Re: checking if a list is empty

From	rusi <rustompmody@gmail.com>
Newsgroups	comp.lang.python
Subject	Re: checking if a list is empty
Date	2011-05-14 00:45 -0700
Organization	http://groups.google.com
Message-ID	<d72b37d6-bf1e-4cec-94e3-88baca894fd9@35g2000prp.googlegroups.com> (permalink)
References	(5 earlier) <931adaF9g1U1@mid.individual.net> <roy-FC7816.07362712052011@news.panix.com> <4dcc785e$0$29980$c3e8da3$5496439d@news.astraweb.com> <d423a455-f14e-4cb4-8744-0a49259c9c86@34g2000pru.googlegroups.com> <4dce31b3$0$29980$c3e8da3$5496439d@news.astraweb.com>

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On May 14, 12:39 pm, Steven D'Aprano <steve
+comp.lang.pyt...@pearwood.info> wrote:
> On Thu, 12 May 2011 23:46:12 -0700, rusi wrote:
> > Mathematics has existed for millenia. Hindu-arabic numerals (base-10
> > numbers) have been known for about one millennium
> > The boolean domain is only a 100 years old. Unsurprisingly it is not
> > quite 'first-class' yet: See
> >http://www.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1070.html
> > [Lifted fromhttp://c2.com/cgi/wiki?EqualVsTrueFalse]
>
> Th money-quote as regards using arbitrary objects in truth tests:
>
>     [quote]
>     All this changed with the introduction of the two-element
>     boolean domain {true, false} which provides the vocabulary
>     needed to assign values to boolean expressions: 3<4 is a
>     way for writing true, 3>4 is a way for writing false,
>     whereas the value of x>0 depends on the value of x ...
>     [end quote]
>
> In Python, [1, 2, 3] is another way of writing true, and [] is another
> way of writing false. Similarly with any other arbitrary objects.

Well so is [1,2] another way of writing True

And then we get the interesting result that
(True = True) is False

Thread

checking if a list is empty Jabba Laci <jabba.laci@gmail.com> - 2011-05-06 02:36 -0400
  Re: checking if a list is empty Richard Thomas <chardster@gmail.com> - 2011-05-06 03:34 -0700
  Re: checking if a list is empty scattered <tooscattered@gmail.com> - 2011-05-06 14:57 -0700
    Re: checking if a list is empty Philip Semanchuk <philip@semanchuk.com> - 2011-05-06 18:21 -0400
    Re: checking if a list is empty Ian Kelly <ian.g.kelly@gmail.com> - 2011-05-06 17:51 -0600
      Re: checking if a list is empty Jon Clements <joncle@googlemail.com> - 2011-05-06 17:43 -0700
        Re: checking if a list is empty Hans Mulder <hansmu@xs4all.nl> - 2011-05-14 10:52 +0200
    Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-07 02:51 +0000
      Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-11 10:02 +0100
        Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-11 12:14 +0000
          Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-11 15:05 +0100
            Re: checking if a list is empty "D'Arcy J.M. Cain" <darcy@druid.net> - 2011-05-11 10:27 -0400
              Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-11 18:59 +0100
                Re: checking if a list is empty alex23 <wuwei23@gmail.com> - 2011-05-11 20:16 -0700
                Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-12 06:20 +0100
            Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-11 15:50 +0000
              Re: checking if a list is empty Chris Angelico <rosuav@gmail.com> - 2011-05-12 02:05 +1000
                Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-11 18:56 +0100
                Re: checking if a list is empty harrismh777 <harrismh777@charter.net> - 2011-05-11 16:13 -0500
          RE: checking if a list is empty "Prasad, Ramit" <ramit.prasad@jpmchase.com> - 2011-05-11 13:39 -0400
        Re: checking if a list is empty Roy Smith <roy@panix.com> - 2011-05-11 08:26 -0400
          Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-11 13:29 +0000
          Re: checking if a list is empty Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2011-05-12 17:44 +1200
            Re: checking if a list is empty Hans Georg Schaathun <hg@schaathun.net> - 2011-05-12 07:06 +0100
            Re: checking if a list is empty Roy Smith <roy@panix.com> - 2011-05-12 07:36 -0400
              Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-13 00:16 +0000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-12 23:46 -0700
                Re: checking if a list is empty Chris Rebert <clp2@rebertia.com> - 2011-05-13 01:02 -0700
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-13 03:58 -0700
                Re: checking if a list is empty Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2011-05-14 14:34 +1200
                Re: checking if a list is empty David Robinow <drobinow@gmail.com> - 2011-05-14 10:28 -0400
                Re: checking if a list is empty Roy Smith <roy@panix.com> - 2011-05-14 11:04 -0400
                Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-14 07:39 +0000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-14 00:45 -0700
                Re: checking if a list is empty Chris Angelico <rosuav@gmail.com> - 2011-05-14 23:42 +1000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-14 08:47 -0700
                Re: checking if a list is empty Chris Angelico <rosuav@gmail.com> - 2011-05-15 01:55 +1000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-14 10:43 -0700
                Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-14 17:29 -0400
                Re: checking if a list is empty Ben Finney <ben+python@benfinney.id.au> - 2011-05-15 09:26 +1000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-14 19:41 -0700
                Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-15 05:07 +0000
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-15 10:33 -0700
                Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-15 17:36 -0400
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-15 22:56 -0700
                Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-16 00:36 +0000
                Re: checking if a list is empty harrismh777 <harrismh777@charter.net> - 2011-05-15 20:59 -0500
                Re: checking if a list is empty rusi <rustompmody@gmail.com> - 2011-05-15 22:40 -0700
                Re: checking if a list is empty harrismh777 <harrismh777@charter.net> - 2011-05-15 20:25 -0500
                Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-15 21:57 -0400
                Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-14 16:59 -0400
                Re: checking if a list is empty Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-15 05:00 +0000
                Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-14 16:53 -0400
          Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-12 15:37 -0400
          Re: checking if a list is empty Terry Reedy <tjreedy@udel.edu> - 2011-05-12 18:00 -0400
  Re: checking if a list is empty Raymond Hettinger <python@rcn.com> - 2011-05-06 15:52 -0700

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