Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!newsreader4.netcologne.de!news.netcologne.de!xlned.com!feeder5.xlned.com!newsfeed.xs4all.nl!newsfeed4.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: 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; 'parameters': 0.04; 'defaults': 0.07; 'modified': 0.07; 'arguments': 0.09; 'overwrite': 0.09; 'parsed': 0.09; 'skip:/ 10': 0.09; 'subject:parsing': 0.09; 'python': 0.11; '-tkc': 0.16; 'alvarez': 0.16; 'command-line': 0.16; 'from:addr:python.list': 0.16; 'from:addr:tim.thechases.com': 0.16; 'from:name:tim chase': 0.16; 'given,': 0.16; 'processing)': 0.16; 'specifying': 0.16; 'subject:argparse': 0.16; 'variable.': 0.16; 'wrote:': 0.18; 'seems': 0.21; 'command': 0.22; 'config': 0.24; 'specify': 0.24; "haven't": 0.24; 'environment': 0.24; "i've": 0.25; 'script': 0.25; 'first,': 0.26; 'switch': 0.26; 'least': 0.26; '(for': 0.26; 'header:In-Reply-To:1': 0.27; 'easier': 0.31; 'file': 0.32; 'skip:m 30': 0.32; 'option': 0.32; 'skip:d 20': 0.34; 'there': 0.35; 'doing': 0.36; 'charset:us-ascii': 0.36; 'subject:?': 0.36; 'should': 0.36; 'whatever': 0.38; 'to:addr:python-list': 0.38; 'rather': 0.38; 'to:addr:python.org': 0.39; 'name': 0.63; 'alone,': 0.84; 'eduardo': 0.84; 'order:': 0.84; 'received:50.22': 0.84 Date: Sat, 31 Aug 2013 12:50:16 -0500 From: Tim Chase To: python-list@python.org Subject: Re: argparse - specify order of argument parsing? In-Reply-To: References: X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - boston.accountservergroup.com X-AntiAbuse: Original Domain - python.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tim.thechases.com X-Get-Message-Sender-Via: boston.accountservergroup.com: none X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 40 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1377971352 news.xs4all.nl 15897 [2001:888:2000:d::a6]:50486 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:53373 On 2013-08-31 13:11, Eduardo Alvarez wrote: > When using argparse, is there a way to specify in what order > arguments get parsed? I am writing a script whose parameters can be > modified in the following order: > > Defaults -> config file -> command-line switches. > > However, I want to give the option of specifying a config file > using a command line switch as well, so logically, that file should > be parsed before any other arguments are applied. However, it seems > that parse_args() parses arguments in the order they're given, so > if the config file switch is not given first, the config file will > overwrite whatever was in the command-line switches, which should > have higher priority. While I haven't come up with a good solution using argparse/optparse alone, I've found that it's easier (for processing) to specify the config file as an environment variable. So rather than doing my_prog.py -c /path/to/config.ini arg1 arg2 ... I just do MY_PROG_CONF=/path/to/config.ini my_prog.py arg1 arg2 ... ...at least on *nix systems; on Win32, it's c:\temp> set MY_PROG_CONF=c:\path\to\config.ini c:\temp> python my_prog.py arg1 arg2 ... Then you just intercept the config-file name from os.environ: config_file = os.environ.get( "MY_PROG_CONF", default_ini_location) -tkc