Python @Property and @*.setter

properties.py

# Reference: https://www.programiz.com/python-programming/property

class Dummy():
    def __init__(self):
        self.msg = "oi" # it calls get and setter functions

    @property
    def msg(self):
        print("Getting...")
        return self._msg

    @msg.setter
    def msg(self, val):
        print("Setting...")
        if not hasattr(self, "_msg"):
            self._msg = val
        return self._msg


d = Dummy()
m1 = d.msg
print(m1)
d.msg = "tchau" # won't change attribute because of setter's logic
m2 = d.msg
print(m2)
assert m1 == m2