fields.py 文件源码

def __get__(self, instance, instance_type=None):
        if instance is not None:
            value = instance._data.get(self.attr_name)
            if value is None:
                value = copy.deepcopy(self.field.default)
                instance._data[self.attr_name] = value
            if isinstance(value, dict):
                value = ObjectDict(value)
            if value and not isinstance(value, (dict, list, tuple)) and \
                    six.callable(self.field.converter):
                value = self.field.converter(value)
            return value
        return self.field