[Python]Marshmallow 代碼

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• 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 errorsMarshalResult = namedtuple(‘MarshalResult‘, [‘data‘, ‘errors‘])#: Return type of :meth:`Schema.load`, including deserialized data and errorsUnmarshalResult = namedtuple(‘UnmarshalResult‘, [‘data‘, ‘errors‘])

我在跑官方Example的時候，這裡是有問題的

    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通過result[‘data‘][‘xxx‘]的方法無法訪問對象資訊

但是通過result.data[‘xxx‘]卻是OK的。Python Doc裡對namedtuple的問方式也是"."訪問。好像可以理解為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 name33>>> p                       # readable __repr__ with a name=value stylePoint(x=11, y=22)

 

[Python]Marshmallow 代碼