Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #52636

Re: Python getters and setters

Return-Path <python@mrabarnett.plus.com>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.002
X-Spam-Evidence '*H*': 1.00; '*S*': 0.00; 'python.': 0.02; 'subject:Python': 0.06; 'attribute': 0.07; 'method.': 0.07; 'suppose': 0.07; 'alternatives': 0.09; 'obj': 0.09; 'python': 0.11; 'def': 0.12; 'creates': 0.14; 'attributes,': 0.16; 'fits': 0.16; 'from:addr:mrabarnett.plus.com': 0.16; 'from:addr:python': 0.16; 'from:name:mrab': 0.16; 'instantiated': 0.16; 'length)': 0.16; 'length.': 0.16; 'message-id:@mrabarnett.plus.com': 0.16; 'public,': 0.16; 'received:84.93': 0.16; 'received:84.93.230': 0.16; 'wrote:': 0.18; 'users.': 0.18; 'previously': 0.22; 'header :User-Agent:1': 0.23; 'necessary.': 0.24; 'class.': 0.26; 'header :In-Reply-To:1': 0.27; 'easier': 0.31; 'piece': 0.31; 'class': 0.32; 'received:84': 0.35; 'but': 0.35; 'there': 0.35; '(e.g.,': 0.36; 'i.e.': 0.36; 'options:': 0.36; 'method': 0.36; 'two': 0.37; 'expected': 0.38; 'needed': 0.38; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'called': 0.40; 'users': 0.40; 'new': 0.61; 'first': 0.61; 'information': 0.63; 'such': 0.63; 'provide': 0.64; 'more': 0.64; 'deals': 0.65; 'within': 0.65; 'header:Reply- To:1': 0.67; 'reply-to:no real name:2**0': 0.71; 'information:': 0.72; 'potentially': 0.81; 'reply-to:addr:python.org': 0.84
X-CM-Score 0.00
X-CNFS-Analysis v=2.1 cv=ZMDuxxLb c=1 sm=1 tr=0 a=0nF1XD0wxitMEM03M9B4ZQ==:117 a=0nF1XD0wxitMEM03M9B4ZQ==:17 a=0Bzu9jTXAAAA:8 a=0kkAYlmtguIA:10 a=ihvODaAuJD4A:10 a=OUOv7kDek9cA:10 a=8nJEP1OIZ-IA:10 a=EBOSESyhAAAA:8 a=8AHkEIZyAAAA:8 a=RnqSfMZ_l9EA:10 a=W8xr5IaSuGQBU3VAaU4A:9 a=tkrSZkk8FLTP0LVr:21 a=rEGfNwTsYL5QWPo8:21 a=wPNLvfGTeEIA:10
X-AUTH mrabarnett:2500
Date Sat, 17 Aug 2013 18:10:25 +0100
From MRAB <python@mrabarnett.plus.com>
User-Agent Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8
MIME-Version 1.0
To python-list@python.org
Subject Re: Python getters and setters
References <227bd47c-0e86-4d65-985f-e59aa4f25294@googlegroups.com>
In-Reply-To <227bd47c-0e86-4d65-985f-e59aa4f25294@googlegroups.com>
Content-Type text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding 7bit
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.15
Precedence list
Reply-To python-list@python.org
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.17.1376759432.23369.python-list@python.org> (permalink)
Lines 22
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1376759432 news.xs4all.nl 15987 [2001:888:2000:d::a6]:56418
X-Complaints-To abuse@xs4all.nl
Path csiph.com!usenet.pasdenom.info!news.franciliens.net!feed.ac-versailles.fr!nerim.net!novso.com!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Xref csiph.com comp.lang.python:52636

Show key headers only | View raw


On 17/08/2013 17:53, Fernando Saldanha wrote:
> I am new to Python.
>
> I understand that it is "unpythonic" to write getters and setters, and that property() can be used if necessary.
>
> This deals with the case of attributes, but there are other kinds of information available within a class.
>
> Suppose my class contains an attribute called "data" that can potentially provide a lot of information that will be needed by class users. I have two options:
>
> 1) For each piece of information within data (e.g., length) I write a method that retrieves that information:
>
>      def data_length(self):
>          return len(self.data)
>
> 2) I do not create such a method. Users that are interested in that information will have to write len(obj.data), where obj is a previously instantiated object of my class.
>
> Which one of the two alternatives fits better with the Python philosophy? The first alternative is more work for me, creates a "heavier" class and may have slower performance, but makes things easier for the user and is more implementation independent.
>
If the attribute is public, i.e. the user is expected to write obj.data, 
then
len(obj.data) is the right way to get its length.

Back to comp.lang.python | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Python getters and setters Fernando Saldanha <fsaldan1@gmail.com> - 2013-08-17 09:53 -0700
  Re: Python getters and setters MRAB <python@mrabarnett.plus.com> - 2013-08-17 18:10 +0100
  Re: Python getters and setters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-17 17:18 +0000
    Re: Python getters and setters Tim Chase <python.list@tim.thechases.com> - 2013-08-17 12:31 -0500
    Re: Python getters and setters Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2013-08-18 00:52 +0200
      Re: Python getters and setters Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-17 23:40 +0000
        Re: Python getters and setters Chris Angelico <rosuav@gmail.com> - 2013-08-18 02:07 +0100
  Re: Python getters and setters Fernando Saldanha <fsaldan1@gmail.com> - 2013-08-17 22:26 -0700

csiph-web