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


Groups > comp.lang.python > #99300

Re: [argparse] optional parameter without --switch

Path csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From Peter Otten <__peter__@web.de>
Newsgroups comp.lang.python
Subject Re: [argparse] optional parameter without --switch
Date Tue, 24 Nov 2015 09:36:38 +0100
Organization None
Lines 25
Message-ID <mailman.93.1448354220.2291.python-list@python.org> (permalink)
References <3p4FFS0cRdz5vNy@dovecot03.posteo.de>
Mime-Version 1.0
Content-Type text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding 7Bit
X-Trace news.uni-berlin.de AaHC2jyUU3YPVXFcIV2kuggbyVQh988rWZ0oevqTaAYg==
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; 'subject:: [': 0.03; 'python3': 0.05; 'optional': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'python': 0.10; 'argparse': 0.16; 'received:80.91.229.3': 0.16; 'received:dip0.t-ipconnect.de': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'received:t-ipconnect.de': 0.16; 'subject:argparse': 0.16; 'wrote:': 0.16; 'subject:] ': 0.19; '(on': 0.22; 'parameter': 0.22; 'parser': 0.22; '(like': 0.23; 'import': 0.24; 'script': 0.25; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'skip:# 10': 0.27; 'switch': 0.27; 'cat': 0.29; 'optional.': 0.29; 'error.': 0.31; 'url:python': 0.33; 'url:dev': 0.35; 'should': 0.36; 'url:org': 0.36; 'url:library': 0.36; 'to:addr:python-list': 0.36; 'two': 0.37; 'received:org': 0.37; 'skip:p 20': 0.38; 'means': 0.39; 'test': 0.39; 'to:addr:python.org': 0.40; 'received:de': 0.40
X-Injected-Via-Gmane http://gmane.org/
X-Gmane-NNTP-Posting-Host p57bd99e9.dip0.t-ipconnect.de
User-Agent KNode/4.13.3
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:99300

Show key headers only | View raw


c.buhtz@posteo.jp wrote:

> I want to call (on bash) a Python script in this two ways without any
> error.
> 
>     ./arg.py
>     ./arg.py TEST
> 
> It means that the parameter (here with the value `TEST`) should be
> optional. With argparse I only know a way to create optional paramters
> when they have a switch (like `--name`).

$ cat tmp.py
#!/usr/bin/env python3
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("name", nargs="?")
print("name =", parser.parse_args().name)
$ ./tmp.py
name = None
$ ./tmp.py 42
name = 42

https://docs.python.org/dev/library/argparse.html#nargs

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


Thread

Re: [argparse] optional parameter without --switch Peter Otten <__peter__@web.de> - 2015-11-24 09:36 +0100

csiph-web