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


Groups > comp.lang.python > #16051

Re: Close as Many Files/External resourcs as possible in the face of exceptions

Path csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed5.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; 'context': 0.04; 'situation.': 0.05; 'received:verizon.net': 0.07; 'terry': 0.07; 'exception.': 0.09; 'exceptions': 0.09; "object's": 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:80.91.229.12': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'received:lo.gmane.org': 0.09; 'am,': 0.12; 'exception': 0.12; 'called,': 0.16; 'close()': 0.16; 'constructor.': 0.16; 'exceptions.': 0.16; 'failure.': 0.16; 're- raise': 0.16; 'reedy': 0.16; 'subject: \n ': 0.16; 'subject:possible': 0.16; 'wrote:': 0.18; 'instance': 0.18; 'jan': 0.19; '(or': 0.22; 'header:In-Reply-To:1': 0.22; 'ignore': 0.26; 'function': 0.27; 'raise': 0.28; 'looks': 0.29; 'second': 0.29; 'outer': 0.30; 'parent': 0.30; 'least': 0.30; 'list': 0.32; 'objects': 0.32; 'header:User-Agent:1': 0.33; 'header:X -Complaints-To:1': 0.33; 'object': 0.33; 'to:addr:python-list': 0.34; 'it.': 0.34; 'possible,': 0.34; 'all.': 0.34; 'preserve': 0.34; 'subject:/': 0.35; '...': 0.36; 'two': 0.37; 'but': 0.37; 'could': 0.37; 'received:org': 0.38; 'some': 0.38; 'fail': 0.39; 'files': 0.39; 'to:addr:python.org': 0.40; 'custom': 0.61; 'further': 0.64; 'strategy': 0.64; 'here': 0.65; 'imagine': 0.71; 'subject:face': 0.84
X-Injected-Via-Gmane http://gmane.org/
To python-list@python.org
From Terry Reedy <tjreedy@udel.edu>
Subject Re: Close as Many Files/External resourcs as possible in the face of exceptions
Date Mon, 21 Nov 2011 16:48:37 -0500
References <2e8d4372-393d-4c55-aa6e-6c9afd6c8ef2@n35g2000yqf.googlegroups.com> <jadf1g$hpp$1@speranza.aioe.org>
Mime-Version 1.0
Content-Type text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding 7bit
X-Gmane-NNTP-Posting-Host pool-74-109-121-73.phlapa.fios.verizon.net
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0
In-Reply-To <jadf1g$hpp$1@speranza.aioe.org>
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.2936.1321912144.27778.python-list@python.org> (permalink)
Lines 28
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1321912144 news.xs4all.nl 6916 [2001:888:2000:d::a6]:42056
X-Complaints-To abuse@xs4all.nl
Xref x330-a1.tempe.blueboxinc.net comp.lang.python:16051

Show key headers only | View raw


On 11/21/2011 7:09 AM, Mel Wilson wrote:
> GZ wrote:
>> Here is my situation. A parent object owns a list of files (or other
>> objects with a close() method). The close() method can sometimes fail
>> and raise an exception. When the parent object's close() method is
>> called, it needs to close down as many files it owns as possible, even
>> if the close() function of some files fail. I also want to re-raise at
>> least one of the original exceptions so that the outer program can
>> handle it.
> [ ... ]
>>
>> It will re-raise the first exception and preserve the context and
>> close as many other files as possible while ignoring any further
>> exceptions.
>>
>> But this looks really awkward. And in the case that two files fail to
>> close, I am not sure the best strategy is to ignore the second failure.
>
> I imagine you could save any caught exception instances in a list and
> study them later.

Yes, I would raise a custom exception instance that takes such a list of 
failures in its constructor. Give it a custom __str__ method to display 
them all.

-- 
Terry Jan Reedy

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


Thread

Close as Many Files/External resourcs as possible in the face of exceptions GZ <zyzhu2000@gmail.com> - 2011-11-20 21:46 -0800
  Re: Close as Many Files/External resourcs as possible in the face of exceptions Mel Wilson <mwilson@the-wire.com> - 2011-11-21 07:09 -0500
    Re: Close as Many Files/External resourcs as possible in the face of exceptions Terry Reedy <tjreedy@udel.edu> - 2011-11-21 16:48 -0500

csiph-web