setters_vs_functional.py

class A:
    def __init__(self, x):
        self._x = x
    
    @property
    def y(self):
        return self.x * 2
        
    @y.setter
    def y(self, val):
        self.x = val / 2
        
a = A(10)
a.y = 30
a.y * 20
        
    
class B:
    def __init__(self, x):
        self._x = x
        self._y = x * 2
    
    def x(self, val=None):
        if val:
            self._x = val
            self._y = val * 2
        return self._x
    
    def y(self, val=None):
        if val:
            self._y = val
            self._x = val / 2
        return self._y

b = B(10)
b.y(30)
b.y() * 20