Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
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 0.000
X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'from:addr:yahoo.co.uk': 0.04; 'true,': 0.05; 'subject:code': 0.07; 'executed': 0.09; 'lawrence': 0.09; 'means,': 0.09; 'operand': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'language.': 0.14; '"or"': 0.16; 'a()': 0.16; 'b()': 0.16; 'cleaner': 0.16; 'cui': 0.16; 'guys,': 0.16; 'pythonic': 0.16; 'really?': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'roy': 0.16; 'subject:python': 0.16; 'followed': 0.16; 'language': 0.16; 'wrote:': 0.18; 'code.': 0.18; 'hey': 0.18; 'header:User- Agent:1': 0.23; 'second': 0.26; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; "doesn't": 0.30; 'code': 0.31; 'bunch': 0.31; 'something': 0.35; 'requirement': 0.35; 'there': 0.35; 'false': 0.36; 'otherwise.': 0.36; 'thanks': 0.36; 'should': 0.36; 'to:addr:python-list': 0.38; 'sure': 0.39; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'first': 0.61; 'our': 0.64; 'more': 0.64; 'frank': 0.68; 'smith': 0.68; 'evaluate': 0.72; 'article': 0.77; 'do:': 0.91
X-Injected-Via-Gmane: http://gmane.org/
To: python-list@python.org
From: Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject: Re: cascading python executions only if return code is 0
Date: Sun, 22 Dec 2013 19:31:21 +0000
References: <mailman.4500.1387739297.18130.python-list@python.org> <roy-12E94D.14175322122013@news.panix.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Gmane-NNTP-Posting-Host: host-78-146-15-252.as13285.net
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.2.0
In-Reply-To: <roy-12E94D.14175322122013@news.panix.com>
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.15
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>
Newsgroups: comp.lang.python
Message-ID: <mailman.4504.1387740695.18130.python-list@python.org>
Lines: 31
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1387740695 news.xs4all.nl 2848 [2001:888:2000:d::a6]:58454
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:62546

On 22/12/2013 19:17, Roy Smith wrote:
> In article <mailman.4500.1387739297.18130.python-list@python.org>,
>   Frank Cui <ycui@outlook.com> wrote:
>
>> hey guys,
>> I have a requirement where I need to sequentially execute a bunch of
>> executions, each execution has a return code. the followed executions should
>> only be executed if the return code is 0. is there a cleaner or more pythonic
>> way to do this other than the following ?
>> if a() == 0:    if b() == 0:        c()
>> Thanks for your input.
>> frank 		 	   		
>
> Yup!  Just do:
>
> a() or b() or c()
>
> The "or" operation has what's known as "short-circuit" semantics.  That
> means, if the first operand is true, it doesn't evaluate the second
> operand.  Just make sure that a(), b(), and c() all return something
> which is true if they succeed and false otherwise.
>

Really? :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence