Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!eternal-september.org!feeder.eternal-september.org!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed6.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <t@jollybox.de>
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; 'syntax': 0.03; 'expressions': 0.07; 'subject:code': 0.07; 'alain': 0.09; 'correct,': 0.09; 'defined,': 0.09; 'reference:': 0.09; 'restriction': 0.09; 'def': 0.10; 'language': 0.14; '...,': 0.16; 'expressions)': 0.16; 'op1': 0.16; 'op2': 0.16; 'operators,': 0.16; 'opn': 0.16; 'received:192.168.1.50': 0.16; 'syntactic': 0.16; 'wrote:': 0.17; 'certainly': 0.17; "shouldn't": 0.17; '(or': 0.18; 'equivalent': 0.20; 'bit': 0.21; 'supposed': 0.21; 'header :In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; '(which': 0.26; 'raw': 0.27; '"in': 0.29; 'comparison': 0.29; 'consult': 0.29; 'writes:': 0.29; "we're": 0.30; 'evaluation': 0.30; 'right?': 0.33; 'to:addr:python-list': 0.33; 'done': 0.34; 'pm,': 0.35; 'there': 0.35; 'except': 0.36; 'but': 0.36; 'two': 0.37; 'subject:: ': 0.38; 'to:addr:python.org': 0.39; 'received:192': 0.39; 'received:192.168': 0.40; 'most': 0.61; 'face': 0.61; 'first': 0.61; 'received:62': 0.62; 'thomas': 0.62; 'more': 0.63; '(single': 0.84; 'from:addr:t': 0.84; 'received:62.75': 0.84; 'technically': 0.91; 'refuse': 0.93
Date: Sat, 30 Jun 2012 23:35:19 +0200
From: Thomas Jollans <t@jollybox.de>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1
MIME-Version: 1.0
To: python-list@python.org
Subject: Re: code review
References: <mailman.1623.1340939177.4697.python-list@python.org> <6c39594f-79cb-4d4f-967e-bbc3f68cdbdf@f8g2000pbf.googlegroups.com> <4fed59b7$0$29978$c3e8da3$5496439d@news.astraweb.com> <mailman.1631.1340982202.4697.python-list@python.org> <EaAHr.369967$of1.132220@fx06.am4> <mailman.1651.1341052165.4697.python-list@python.org> <2662370.TGmo96CKe1@PointedEars.de> <mailman.1658.1341085147.4697.python-list@python.org> <VlJHr.500117$jl.112442@fx19.am4> <mailman.1659.1341089444.4697.python-list@python.org> <87wr2oecf6.fsf@dpt-info.u-strasbg.fr>
In-Reply-To: <87wr2oecf6.fsf@dpt-info.u-strasbg.fr>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.12
Precedence: list
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.1660.1341092123.4697.python-list@python.org>
Lines: 24
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1341092123 news.xs4all.nl 6972 [2001:888:2000:d::a6]:46541
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:24704

On 06/30/2012 11:07 PM, Alain Ketterlin wrote:
> Thomas Jollans <t@jollybox.de> writes:
> 
>>>>>> def is_valid_password(password):
>>>>>>     return mud.minpass <= len(password) <= mud.maxpass
> 
>> Which of the two comparisons is done first anyway?
>> "In the face of ambiguity, refuse the temptation to guess."
> 
> There is no ambiguity. See the language reference:

Of course it's technically clearly defined, but the syntax isn't
explicit. To know what the order is (or whether there is an order!) one
has to consult the language reference (which shouldn't be necessary), or
make an educated guess, which would almost certainly be correct, but
we're supposed to refuse the temptation to guess, right?

> "Formally, if a, b, c, ..., y, z are expressions and op1, op2, ..., opN
> are comparison operators, then a op1 b op2 c ... y opN z is equivalent
> to a op1 b and b op2 c and ... y opN z, except that each expression is
> evaluated at most once."
> 
> The last restriction (single evaluation of involved expressions) makes
> this a bit more than raw syntactic sugar.