cliff

Subcommand '--version' parameters are not supported

Bug #1619708 reported by Stephen Finucane
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Bug Description

I'm reworking some code to use cliff. I've modified the sample app to add the following file:

    $ cat demoapp/cliffdemo/api_db.py
    from cliff.command import Command

    class Sync(Command):
        """Sync the database up to the most recent version."""
        def get_parser(self, prog_name):
            parser = super(Sync, self).get_parser(prog_name)
            parser.add_argument(
                '--version', nargs='?', metavar='<version>', default=None,
                help='Database version')
            return parser

        def take_action(self, parsed_args):
            version = parsed_args.version
            self.app.stdout.write('syncing version "%s"\n' % version)
    $ git diff demoapp/setup.py
    diff --git a/demoapp/setup.py b/demoapp/setup.py
    index dd8695d..7562a7f 100644
    --- a/demoapp/setup.py
    +++ b/demoapp/setup.py
    @@ -60,6 +60,7 @@ setup(
                 'file = cliffdemo.show:File',
                 'show file = cliffdemo.show:File',
                 'unicode = cliffdemo.encoding:Encoding',
    + 'api-db_sync = cliffdemo.api_db:Sync',
             ],
         },

However, when I run this command it appears the '--version' parameter is parsed by the top level parser instead of being propagated down like the '--help' parser is.

    $ demoapp api-db sync --help
    usage: nova-manage api-db sync [-h] [--version [<version>]]

    Sync the database up to the most recent version.

    optional arguments:
      -h, --help show this help message and exit
      --version [<version>]
                            Database version

    $ demoapp api-db sync --version 2
    demoapp 0.1

This seems like a bug, to me: the '--version' parameter makes no sense in this location in a command and does not need to be reserved.

See original description
Revision history for this message
Stephen Finucane (stephenfinucane) wrote :

Updated to reflect impact to demoapp.

summary: - "reserved" options don't work with subcommands
+ Subcommand '--version' parameters are not supported
description: updated
Revision history for this message
Stephen Finucane (stephenfinucane) wrote :

Based on the argparse library, this shouldn't happen :/

    >>> import argparse
    >>> parser = argparse.ArgumentParser()
    >>> parser.add_argument('-g', '--global')
    _StoreAction(option_strings=['-g', '--global'], dest='global', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
    >>> subparsers = parser.add_subparsers(dest="subparser_name")
    >>> foo_parser = subparsers.add_parser('foo')
    >>> foo_parser.add_argument('-g', '--global', dest='foo_global')
    _StoreAction(option_strings=['-g', '--global'], dest='foo_global', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
    >>> foo_parser.add_argument('-c', '--count')
    _StoreAction(option_strings=['-c', '--count'], dest='count', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
    >>> args = parser.parse_args(['-g', 'xyz', 'foo', '--count', '42'])
    >>> parser.parse_args(['-g', 'xyz', 'foo', '--count', '42'])
    Namespace(count='42', foo_global=None, global='xyz', subparser_name='foo')
    >>> parser.parse_args(['foo', '-g', 'xyz', '--count', '42'])
    Namespace(count='42', foo_global='xyz', global=None, subparser_name='foo')
    >>> parser.add_argument('--version', action='version', version='0.1')
    _VersionAction(option_strings=['--version'], dest='version', nargs=0, const=None, default='==SUPPRESS==', type=None, choices=None, help="show program's version number and exit", metavar=None)
    >>> foo_parser.add_argument('--version', dest='foo_version')
    _StoreAction(option_strings=['--version'], dest='foo_version', nargs=None, const=None, default=None, type=None, choices=None, help=None, metavar=None)
    >>> parser.parse_args(['foo', '-g', 'xyz', '--count', '42', '--version', '2'])
    Namespace(count='42', foo_global='xyz', foo_version='2', global=None, subparser_name='foo')
    >>> parser.parse_args(['--version', '2', 'foo', '-g', 'xyz', '--count', '42'])
    0.1

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