class Point:
    def __init__(self, x=0, y=0):
        self.set(x, y)

    def set(self, x=0, y=0):
        self.x = x
        self.y = y

    def get(self):
        return (self.x, self.y)

q = Point(15, 20)
x, y = q.get()
q.set(x - 5, y)