Re: lambda in list comprehension acting funny

From	Dennis Lee Bieber <wlfraed@ix.netcom.com>
Subject	Re: lambda in list comprehension acting funny
Date	2012-07-13 13:47 -0400
Organization	> Bestiaria Support Staff <
References	<mailman.2006.1341988919.4697.python-list@python.org> <03943ea6-5914-4de4-821c-055bed1d5804@f9g2000pbd.googlegroups.com> <4fffc1fd$0$29965$c3e8da3$5496439d@news.astraweb.com> <dc19f10f-018f-4859-8882-bc47d4b91b73@oo8g2000pbc.googlegroups.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.2092.1342201638.4697.python-list@python.org> (permalink)

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On Fri, 13 Jul 2012 06:44:59 -0700 (PDT), rusi <rustompmody@gmail.com>
declaimed the following in gmane.comp.python.general:


> Heres a more appropriate analog
> 
> ------------------------------------------
> VERBOSE = True
> 
> def function(arg):
>     if VERBOSE:
>        print("calling function with arg %r" % arg)
>     process(arg)
> 
> def caller():
>     VERBOSE = False
>     function(1)
> 
> ---------------------------------------------
> Python semantics: function sees VERBOSE False

	Wrong... "function" still sees the module level VERBOSE with a value
of True, whereas "caller" created a local VERBOSE set to False. To get
your behavior needs:

	def caller():
		global VERBOSE
		VERBOSE = False
		function(1)


> Haskell semantics: function sees VERBOSE True
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
        wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

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lambda in list comprehension acting funny Daniel Fetchinson <fetchinson@googlemail.com> - 2012-07-11 08:41 +0200
  Re: lambda in list comprehension acting funny "Colin J. Williams" <cjw@ncf.ca> - 2012-07-11 06:28 -0400
    Re: lambda in list comprehension acting funny Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-11 10:34 -0600
      Re: lambda in list comprehension acting funny 88888 Dihedral <dihedral88888@googlemail.com> - 2012-07-11 20:39 -0700
        Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-12 03:51 +0000
          Re: lambda in list comprehension acting funny 88888 Dihedral <dihedral88888@googlemail.com> - 2012-07-11 22:04 -0700
            Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-12 06:18 +0000
              Re: lambda in list comprehension acting funny Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-12 08:40 +0100
      Re: lambda in list comprehension acting funny 88888 Dihedral <dihedral88888@googlemail.com> - 2012-07-11 20:39 -0700
  Re: lambda in list comprehension acting funny woooee <woooee@gmail.com> - 2012-07-11 11:38 -0700
    Re: lambda in list comprehension acting funny John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-11 13:21 -0700
      Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-12 00:52 +0000
      Re: lambda in list comprehension acting funny Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-11 21:05 -0400
        Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-12 03:53 +0000
          Re: lambda in list comprehension acting funny Terry Reedy <tjreedy@udel.edu> - 2012-07-12 00:24 -0400
          Re: lambda in list comprehension acting funny Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-12 00:39 -0400
            Re: lambda in list comprehension acting funny Robert Miles <robertmiles@teranews.com> - 2012-08-15 19:26 -0500
      Re: lambda in list comprehension acting funny John O'Hagan <research@johnohagan.com> - 2012-07-12 15:29 +1000
      Re: lambda in list comprehension acting funny Robert Kern <robert.kern@gmail.com> - 2012-07-12 10:06 +0100
    Re: lambda in list comprehension acting funny Hans Mulder <hansmu@xs4all.nl> - 2012-07-12 00:22 +0200
    Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-11 23:47 +0000
      Re: lambda in list comprehension acting funny Daniel Fetchinson <fetchinson@googlemail.com> - 2012-07-12 04:54 +0200
  Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-12 03:59 +0000
    Re: lambda in list comprehension acting funny Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-12 10:53 -0600
    Re: lambda in list comprehension acting funny Rotwang <sg552@hotmail.co.uk> - 2012-07-12 18:23 +0100
      Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-13 02:20 +0000
  Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-12 21:33 -0700
    Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-13 06:36 +0000
      Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-13 06:44 -0700
        Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-13 07:45 -0700
        RE: lambda in list comprehension acting funny "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-07-13 16:12 +0000
          Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-13 09:46 -0700
            Re: lambda in list comprehension acting funny Chris Angelico <rosuav@gmail.com> - 2012-07-14 03:20 +1000
          Re: lambda in list comprehension acting funny Hans Mulder <hansmu@xs4all.nl> - 2012-07-13 19:53 +0200
            RE: lambda in list comprehension acting funny "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-07-13 18:06 +0000
            Re: lambda in list comprehension acting funny Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-13 12:54 -0600
              Re: lambda in list comprehension acting funny Hans Mulder <hansmu@xs4all.nl> - 2012-07-13 21:26 +0200
              Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-14 23:29 +0000
                Re: lambda in list comprehension acting funny Chris Angelico <rosuav@gmail.com> - 2012-07-15 10:49 +1000
                Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-15 08:32 +0000
                Re: lambda in list comprehension acting funny Chris Angelico <rosuav@gmail.com> - 2012-07-15 18:44 +1000
                Re: lambda in list comprehension acting funny Hans Mulder <hansmu@xs4all.nl> - 2012-07-15 21:25 +0200
                Re: lambda in list comprehension acting funny Terry Reedy <tjreedy@udel.edu> - 2012-07-15 06:27 -0400
            Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-13 19:31 -0700
              Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-14 03:43 +0000
                Re: lambda in list comprehension acting funny rusi <rustompmody@gmail.com> - 2012-07-13 21:53 -0700
                Re: lambda in list comprehension acting funny Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-14 07:46 +0000
        Re: lambda in list comprehension acting funny Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-13 13:47 -0400

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