[Python]Marshmallow 代碼

• schema.dump和schema.load

schema.dump()方法返回一個MarshResult的對象，marshmallow官方API說dump和load方法返回的都是dict對象，但查看源碼，MarshResult對象是一個namedtuple.

## marshmallow::schema.py

### line 25 ####

#: Return type of :meth:`Schema.dump` including serialized data and errors
MarshalResult = namedtuple('MarshalResult', ['data', 'errors']) #: Return type of :meth:`Schema.load`, including deserialized data and errors
UnmarshalResult = namedtuple('UnmarshalResult', ['data', 'errors'])

我在跑官方Example的時候，這裏是有問題的

try: data = quote_schema.load(json_data) except ValidationError as err: return jsonify(err.messages), 422 first, last = data['author']['first'], data['author']['last'] # 此處代碼報錯， TypeError: tuple indices must be integers or slices, not str

namedtuple經過result['data']['xxx']的方法沒法訪問對象信息

可是經過result.data['xxx']倒是OK的。Python Doc裏對namedtuple的問方式也是"."訪問。好像能夠理解爲name是namedtuple的一個attribute，

>>> # Basic example
>>> Point = namedtuple('Point', ['x', 'y']) >>> p = Point(11, y=22)     # instantiate with positional or keyword arguments
>>> x, y = p                # unpack like a regular tuple
>>> x, y (11, 22) >>> p.x + p.y # fields also accessible by name
33
>>> p                       # readable __repr__ with a name=value style
Point(x=11, y=22)