python之SQLAlchemy > 类型错误 : 'instancemethod' object does not support item assignment

这是我得到的:

 
from sqlalchemy import * 
from sqlalchemy.orm import * 
from web.models.card import * 
connectionString = "postgresql://www:www@localhost/prod" 
databaseEngine = create_engine(connectionString) 
sessionFactory = sessionmaker(autoflush = True, autocommit = False, bind = databaseEngine) 
session = sessionFactory() 
CardsCollection = session.query(card).all() 
_content = {} 
for index in range(0, len(CardsCollection)): 
    c = CardsCollection[index] 
    _content[index] = c 
print json.dumps(_content) 

这里是错误:

 
Traceback (most recent call last): 
  File "/home/src/py/raspberry/src/dictionaryTest.py", line 15, in  
    CardsCollection = session.query(card).all() 
  File "/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/query.py", line 1453, in all 
    return list(self) 
  File "/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/query.py", line 1676, in instances 
    rows = [process[0](row, None) for row in fetch] 
  File "/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/mapper.py", line 2234, in _instance 
    populate_state(state, dict_, row, isnew, only_load_props) 
  File "/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/mapper.py", line 2113, in populate_state 
    populator(state, dict_, row) 
  File "/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/strategies.py", line 127, in new_execute 
    dict_[key] = row[col] 
TypeError: 'instancemethod' object does not support item assignment 

有人可以帮我解决这个问题吗？我已经尝试了一些东西，并研究了字典是如何工作的……但它并没有让我大吃一惊。

[编辑奇怪的分辨率] 显然，覆盖卡片模型上的 self.__dict__(self) 方法就是这样做的。不过，我不完全确定为什么。

请您参考如下方法:

__dict__ 是 special attribute保持实例的当前状态，用方法覆盖它肯定会导致麻烦。