Using the same option multiple times in Python’s argparse

Here’s a parser that handles a repeated 2 argument optional – with names defined in the metavar:

parser=argparse.ArgumentParser()
parser.add_argument('-i','--input',action='append',nargs=2,
    metavar=('url','name'),help='help:')

In [295]: parser.print_help()
usage: ipython2.7 [-h] [-i url name]

optional arguments:
  -h, --help            show this help message and exit
  -i url name, --input url name
                        help:

In [296]: parser.parse_args('-i one two -i three four'.split())
Out[296]: Namespace(input=[['one', 'two'], ['three', 'four']])

This does not handle the 2 or 3 argument case (though I wrote a patch some time ago for a Python bug/issue that would handle such a range).

How about a separate argument definition with nargs=3 and metavar=('url','name','other')?

The tuple metavar can also be used with nargs="+" and nargs="*"; the 2 strings are used as [-u A [B ...]] or [-u [A [B ...]]].