p-with-fixed-help.py

#!/usr/bin/env python
import argparse
import ConfigParser

conf_parser = argparse.ArgumentParser(
    # Turn off help, so we print all options in response to -h
        add_help=False
        )
conf_parser.add_argument("-c", "--conf_file",
                         help="Specify config file", metavar="FILE")
args, remaining_argv = conf_parser.parse_known_args()
defaults = {
    "option1" : "some default",
    "option2" : "some other default",
    }
if args.conf_file:
    config = ConfigParser.SafeConfigParser(defaults)
    config.read([args.conf_file])
    defaults = dict(config.items("Defaults"))

# Don't surpress add_help here so it will handle -h
parser = argparse.ArgumentParser(
    # Inherit options from config_parser
    parents=[conf_parser],
    # print script description with -h/--help
    description=__doc__,
    # Don't mess with format of description
    formatter_class=argparse.RawDescriptionHelpFormatter,
    )
parser.set_defaults(**defaults)
parser.add_argument("--option1", help="some option")
parser.add_argument("--option2", help="some other option")
args = parser.parse_args(remaining_argv)
print args