Print the coordinates of all the astronomical objects in a LEMON database

export-coordinates.py

#! /usr/bin/env python

""" Take a LEMONdB file and print to standard output the right ascension and
declination of all the astronomical objects. """

# Author: Victor Terron (c) 2015
# Email: `echo vt2rron1iaa32s | tr 132 @.e`
# License: GNU GPLv3

from __future__ import division
from __future__ import print_function
from __future__ import absolute_import
from __future__ import unicode_literals

import argparse
import os.path
import sys

# Fix until LEMON is installed system-wide
LEMON_DIR = os.path.expanduser("~/lemon/")
sys.path.insert(0, LEMON_DIR)

# LEMON modules
import database

if __name__ == "__main__":

    # https://stackoverflow.com/a/12151325/184363
    parser = argparse.ArgumentParser(
        description='Export coordinates of objects in a LEMON database',
        )

    parser.add_argument('db_path', metavar='LEMON_DB', type=str,
                        help="the LEMON database")

    args = parser.parse_args()

    if not os.path.exists(args.db_path):
        msg = "Error: input LEMONdB does not exist"
        sys.exit(msg)

    db = database.LEMONdB(args.db_path)
    print("Stars: {0}".format(len(db)))
    # Export all light curves
    star_ids = db.star_ids

    for star_id in star_ids:
        ra, dec = db.get_star(star_id)[2:4]
        print("{0:.12}\t{1:.12}".format(ra, dec))