Python argparse - Add argument to multiple subpars

问题:

My script defines one main parser and multiple subparsers. I want to apply the -p argument to some subparsers. So far the code looks like this:

parser = argparse.ArgumentParser(prog="myProg")
subparsers = parser.add_subparsers(title="actions")

parser.add_argument("-v", "--verbose",
                    action="store_true",
                    dest="VERBOSE",
                    help="run in verbose mode")

parser_create = subparsers.add_parser ("create", 
                                        help = "create the orbix environment")
parser_create.add_argument ("-p", 
                            type = int, 
                            required = True, 
                            help = "set db parameter")

# Update
parser_update = subparsers.add_parser ("update", 
                                        help = "update the orbix environment")
parser_update.add_argument ("-p", 
                            type = int, 
                            required = True, 
                            help = "set db parameter")

As you can see the add_arument ("-p") is repeated twice. I actually have a lot more subparsers. Is there a way to loop through the existing subparsers in order to avoid repetition?

For the record, I am using Python 2.7

回答1:

This can be achieved by defining a parent parser containing the common option(s):

[...]
parent_parser = argparse.ArgumentParser(add_help=False)
parent_parser.add_argument("-p", type=int, required=True,
                           help="set db parameter")
parser_create = subparsers.add_parser("create", parents=[parent_parser],
                                      help="create the orbix environment")
parser_update = subparsers.add_parser("update", parents=[parent_parser],
                                      help="update the orbix environment")

回答2:

You can also loop over the subparsers and add the same option to all of them.

parser = argparse.ArgumentParser(prog="myProg")
subparsers = parser.add_subparsers(title="actions")
parser.add_argument("-v", "--verbose",
                    action="store_true",
                    dest="VERBOSE",
                    help="run in verbose mode")

parser_create = subparsers.add_parser ("create", 
                                        help = "create the orbix environment")
parser_update = subparsers.add_parser ("update", 
                                        help = "update the orbix environment")

for subparser in [parser_create, parser_update]:
    subparser.add_argument ("-p", 
                            type = int, 
                            required = True, 
                            help = "set db parameter")

回答3:

You can loop over your subparsers in the folowing way.

for name, subp in subparsers.choices.items():
    print(subp)
    subp.add_argument(dest='g', help='Inpput for g variable', default='7')