def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def test_optional_arguments(self):
        self.assertEqual(self.myfunc('a'), self.expected)
        self.assertEqual(self.myfunc('a', 5), self.expected)
        self.assertEqual(self.myfunc('a', second=5), self.expected)
        self.assertEqual(self.myfunc('a', 5, 5), self.expected)
        self.assertEqual(self.myfunc('a', fourth=[]), self.expected)