Path: csiph.com!news.swapon.de!fu-berlin.de!uni-berlin.de!not-for-mail
From: Ben Finney <ben+python@benfinney.id.au>
Newsgroups: comp.lang.python
Subject: Re: Question about math.pi is mutable
Date: Tue, 10 Nov 2015 06:52:07 +1100
Lines: 22
Message-ID: <mailman.187.1447098741.16136.python-list@python.org>
References: <n1kshk$brb$1@dont-email.me> <878u69zxww.fsf@elektro.pacujo.net> <n1l3kd$5ma$1@dont-email.me> <563eba85$0$1611$c3e8da3$5496439d@news.astraweb.com> <n1n8mc$33l$1@dont-email.me> <87ziyowy83.fsf@elektro.pacujo.net> <n1nb0f$atn$1@dont-email.me> <mailman.135.1446998410.16136.python-list@python.org> <n1o25a$3s3$1@dont-email.me> <mailman.142.1447005691.16136.python-list@python.org> <n1o5sl$joc$1@dont-email.me> <mailman.152.1447024427.16136.python-list@python.org> <n1on71$san$1@dont-email.me> <8537wghwjb.fsf@benfinney.id.au> <CAPTjJmo=4p3DnvcLY_whdzaiy1t-sTyok20U9M0nQsNCg9_E=Q@mail.gmail.com> <85y4e8ggrj.fsf@benfinney.id.au> <CAPTjJmqaTQy397xgSjQsC2Bu8mxDQTvGsryp0e6nDk6Le688=A@mail.gmail.com> <85twowgfm6.fsf@benfinney.id.au> <CAPTjJmq--XE006MzxNe_3d_rmOP9GYxM_AxMF7Nh3d3RQbBx4g@mail.gmail.com> <mailman.160.1447031104.16136.python-list@python.org> <n1qivn$o17$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
X-Trace: news.uni-berlin.de dYK7AQNDQeXTO9QJhx5OAw0LWyPJjLhGkpC8J0B5rtGA==
Cancel-Lock: sha1:tKmg9OAfURs4SBV0Q6cfS9nCYGg=
Return-Path: <python-python-list@m.gmane.org>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.001
X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'compiler': 0.05; 'subject:Question': 0.05; 'attributes': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'appropriate': 0.14; 'value.': 0.15; 'bind': 0.16; "module's": 0.16; 'namespace,': 0.16; 'received:80.91.229.3': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'attribute': 0.18; 'somewhere': 0.24; 'module': 0.25; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'lifetime': 0.29; 'code': 0.30; 'relative': 0.30; "can't": 0.32; 'done': 0.35; "isn't": 0.35; 'there': 0.36; 'to:addr:python- list': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'delete': 0.38; 'to:addr:python.org': 0.40; 'different': 0.63; '8bit%:21': 0.70; '_o__)': 0.84; 'received:125': 0.84; 'updated,': 0.84
X-Injected-Via-Gmane: http://gmane.org/
X-Gmane-NNTP-Posting-Host: jigong.madmonks.org
X-Public-Key-ID: 0xAC128405
X-Public-Key-Fingerprint: 517C F14B B2F3 98B0 CB35  4855 B8B2 4C06 AC12 8405
X-Public-Key-URL: http://www.benfinney.id.au/contact/bfinney-pubkey.asc
X-Post-From: Ben Finney <bignose+hates-spam@benfinney.id.au>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux)
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.20+
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://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: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Xref: csiph.com comp.lang.python:98550

BartC <bc@freeuk.com> writes:

> On 09/11/2015 01:04, Ben Finney wrote:
> > There isn't a way for the compiler to *know*, in all cases, whether
> > module attributes will be updated during the lifetime of the program
>
> In what way can an attribute be updated, other than deleting it
> altogether?

* Bind a new name to a value.
* Re-bind an existing name to a different value.
* Delete an existing name.

Any of those can be done at run-time, in any module's namespace, by
arbitrary code somewhere in the program.

-- 
 \        “Sane people have an appropriate perspective on the relative |
  `\     importance of foodstuffs and human beings. Crazy people can't |
_o__)                 tell the difference.” —Paul Z. Myers, 2010-04-18 |
Ben Finney