fields.py 文件源码

def proxied(self):
        if not self._proxied:
            if self.bind_args:
                field_name, parent = self.bind_args

                if hasattr(parent, 'child') and parent.child is self:
                    # RecursiveField nested inside of a ListField
                    parent_class = parent.parent.__class__
                else:
                    # RecursiveField directly inside a Serializer
                    parent_class = parent.__class__

                assert issubclass(parent_class, BaseSerializer)

                if self.to is None:
                    proxied_class = parent_class
                else:
                    try:
                        module_name, class_name = self.to.rsplit('.', 1)
                    except ValueError:
                        module_name, class_name = parent_class.__module__, self.to

                    try:
                        proxied_class = getattr(
                            importlib.import_module(module_name), class_name)
                    except Exception as e:
                        raise ImportError(
                            'could not locate serializer %s' % self.to, e)

                # Create a new serializer instance and proxy it
                proxied = proxied_class(**self.init_kwargs)
                proxied.bind(field_name, parent)
                self._proxied = proxied

        return self._proxied