Create a LatLon object from a pair of strings.
    Inputs:
        lat_str (str) - string representation of a latitude (e.g. '5 52 59.88 N')
        lon_str (str) - string representation of a longitude (e.g. '162 4 59.88 W')
        format_str (str) - format in which the coordinate strings are given (e.g.
          for the above examples this would be 'd% %m% %S% %H'). See function
          string2geocoord for a detailed explanation on how to specify formats.
    Returns:
        A LatLon object initialized with coordinate data from lat_str and lon_str

def string2latlon(lat_str, lon_str, format_str):
    '''
    Create a LatLon object from a pair of strings.
    Inputs:
        lat_str (str) - string representation of a latitude (e.g. '5 52 59.88 N')
        lon_str (str) - string representation of a longitude (e.g. '162 4 59.88 W')
        format_str (str) - format in which the coordinate strings are given (e.g.
          for the above examples this would be 'd% %m% %S% %H'). See function
          string2geocoord for a detailed explanation on how to specify formats.
    Returns:
        A LatLon object initialized with coordinate data from lat_str and lon_str
    '''
    lat = string2geocoord(lat_str, Latitude, format_str)
    lon = string2geocoord(lon_str, Longitude, format_str)
    new_latlon = LatLon(lat = lat, lon = lon)
    return new_latlon