Groups > comp.lang.python > #20781

Re: namespace question

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Date	Thu, 23 Feb 2012 22:35:07 -0800
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Subject	Re: namespace question
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On Thu, Feb 23, 2012 at 9:55 PM, xixiliguo <wangbo.red@gmail.com> wrote:
> c = [1, 2, 3, 4, 5]
> class TEST():
>    c = [5, 2, 3, 4, 5]

That line creates a class (i.e. "static") variable, which is unlikely
to be what you want. Instance variables are normally created in the
body of an __init__() method.

>    def add( self ):
>        c[0] = 15
>
> a = TEST()
>
>
> a.add()
>
> print( c, a.c, TEST.c )
>
> result :
> [15, 2, 3, 4, 5] [5, 2, 3, 4, 5] [5, 2, 3, 4, 5]
>
>
> why a.add() do not update c in Class TEST? but update c in main file

Python is not Java (or similar). To refer to instance variables, you
must explicitly use `self`; i.e. use "self.c[0] = 15" in add().

I would recommend reviewing the relevant section of the Python tutorial:
http://docs.python.org/tutorial/classes.html

Cheers,
Chris

Thread

namespace question xixiliguo <wangbo.red@gmail.com> - 2012-02-23 21:55 -0800
  Re: namespace question Chris Rebert <clp2@rebertia.com> - 2012-02-23 22:35 -0800
  Re: namespace question Jean-Michel Pichavant <jeanmichel@sequans.com> - 2012-02-24 12:56 +0100
  Re: namespace question David <dwblas@gmail.com> - 2012-02-24 10:08 -0800
    Re: namespace question Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-24 22:25 +0000
      Re: namespace question Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-02-25 00:39 +0000
        Re: namespace question Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-25 01:38 +0000
      Re: namespace question Ben Finney <ben+python@benfinney.id.au> - 2012-02-26 19:47 +1100
        Re: namespace question Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-26 13:40 +0000
          Re: namespace question Ben Finney <ben+python@benfinney.id.au> - 2012-02-28 22:36 +1100
            Re: namespace question Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-28 14:06 +0000

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