classification
Title: In argparse subparser's option goes to parent parser
Type: behavior Stage:
Components: Library (Lib) Versions: Python 3.6
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: py.user
Priority: normal Keywords:

Created on 2015-06-20 00:52 by py.user, last changed 2015-06-20 00:52 by py.user.

Messages (1)
msg245536 - (view) Author: py.user (py.user) * Date: 2015-06-20 00:52
Some misleading behaviour found with option belonging.
It's possible to put one option twicely, so it can set different
parameters accoding to context.

A source of argt.py for test:

#!/usr/bin/env python3

import argparse

parser = argparse.ArgumentParser()
parser.add_argument('-f', dest='tf', action='store_true')

subs = parser.add_subparsers()

sub = subs.add_parser('cmd')
sub.add_argument('-f', dest='cf', action='store_true')

parser.add_argument('arg')

args = parser.parse_args()
print(args)


Running it:

[guest@localhost debug]$ ./argt.py cmd 1
Namespace(arg='1', cf=False, tf=False)
[guest@localhost debug]$ ./argt.py cmd -f 1
Namespace(arg='1', cf=True, tf=False)
[guest@localhost debug]$ ./argt.py cmd 1 -f
Namespace(arg='1', cf=False, tf=True)
[guest@localhost debug]$


ISTM, options for the top parser should be placed between program name and subcommand name in any order, and options for the subcommand should follow subcommand in any order. The argument of top parser should be moved to the end and parsed after all options were placed correctly.
History
Date User Action Args
2015-06-20 00:52:43py.usercreate