[New-bugs-announce] [issue15613] argparse ArgumentDefaultsHelpFormatter interacts badly with --arg and nargs=+

[Alex Jurkiewicz]

New submission from Alex Jurkiewicz:

Sample code:

#!/usr/bin/env python
import argparse

print("\n\narg=foo, nargs=+")
parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('foo', nargs='+', help='foos', default=['foo1', 'foo2'])
parser.print_help()

print("\n\narg=foo, nargs=*")
parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('foo', nargs='*', help='foos', default=['foo1', 'foo2'])
parser.print_help()

print("\n\narg=--foo, nargs=+")
parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('--foo', nargs='+', help='foos', default=['foo1', 'foo2'])
parser.print_help()

print("\n\narg=--foo, nargs=*")
parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('--foo', nargs='*', help='foos', default=['foo1', 'foo2'])
parser.print_help()


The first example's help text for 'foo' is missing "(default: ['foo1', 'foo2'])". I tested 2.7.2, 2.7.3, 3.2.3.

----------
components: Library (Lib)
messages: 167854
nosy: Alex.Jurkiewicz
priority: normal
severity: normal
status: open
title: argparse ArgumentDefaultsHelpFormatter interacts badly with --arg and nargs=+
type: behavior
versions: Python 2.7, Python 3.2

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue15613>
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