__getattr__ vs property

demo.py

 class test(dict):
    def __init__(self):
        self['data'] = {}

    def __setattr__(self, name, value):
        self['data'][name] = value

    def __getattr__(self, name):
        try:
            return self['data'][name]
        except KeyError:
            raise AttributeError(name)


    @property
    def foo(self):
        return 'foos'