def insertDomain(self, domain, indegree=0, outdegree=0):
		'''增加一个域名'''
		cur = self.conn.cursor()
		cur.execute("INSERT INTO Domains VALUES (NULL,?,?,?)", (domain, indegree, outdegree))
		# 写入到文件中
		self.conn.commit()
def parsed_error_msg(self):
        """
        Sometimes, the error message we've received needs to be parsed into
        something more human readable

        The default behavior is to return the current error message as is.
        """
        return self.error_msg