test_types_extras.py 文件源码

def test_adapt_subclass(self):
        from psycopg2.extras import json, Json

        class DecimalEncoder(json.JSONEncoder):
            def default(self, obj):
                if isinstance(obj, Decimal):
                    return float(obj)
                return json.JSONEncoder.default(self, obj)

        class MyJson(Json):
            def dumps(self, obj):
                return json.dumps(obj, cls=DecimalEncoder)

        curs = self.conn.cursor()
        obj = Decimal('123.45')
        self.assertEqual(curs.mogrify("%s", (MyJson(obj),)), b"'123.45'")