Script to output download link for MGEX data

cddis.py

#!/usr/bin/env python

import argparse
import datetime
import dateutil.parser


def parse_opts():
    parser = argparse.ArgumentParser(add_help=False)
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument('-h', '--hourly',
                       help='Retrieve hourly data',
                       action='store_true',
                       dest='hourly')
    group.add_argument('-d', '--daily',
                       help='Retrieve daily data',
                       action='store_true',
                       dest='daily')
    parser.add_argument('-g', '--glonass',
                        action='store_true',
                        dest='is_glonass')
    parser.add_argument('--help',
                        help='show this help message and exit',
                        action='help')
    parser.add_argument('time',
                        help='the date/time to get the URL for')
    return parser


def hourly(timestamp_str):
    timestamp = dateutil.parser.parse(timestamp_str)
    fmt = '%Y/%j/hour/%jm.%yn.Z'
    return timestamp.strftime(fmt)


def daily(timestamp_str, is_glonass=False):
    if is_glonass:
        # For GLONASS
        suffix = 'g'
    else:
        # For GPS
        suffix = 'n'
    timestamp = dateutil.parser.parse(timestamp_str)
    fmt = '%Y/%j/%y{0}/brdc%j0.%y{0}.Z'.format(suffix)
    return timestamp.strftime(fmt)


def main():
    parser = parse_opts()
    args = parser.parse_args()

    if args.daily:
        url_prefix = 'ftp://cddis.nasa.gov/gnss/data/daily/'
        url = daily(args.time, args.is_glonass)
    else:
        url_prefix = 'ftp://cddis.nasa.gov/gnss/data/hourly/'
        url = hourly(args.time)
    print(url_prefix + url)


if __name__ == '__main__':
    main()