Multiple positional arguments with Python and argparse

Question

I\'m trying to use argparse to parse the command line arguments for a program I\'m working on. Essentially, I need to support multiple positional arguments spread within the opt

Answer 1

The 'append' action makes more sense with an optional:

parser.add_argument('-i', '--input',action='append')
parser.parse_args(['-i','fileone', '-a', '-i','filetwo', '-b', '-i','filethree'])

You can interleave optionals with separate positionals ('input1 -a input2 -b input3'), but you cannot interleave optionals within one multiitem positional. But you can accomplish this with a two step parse.

import argparse
parser1 = argparse.ArgumentParser()
parser1.add_argument('-a', action='store_true')
parser1.add_argument('-b', action='store_true')
parser2 = argparse.ArgumentParser()
parser2.add_argument('input', nargs='*')

ns, rest = parser1.parse_known_args(['fileone', '-a', 'filetwo', '-b', 'filethree'])
# Namespace(a=True, b=True), ['fileone', 'filetwo', 'filethree']

ns = parser2.parse_args(rest, ns)
# Namespace(a=True, b=True, input=['fileone', 'filetwo', 'filethree'])

http://bugs.python.org/issue14191 is a proposed patch that will do this with single call to:

parser.parse_intermixed_args(['fileone', '-a', 'filetwo', '-b', 'filethree'])