Issue 18349: argparse usage should preserve () in metavars such as range(20) (original) (raw)

Created on 2013-07-03 06:16 by paul.j3, last changed 2022-04-11 14:57 by admin.

Messages (5)

msg192222 - (view)

Author: paul j3 (paul.j3) *

Date: 2013-07-03 06:16

As discussed in issue 16468, a metavar may be used to provide an alternative representation of a choices option. However if a metvar like 'range(20)' is used, usage formatter strips off the '()'.

>>> parser.add_argument('foo', type=int, 
    choices=range(20), metavar='range(0,20)')
>>> parser.format_usage()
# expect: 'usage: PROG [-h] range(0,20)\n'
# actual: 'usage: PROG [-h] range0,20\n'

This is done by a line in the help formater that removes excess mutually exclusive group notation:

HelpFormatter._format_actions_usage
   ...
   text = _re.sub(r'\(([^|]*)\)', r'\1', text)

A solution is to change this line to distinguish between a case like ' (...)' and 'range(...)'

text = _re.sub(r'( )\(([^|]*)\)', r'\1\2', text)

msg192717 - (view)

Author: paul j3 (paul.j3) *

Date: 2013-07-09 03:08

I just posted a patch to http://bugs.python.org/issue16468 that uses (and tests) this fix.

msg193077 - (view)

Author: paul j3 (paul.j3) *

Date: 2013-07-15 07:15

This issue should also preserve a metavar like: '(one)two', i.e. '(' at the start.

In http://bugs.python.org/issue10984 these _re replacements are applied to individual action strings as well as the whole usage line. So if () are to be removed from '[-h] (-y)', they should also be removed from '(-y)'.

msg193188 - (view)

Author: paul j3 (paul.j3) *

Date: 2013-07-16 20:34

I just submitted at patch to http://bugs.python.org/issue11874 that takes care of this issue as well.

I rewrote _format_actions_usage() so it formats the parts directly, so there is no need cleanup or parse the full text string.

msg408214 - (view)

Author: Irit Katriel (iritkatriel) *

Date: 2021-12-10 15:48

Reproduced on 3.11:

import argparse parser = argparse.ArgumentParser() parser.add_argument('foo', type=int, choices=range(20), metavar='range(0,20)') _StoreAction(option_strings=[], dest='foo', nargs=None, const=None, default=None, type=<class 'int'>, choices=range(0, 20), help=None, metavar='range(0,20)') parser.format_usage() 'usage: [-h] range0,20\n'

History

Date

User

Action

Args

2022-04-11 14:57:47

admin

set

github: 62549

2021-12-10 15:48:45

iritkatriel

set

nosy: + iritkatriel

messages: +
versions: + Python 3.9, Python 3.10, Python 3.11, - Python 3.4

2013-07-16 20:34:49

paul.j3

set

messages: +

2013-07-15 07:15:36

paul.j3

set

messages: +

2013-07-09 03:08:49

paul.j3

set

messages: +

2013-07-03 06:19:39

paul.j3

set

type: behavior
components: + Library (Lib)
versions: + Python 3.4

2013-07-03 06:16:51

paul.j3

create