Re: Implicit conversion to boolean in if and while statements

References	(7 earlier) <mailman.2195.1342490275.4697.python-list@python.org> <5004ec84$0$11116$c3e8da3@news.astraweb.com> <mailman.2201.1342502395.4697.python-list@python.org> <50050f70$0$30002$c3e8da3$5496439d@news.astraweb.com> <500520FF.3010305@gmail.com>
Date	2012-07-17 18:32 +1000
Subject	Re: Implicit conversion to boolean in if and while statements
From	Chris Angelico <rosuav@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.2204.1342513982.4697.python-list@python.org> (permalink)

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On Tue, Jul 17, 2012 at 6:23 PM, Andrew Berg <bahamutzero8825@gmail.com> wrote:
> On 7/17/2012 2:08 AM, Steven D'Aprano wrote:
>> The default behaviour is that every object is something, hence true-like,
>> unless explicitly coded to be treated as false-like. Since both loggers
>> and functions are objects, they are true-like unless the default is
>> overridden.
> I am aware of the default behavior, but the reason for it still eludes me.

There has to be something. This way, you can use None in place of any
object, in the same way that a null pointer would be used in C; any
object is true, None isn't. What other default makes more sense?

ChrisA

Thread

Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-15 03:34 -0500
  Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-15 10:56 +0000
    Re: Implicit conversion to boolean in if and while statements Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-15 10:19 -0600
      Re: Implicit conversion to boolean in if and while statements Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-15 09:50 -0700
        Re: Implicit conversion to boolean in if and while statements Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-15 12:01 -0600
          Re: Implicit conversion to boolean in if and while statements Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-15 11:56 -0700
            Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 07:53 +1000
              Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 18:21 -0700
                Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 11:51 +1000
                Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 19:31 -0700
                Re: Implicit conversion to boolean in if and while statements Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-16 17:57 +0000
                Re: Implicit conversion to boolean in if and while statements Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-17 00:44 -0400
                Re: Implicit conversion to boolean in if and while statements Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-15 22:15 -0400
                Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 19:58 -0700
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 04:03 +0000
                Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 21:53 -0700
                Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 15:57 +1000
                Re: Implicit conversion to boolean in if and while statements alex23 <wuwei23@gmail.com> - 2012-07-16 00:21 -0700
                Re: Implicit conversion to boolean in if and while statements Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-17 00:18 -0400
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 06:25 +0000
                Re: Implicit conversion to boolean in if and while statements Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-17 05:38 -0400
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 02:58 +0000
                Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 13:05 +1000
                Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 20:21 -0700
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 04:20 +0000
                Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 22:03 -0700
                Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 16:00 +1000
                Re: Implicit conversion to boolean in if and while statements alex23 <wuwei23@gmail.com> - 2012-07-16 00:27 -0700
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 07:52 +0000
                Re: Implicit conversion to boolean in if and while statements Laszlo Nagy <gandalf@shopzeus.com> - 2012-07-16 23:26 +0200
                Re: Implicit conversion to boolean in if and while statements Laszlo Nagy <gandalf@shopzeus.com> - 2012-07-16 23:17 +0200
                Re: Implicit conversion to boolean in if and while statements Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-16 07:30 +0100
                Re: Implicit conversion to boolean in if and while statements Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-16 18:03 +0000
          Re: Implicit conversion to boolean in if and while statements Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-15 11:56 -0700
        Re: Implicit conversion to boolean in if and while statements Serhiy Storchaka <storchaka@gmail.com> - 2012-07-16 16:01 +0300
        Re: Implicit conversion to boolean in if and while statements rusi <rustompmody@gmail.com> - 2012-07-16 18:45 -0700
      Re: Implicit conversion to boolean in if and while statements Rick Johnson <rantingrickjohnson@gmail.com> - 2012-07-15 09:50 -0700
      Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 02:13 +0000
        Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-15 19:41 -0700
          Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-16 12:58 +1000
          Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 08:05 +0000
        Re: Implicit conversion to boolean in if and while statements Ethan Furman <ethan@stoneleaf.us> - 2012-07-16 11:13 -0700
          Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 06:14 +0000
    Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-15 12:02 -0500
      Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-16 02:38 +0000
        Re: Implicit conversion to boolean in if and while statements Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-16 13:28 -0400
          Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 01:12 +0000
            Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 01:13 +0000
        Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-16 15:33 -0500
        Re: Implicit conversion to boolean in if and while statements Ethan Furman <ethan@stoneleaf.us> - 2012-07-16 13:54 -0700
          Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 00:43 +0000
            Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-16 20:57 -0500
              Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 04:39 +0000
                Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-17 00:19 -0500
                Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 07:08 +0000
                Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-17 03:23 -0500
                Re: Implicit conversion to boolean in if and while statements alex23 <wuwei23@gmail.com> - 2012-07-17 18:35 -0700
                Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-17 18:32 +1000
                Re: Implicit conversion to boolean in if and while statements Laszlo Nagy <gandalf@shopzeus.com> - 2012-07-17 14:43 +0200
                Re: Implicit conversion to boolean in if and while statements Laszlo Nagy <gandalf@shopzeus.com> - 2012-07-17 14:59 +0200
                Re: Implicit conversion to boolean in if and while statements Terry Reedy <tjreedy@udel.edu> - 2012-07-17 13:57 -0400
                Re: Implicit conversion to boolean in if and while statements Ethan Furman <ethan@stoneleaf.us> - 2012-07-17 05:35 -0700
            Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-17 12:13 +1000
    Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-15 12:16 -0500
    Re: Implicit conversion to boolean in if and while statements Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-15 11:45 -0600
    Re: Implicit conversion to boolean in if and while statements Terry Reedy <tjreedy@udel.edu> - 2012-07-15 16:09 -0400
    Re: Implicit conversion to boolean in if and while statements Terry Reedy <tjreedy@udel.edu> - 2012-07-15 16:28 -0400
    Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-16 20:22 -0500
      Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 04:11 +0000
        Re: Implicit conversion to boolean in if and while statements Ranting Rick <rantingrickjohnson@gmail.com> - 2012-07-16 21:18 -0700
          Re: Implicit conversion to boolean in if and while statements Chris Angelico <rosuav@gmail.com> - 2012-07-17 14:24 +1000
        Re: Implicit conversion to boolean in if and while statements Andrew Berg <bahamutzero8825@gmail.com> - 2012-07-16 23:44 -0500
    Re: Implicit conversion to boolean in if and while statements Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-17 04:47 +0000
  Re: Implicit conversion to boolean in if and while statements John Nagle <nagle@animats.com> - 2012-07-17 00:26 -0700

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