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pythoncommand-lineargparse

Get selected subcommand with argparse


When I use subcommands with python argparse, I can get the selected arguments.

parser = argparse.ArgumentParser()
parser.add_argument('-g', '--global')
subparsers = parser.add_subparsers()   
foo_parser = subparsers.add_parser('foo')
foo_parser.add_argument('-c', '--count')
bar_parser = subparsers.add_parser('bar')
args = parser.parse_args(['-g', 'xyz', 'foo', '--count', '42'])
# args => Namespace(global='xyz', count='42')

So args doesn't contain 'foo'. Simply writing sys.argv[1] doesn't work because of the possible global args. How can I get the subcommand itself?


Solution

  • The very bottom of the Python docs on argparse sub-commands explains how to do this:

    >>> parser = argparse.ArgumentParser()
    >>> parser.add_argument('-g', '--global')
    >>> subparsers = parser.add_subparsers(dest="subparser_name") # this line changed
    >>> foo_parser = subparsers.add_parser('foo')
    >>> foo_parser.add_argument('-c', '--count')
    >>> bar_parser = subparsers.add_parser('bar')
    >>> args = parser.parse_args(['-g', 'xyz', 'foo', '--count', '42'])
    >>> args
    Namespace(count='42', global='xyz', subparser_name='foo')
    

    You can also use the set_defaults() method referenced just above the example I found.