Minimal python program with logging and argparse.

bootstrap_cmdline.py

#!/usr/bin/env python
# encoding: utf-8


"""Minimal python commad line."""

import sys
import argparse
import logging


module = sys.modules['__main__'].__file__
log = logging.getLogger(module)


def parse_command_line(argv):
    """Parse command line argument. See -h option

    :param argv: arguments on the command line must include caller file name.
    """
    formatter_class = argparse.RawDescriptionHelpFormatter
    parser = argparse.ArgumentParser(description=module,
                                     formatter_class=formatter_class)
    parser.add_argument("--version", action="version",
                        version="%(prog)s {}".format(__version__))
    parser.add_argument("-v", "--verbose", dest="verbose_count",
                        action="count", default=0,
                        help="increases log verbosity for each occurence.")
    parser.add_argument('-o', metavar="output",
                        type=argparse.FileType('w'), default=sys.stdout,
                        help="redirect output to a file")
    parser.add_argument('input', metavar="input", nargs='+', 
                        argparse.REMAINDER, help="input if any...")
    arguments = parser.parse_args(argv[1:])
    # Sets log level to WARN going more verbose for each new -v.
    log.setLevel(max(3 - arguments.verbose_count, 0) * 10)
    return arguments


def main():
    """Main program. Sets up logging and do some work."""
    logging.basicConfig(stream=sys.stderr, level=logging.DEBUG,
                        format='%(name)s (%(levelname)s): %(message)s')
    try:
        arguments = parse_command_line(sys.argv)
        # Do something with arguments.
    except KeyboardInterrupt:
        log.error('Program interrupted!')
    finally:
        logging.shutdown()

if __name__ == "__main__":
    sys.exit(main())