[issue25600] argparse, argument_default=argparse.SUPPRESS seems to have no effect

[mcer45]

New submission from mcer45:

The parameter argument_default=argparse.SUPPRESS seems to have no effect.
Example:

=====================================================================

help_dirs='ahoy

parser = argparse.ArgumentParser(
formatter_class=argparse.RawDescriptionHelpFormatter,
description='Makes the calendar for the "year"',
epilog=textwrap.dedent(help_dirs))
parser.add_argument("user", help='the user directory with the required
structure in ./')
parser.add_argument("year", type=int, help='the year for this calendar
and also the directory for the output')
parser.add_argument("-acc","--acc",
default='no',nargs='?',choices=['yes','no'],const='yes',
help='accomodate ratio according to the
cover photo, default=no')
parser.add_argument("--color",default='gold', choices=['gold'],
help='default color: gold')
args = parser.parse_args(['mc', '2015'])
print(args)
del parser
del args



parser = argparse.ArgumentParser(argument_default=argparse.SUPPRESS,
formatter_class=argparse.RawDescriptionHelpFormatter,
description='Makes the calendar for the "year"',
epilog=textwrap.dedent(help_dirs))
parser.add_argument("user", help='the user directory with the required
structure in ./')
parser.add_argument("year", type=int, help='the year for this calendar
and also the directory for the output')
parser.add_argument("-acc","--acc",
default='no',nargs='?',choices=['yes','no'],const='yes',
help='accomodate ratio according to the
cover photo, default=no')
parser.add_argument("--color",default='gold', choices=['gold'],
help='default color: gold')
args = parser.parse_args(['mc', '2015'])


===================================

The results in both cases are the same:
Namespace(acc='no', color='gold', user='mc', year=2015)

I hoped the defaults will be suppressed.

----------
components: Library (Lib)
messages: 254478
nosy: bethard, mcer45
priority: normal
severity: normal
status: open
title: argparse, argument_default=argparse.SUPPRESS seems to have no effect
type: behavior
versions: Python 3.5

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Python tracker <***@bugs.python.org>
<http://bugs.python.org/issue25600>
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