# oop/class.self.py
class Square:
    side = 8
    def area(self):  # self is a reference to an instance
        return self.side ** 2

sq = Square()
print(sq.area())  # 64 (side is found on the class)
print(Square.area(sq))  # 64 (equivalent to sq.area())

sq.side = 10
print(sq.area())  # 100 (side is found on the instance)



"""
$ python class.self.py
64
64
100
"""