# oop/class.init.py
class Rectangle:
    def __init__(self, side_a, side_b):
        self.side_a = side_a
        self.side_b = side_b

    def area(self):
        return self.side_a * self.side_b

r1 = Rectangle(10, 4)
print(r1.side_a, r1.side_b)  # 10 4
print(r1.area())  # 40

r2 = Rectangle(7, 3)
print(r2.area())  # 21


"""
$ python class.init.py
10 4
40
21
"""