Using @property to clone attributes initialized from superclass

I want to create a class inheriting from a superclass that keeps track of the already initialized class attributes in the superclass. The @property decorator caught my eye and I tried to implement it (see example below).

class MyClass():

    def __init__(self):
        self.data="myinitialdata"

class MySubClass(MyClass):

    def __init__(self, myclass):
        super().__init__()
        self._myclass = myclass

    @property
    def data(self):
        return self._myclass.data

def main():
    new_myclass = MyClass()
    new_myclass.data="mynewdata"
    new_mysubclass = MySubClass(new_myclass)

    print(new_mysubclass.data)

if __name__=='__main__':
    main()

However, if I want to create a property of an already initialized attribute (in the superclass) I always receive an error that the attribute cannot be set:

AttributeError: can't set attribute 'data'

The code example works if I do not initialize data in MyClass:

class MyClass():

    def __init__(self):
        # self.data="myinitialdata"
        pass

class MySubClass(MyClass):

    def __init__(self, myclass):
        super().__init__()
        self._myclass = myclass

    @property
    def data(self):
        return self._myclass.data

def main():
    new_myclass = MyClass()
    new_myclass.data="mynewdata"
    new_mysubclass = MySubClass(new_myclass)

    print(new_mysubclass.data)

if __name__=='__main__':
    main()

Output:

mynewdata

Am I misusing the @property decorator here or am I missing something else in my implementation? Is the @property decorator meant to be used in that kind of scenario?

I am currently using Python 3.10.9