from functools import cached_property

class Parent:
    @property
    def prop(self) -> int:
        ...

class Child(Parent):
    def __init__(self):
        self._prop = 4

    @cached_property
    def prop(self) -> int:
        print("Calc value ..")
        return self._prop ** 2

c = Child()
print(c.prop)
print(c.prop)  # Returns cached value

c.prop = 24  # Overwrite cached value
print(c.prop)

c.prop = "Hello World"  # incompatiable types
print(c.prop)