everything is an object in python - object class and type class Chris Angelico <rosuav@gmail.com> - 2015-06-03 22:19 +1000
Re: Everything is an object in python - object class and type class Marco Buttu <marco.buttu@gmail.com> - 2015-06-03 14:10 +0200
Re: Everything is an object in python - object class and type class BartC <bc@freeuk.com> - 2015-06-03 12:13 +0100
Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-03 13:05 -0400
Re: Everything is an object in python - object class and type class Terry Reedy <tjreedy@udel.edu> - 2015-06-02 12:23 -0400
Re: Everything is an object in python - object class and type class Eddilbert Macharia <edd.cowan@gmail.com> - 2015-06-03 06:17 -0700
csiph-web