Python google.appengine.ext.db 模块，GeoPt() 实例源码

def safe_geopoint(geo_str):
    '''
    geo_str as lat,lon
    returns a db.GeoPt if possible and if not None
    '''
    gp = None
    if geo_str is None:
        return None
    try:
        gp = db.GeoPt(geo_str)
    except Exception, e:
        pass
        logging.error(str(e))
    if gp and gp.lat == 0.0 and gp.lon == 0.0:
        gp = None
    return gp