How to get reference of an inner object in python?

[sun-rs]

#[pyclass]
struct Parent {
    child: Child,
}

#[pymethods]
impl Parent {
    #[new]
    fn new() -> Self {
        Parent {
            child: Child { value: 0 },
        }
    }

    fn set_age_by_parent(&mut self, age: i32) {
        self.child.set_age(age);
    }
}

#[pyclass]
struct Child {
    value: i32,
}

#[pymethods]
impl Child {
    fn set_age(&mut self, age: i32) {
        self.value = age;
    }
}

After wrap these code and generate py module, I could make a new Parent in python and call set_age_by_parent. But if do parent.child.set_age(10), it seems I will get a copy of parent.child. This is not like get a child class from parent class in pure python. Is there any way to do that?

[davidhewitt]

You should write

#[pyclass]
struct Parent {
    child: Py<Child>,
}

i.e. Parent will store a Python reference to a Child object, instead of just the Rust struct.