coordenadas a numeros de tiles

#!/usr/bin/python
"""Usage:

./coord2slippy.py lat lon
"""
import sys
import getopt

from math import log, tan, cos


def main():
    # parse command line options
    try:
        opts, args = getopt.getopt(sys.argv[1:], "h", ["help"])
    except getopt.error, msg:
        print msg
        print "for help use --help"
        sys.exit(2)
    # process options
    for o, a in opts:
        if o in ("-h", "--help"):
            print __doc__
            sys.exit(0)
    # process arguments
    try:
        lat = float(args[0])
        lon = float(args[1])
    except:
        print "for help use --help"
        sys.exit(0)

    xtile = (lon+180)/360
    sec = 1 / cos(lat)
    ytile = log(tan(lat) + sec)

    return 'perl tilesGen.pl xy %s %s'% (str(xtile), str(ytile))


if __name__ == "__main__":
    print main()