Storing Deque Data fro class level access returns empty

Question

I have the snippet below where I want to create objects with a nested structure so that when I append values to obj1._data then _datatwo is updated. Idea is that _datatwo is a growing OrderedDict with each instances of DataOne object.

from collections import OrderedDict, deque

class DataOne:
    def __init__(self):
        self._data = deque()
        self._dataqueue = OrderedDict()
        self._dataqueue["key"] = self._data

    @property
    def get_data(self):
        return self._data

class DataTwo:

    _datatwo = OrderedDict()

    def __init__(self):
        pass

    @classmethod
    def append_value(cls, dataone: DataOne):
        cls._datatwo["key"] = dataone

obj1 = DataOne()
obj2 = DataTwo()

for i in range(10):
    obj1._data.append(i)
DataTwo.append_value(obj1)
print(DataTwo._datatwo['key'].get_data)

However this schema doesn't work with big data (10000 entries are enough). deque returns correct values inside the loop but when I call from outside deque returns always empty.