Skeleton command line script

cmd_line_script.py

'''
Save this file to scripts/myprog.py then add these lines to setup.py:

    entry_points = {
        'console_scripts': [
            'myprog=fpoffline.scripts.myprog:main',
        ],
    }
'''
import argparse
import logging
import pdb
import traceback
import sys

def run(args):
    # raise an exception here to flag any error
    # return value is propagated to the shell
    return 0

def main():
    # https://docs.python.org/3/howto/argparse.html
    parser = argparse.ArgumentParser(
        description='Calculate per-exposure effective depths',
        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument('-v', '--verbose', action='store_true',
        help='provide verbose output on progress')
    parser.add_argument('--debug', action='store_true',
        help='provide verbose and debugging output')
    parser.add_argument('--logpath', type=str, metavar='PATH',
        help='Path where logging output should be written')
    parser.add_argument('--traceback', action='store_true',
        help='print traceback and enter debugger after an exception')
    args = parser.parse_args()

    # Configure logging.
    if args.debug:
        level = logging.DEBUG
    elif args.verbose:
        level = logging.INFO
    else:
        level = logging.WARNING
    logging.basicConfig(filename=args.logpath, level=level,
        format='%(asctime)s %(levelname)s %(message)s', datefmt='%Y%m%d %H:%M:%S')

    try:
        retval = run(args)
        sys.exit(retval)
    except Exception as e:
        if args.traceback:
            # https://stackoverflow.com/questions/242485/starting-python-debugger-automatically-on-error            
            extype, value, tb = sys.exc_info()
            traceback.print_exc()
            pdb.post_mortem(tb)
        else:
            print(e)
            sys.exit(-1)
 
if __name__ == '__main__':
    main()