def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def getLenp3(self):
        p1 = self.p1
        ret = p1.distance(self.p2)
        return ret