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Re: Why do class methods always need 'self' as the first parameter?

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> On Aug 31, 5:35 pm, "T. Goodchild" <tgoodch...@gmail.com> wrote:


>> So why is 'self' necessary on class methods?
>> 
>> Just curious about the rationale behind this part of the language.

When instance variables are accessed with the 'self.varname' syntax, it is clear to the programmer that an instance variable is accessed, and not some global.  Other languages have weird syntax conventions like that you have to prepend all instance attributes with an '@', and in languages like C++ where there is not necessarily such a syntactic requirement, many programmers use ad-hoc constructs like '_varname' or 'm_varname' to make the distinction clear.


>> It seems to me that the
>> most common practice is that class methods *almost always* operate on
>> the instance that called them.  It would make more sense to me if this
>> was assumed by default, and for "static" methods (methods that are
>> part of a class, but never associated with a specific instance) to be
>> labelled instead.

Yes, you have a point there. My personal preference would be to optimize for the most common case, while exceptions to the norm are still possible, but perhaps a bit more verbose.

Greetings

-- 
"Learn to value yourself, which means: fight for your happiness."  - Ayn Rand      

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Why do class methods always need 'self' as the first parameter? "T. Goodchild" <tgoodchild@gmail.com> - 2011-08-31 07:35 -0700
  Re: Why do class methods always need 'self' as the first parameter? John Gordon <gordon@panix.com> - 2011-08-31 14:54 +0000
    Re: Why do class methods always need 'self' as the first parameter? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-09-01 02:06 +1000
      Re: Why do class methods always need 'self' as the first parameter? Grant Edwards <invalid@invalid.invalid> - 2011-08-31 16:20 +0000
  Re: Why do class methods always need 'self' as the first parameter? Emile van Sebille <emile@fenx.com> - 2011-08-31 08:01 -0700
  Re: Why do class methods always need 'self' as the first parameter? Neil Cerutti <neilc@norwich.edu> - 2011-08-31 15:05 +0000
  Re: Why do class methods always need 'self' as the first parameter? Javier Collado <javier.collado@gmail.com> - 2011-08-31 17:10 +0200
  Re: Why do class methods always need 'self' as the first parameter? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-09-01 01:41 +1000
    Re: Why do class methods always need 'self' as the first parameter? Chris Torek <nospam@torek.net> - 2011-08-31 20:15 +0000
      Re: Why do class methods always need 'self' as the first parameter? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-09-01 10:48 +1000
        Re: Why do class methods always need 'self' as the first parameter? Chris Angelico <rosuav@gmail.com> - 2011-09-01 11:47 +1000
        Re: Why do class methods always need 'self' as the first parameter? Eric Snow <ericsnowcurrently@gmail.com> - 2011-08-31 20:07 -0600
        Re: Why do class methods always need 'self' as the first parameter? Chris Torek <nospam@torek.net> - 2011-09-01 02:20 +0000
      Re: Why do class methods always need 'self' as the first parameter? Piet van Oostrum <piet@vanoostrum.org> - 2011-09-05 16:15 +0200
        Re: Why do class methods always need 'self' as the first parameter? Chris Torek <nospam@torek.net> - 2011-09-06 01:10 +0000
          Re: Why do class methods always need 'self' as the first parameter? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-09-06 14:31 +1000
  Re: Why do class methods always need 'self' as the first parameter? Terry Reedy <tjreedy@udel.edu> - 2011-08-31 12:30 -0400
  RE: Why do class methods always need 'self' as the first parameter? "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2011-08-31 13:12 -0400
    Re: Why do class methods always need 'self' as the first parameter? Piet van Oostrum <piet@vanoostrum.org> - 2011-09-08 01:01 +0200
  Re: Why do class methods always need 'self' as the first parameter? Chris Rebert <clp2@rebertia.com> - 2011-08-31 11:31 -0700
  Re: Why do class methods always need 'self' as the first parameter? Ian Kelly <ian.g.kelly@gmail.com> - 2011-08-31 15:52 -0600
  Re: Why do class methods always need 'self' as the first parameter? Terry Reedy <tjreedy@udel.edu> - 2011-08-31 18:40 -0400
  Re: Why do class methods always need 'self' as the first parameter? UncleLaz <andrei.lisnic@gmail.com> - 2011-09-01 03:40 -0700
    Re: Why do class methods always need 'self' as the first parameter? Michiel Overtoom <motoom@xs4all.nl> - 2011-09-01 13:23 +0200
  Re: Why do class methods always need 'self' as the first parameter? John Roth <johnroth1@gmail.com> - 2011-09-01 05:45 -0700
    Re: Why do class methods always need 'self' as the first parameter? Ian Kelly <ian.g.kelly@gmail.com> - 2011-09-01 08:26 -0600
      Re: Why do class methods always need 'self' as the first parameter? John Roth <johnroth1@gmail.com> - 2011-09-02 10:51 -0700
        Re: Why do class methods always need 'self' as the first parameter? Ian Kelly <ian.g.kelly@gmail.com> - 2011-09-02 14:30 -0600
          Re: Why do class methods always need 'self' as the first parameter? John Roth <johnroth1@gmail.com> - 2011-09-02 15:30 -0700
  Re: Why do class methods always need 'self' as the first parameter? rantingrick <rantingrick@gmail.com> - 2011-09-05 20:58 -0700

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