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Groups > comp.lang.python > #92108
| From | Dennis Lee Bieber <wlfraed@ix.netcom.com> |
|---|---|
| Subject | Re: Can Python function return multiple data? |
| Date | 2015-06-04 19:51 -0400 |
| Organization | IISS Elusive Unicorn |
| References | (5 earlier) <e43a00ed-2b7d-497c-aa95-e30cbc04c04a@googlegroups.com> <557056f9$0$13009$c3e8da3$5496439d@news.astraweb.com> <87a8wf5z4l.fsf@elektro.pacujo.net> <mkpnqm$gfn$1@reader1.panix.com> <874mmn5xbb.fsf@elektro.pacujo.net> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.185.1433461888.13271.python-list@python.org> (permalink) |
On Thu, 04 Jun 2015 18:04:56 +0300, Marko Rauhamaa <marko@pacujo.net>
declaimed the following:
>
>Yes, but that would be a shift from the 1970's notion:
>
> In pass-by-value, the actual parameter is evaluated. The value of the
> actual parameter is then stored in a new location allocated for the
> function parameter.
>
Except that this does NOT happen with common Python. Python doesn't
"store in a new location"...
>>> def func(parm):
... print id(parm), id(a), parm is a
... parm = 6
... print id(parm), id(a), parm is a
...
>>> a = 3
>>> func(a)
4145800 4145800 True
4145728 4145800 False
>>> print a, id(a)
3 4145800
>>>
In the first print, "parm" and "a" ARE THE SAME OBJECT
After the assignment to parm, "parm" and "a" are no longer the same
object.
In your "1970's notion", "parm" and "a" should already be different
object by the time of the first print statement.
In common Python, id() basically returns the address of the object. "a"
is a reference to an object with the value "3"... On entry to func(),
"parm" is aso a reference to the same object (same address/ID).
But after the assignment, "parm" is now a reference to a different
object.
Python does not expose the old "mailboxes" concept to the user... That
is: where the languages of the 50s-70s all tied variable names to fixed
addresses (boxes) in memory, and assignment copies the contents of one box
to another box (and this applies also to parameter passing), Python instead
has a pile of "objects", a bunch of names on "post-it notes" (with strings
attached to them), and assignment works by moving the string from one
object to another object -- the location of the name does not change, only
the other end of the string changes what object it names.
--
Wulfraed Dennis Lee Bieber AF6VN
wlfraed@ix.netcom.com HTTP://wlfraed.home.netcom.com/
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Can Python function return multiple data? fl <rxjwg98@gmail.com> - 2015-06-02 14:27 -0700
Re: Can Python function return multiple data? Joel Goldstick <joel.goldstick@gmail.com> - 2015-06-02 17:35 -0400
Re: Can Python function return multiple data? sohcahtoa82@gmail.com - 2015-06-02 14:40 -0700
Re: Can Python function return multiple data? John Gordon <gordon@panix.com> - 2015-06-02 21:40 +0000
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-03 09:56 +1000
Re: Can Python function return multiple data? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2015-06-03 15:56 +0200
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-04 07:35 +1000
Re: Can Python function return multiple data? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-03 22:56 +0100
Re: Can Python function return multiple data? sohcahtoa82@gmail.com - 2015-06-03 15:28 -0700
Re: Can Python function return multiple data? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-06-03 21:30 -0400
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-04 11:52 +1000
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-04 23:47 +1000
Re: Can Python function return multiple data? Marko Rauhamaa <marko@pacujo.net> - 2015-06-04 17:25 +0300
Re: Can Python function return multiple data? Grant Edwards <invalid@invalid.invalid> - 2015-06-04 14:37 +0000
Re: Can Python function return multiple data? Marko Rauhamaa <marko@pacujo.net> - 2015-06-04 18:04 +0300
Re: Can Python function return multiple data? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-06-04 19:51 -0400
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 03:11 +1000
Re: Can Python function return multiple data? Marko Rauhamaa <marko@pacujo.net> - 2015-06-04 20:30 +0300
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 08:37 +1000
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-04 13:30 -0400
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 08:31 +1000
Re: Can Python function return multiple data? Grant Edwards <invalid@invalid.invalid> - 2015-06-04 18:38 +0000
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 08:52 +1000
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-05 09:04 +1000
Re: Can Python function return multiple data? Grant Edwards <invalid@invalid.invalid> - 2015-06-05 02:02 +0000
Re: Can Python function return multiple data? Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2015-06-05 09:11 +0200
Re: Can Python function return multiple data? Marko Rauhamaa <marko@pacujo.net> - 2015-06-05 12:27 +0300
Re: Can Python function return multiple data? Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2015-06-05 14:04 +0200
Re: Can Python function return multiple data? BartC <bc@freeuk.com> - 2015-06-04 21:52 +0100
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 09:13 +1000
Re: Can Python function return multiple data? BartC <bc@freeuk.com> - 2015-06-05 01:16 +0100
Re: Can Python function return multiple data? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-05 02:40 +0100
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 11:48 +1000
Re: Can Python function return multiple data? BartC <bc@freeuk.com> - 2015-06-05 11:06 +0100
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-05 07:44 +1000
Re: Can Python function return multiple data? BartC <bc@freeuk.com> - 2015-06-05 10:51 +0100
Re: Can Python function return multiple data? ElChino <elchino@cnn.cn> - 2015-06-04 17:37 +0200
Re: Can Python function return multiple data? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-06-04 19:57 -0400
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-04 13:26 -0400
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 08:16 +1000
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-04 18:59 -0400
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 12:37 +1000
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-04 20:16 -0700
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 21:06 +1000
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-05 06:29 -0700
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-06 07:59 +1000
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-05 20:20 -0700
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-05 23:28 -0400
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-05 22:28 -0700
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-06 15:43 +1000
Lawful != Mutable (was Can Python function return multiple data?) Rustom Mody <rustompmody@gmail.com> - 2015-06-07 08:49 -0700
Re: Lawful != Mutable (was Can Python function return multiple data?) Chris Angelico <rosuav@gmail.com> - 2015-06-08 02:07 +1000
Re: Lawful != Mutable (was Can Python function return multiple data?) Rustom Mody <rustompmody@gmail.com> - 2015-06-07 09:20 -0700
Re: Lawful != Mutable (was Can Python function return multiple data?) Chris Angelico <rosuav@gmail.com> - 2015-06-08 02:34 +1000
Re: Lawful != Mutable (was Can Python function return multiple data?) Rustom Mody <rustompmody@gmail.com> - 2015-06-20 18:59 -0700
Re: Lawful != Mutable (was Can Python function return multiple data?) Chris Angelico <rosuav@gmail.com> - 2015-06-21 12:32 +1000
Re: Lawful != Mutable (was Can Python function return multiple data?) Rustom Mody <rustompmody@gmail.com> - 2015-06-20 19:50 -0700
Re: Lawful != Mutable (was Can Python function return multiple data?) Laura Creighton <lac@openend.se> - 2015-06-21 11:14 +0200
Re: Lawful != Mutable (was Can Python function return multiple data?) Ron Adam <ron3200@gmail.com> - 2015-06-21 08:55 -0400
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-07 15:51 +1000
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-06 13:49 +1000
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-06 14:50 +1000
Re: Can Python function return multiple data? Chris Angelico <rosuav@gmail.com> - 2015-06-06 15:29 +1000
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-05 22:32 -0700
Re: Can Python function return multiple data? Dave Farrance <df@see.replyto.invalid> - 2015-06-06 07:52 +0100
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-07 15:53 +1000
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-05 08:21 -0400
Re: Can Python function return multiple data? Marko Rauhamaa <marko@pacujo.net> - 2015-06-05 16:37 +0300
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-04 19:07 -0700
Re: Can Python function return multiple data? Michael Torrie <torriem@gmail.com> - 2015-06-04 11:36 -0600
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-04 13:51 -0400
Re: Can Python function return multiple data? Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2015-06-04 20:17 +0200
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-05 08:45 +1000
Re: Can Python function return multiple data? Alain Ketterlin <alain@universite-de-strasbourg.fr.invalid> - 2015-06-05 08:59 +0200
Re: Can Python function return multiple data? Michael Torrie <torriem@gmail.com> - 2015-06-04 08:16 -0600
Re: Can Python function return multiple data? sohcahtoa82@gmail.com - 2015-06-05 11:55 -0700
Re: Can Python function return multiple data? random832@fastmail.us - 2015-06-04 01:01 -0400
Re: Can Python function return multiple data? Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-04 12:34 -0600
Re: Can Python function return multiple data? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-04 20:16 +0100
Re: Can Python function return multiple data? Serhiy Storchaka <storchaka@gmail.com> - 2015-06-04 09:56 +0300
Re: Can Python function return multiple data? fl <rxjwg98@gmail.com> - 2015-06-06 10:57 -0700
Re: Can Python function return multiple data? Rustom Mody <rustompmody@gmail.com> - 2015-06-06 21:35 -0700
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-07 15:47 +1000
Re: Can Python function return multiple data? Steven D'Aprano <steve@pearwood.info> - 2015-06-07 15:33 +1000
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