Objective:
- Concept of Polymorphism
Activity:
Task 1:
Create a class named Shape. Also, create classes Circle, Square, Triangle, and Rectangle as subclasses of the Shape class. Each subclass should override a calculate_area method of the Shape class. The initializers of these classes should take their respective dimensions as arguments.
Task 2:
In Python, all methods are virtually inherited by default. This means that if a method is overridden in a derived class, the overridden version of the method is invoked.
Solution:
class Shape:
def __init__(self, color):
self.color = color
def calculate_area(self):
return 0
def __del__(self):
print("~Shape() called.")
class Circle(Shape):
def __init__(self, radius, color):
super().__init__(color)
self.radius = radius
print("Circle constructor invoked.")
def calculate_area(self):
return 3.14 * self.radius * self.radius
def __del__(self):
print("~Circle() called.")
class Square(Shape):
def __init__(self, side, color):
super().__init__(color)
self.side = side
print("Square constructor invoked.")
def calculate_area(self):
return self.side * self.side
def __del__(self):
print("~Square() called.")
class Rectangle(Shape):
def __init__(self, length, width, color):
super().__init__(color)
self.length = length
self.width = width
print("Rectangle constructor invoked.")
def calculate_area(self):
return self.length * self.width
class Triangle(Shape):
def __init__(self, base, height, color):
super().__init__(color)
self.base = base
self.height = height
print("Triangle constructor invoked.")
def calculate_area(self):
return 0.5 * self.base * self.height
def __del__(self):
print("~Triangle() called.")
def main():
t1 = Triangle(1.0, 9.0, "Red")
c1 = Circle(2, "Blue")
r1 = Rectangle(6, 2, "Orange")
print(t1.calculate_area(), t1.color)
print(c1.calculate_area())
print(r1.calculate_area())
sptr1 = t1
sref = r1
print(sptr1.calculate_area(), sptr1.color)
print(sref.color, sref.calculate_area())
s1 = Shape("Purple")
def sum_area(shape1, shape2):
return shape1.calculate_area() + shape2.calculate_area()
print(sum_area(t1, c1))
print(sum_area(s1, r1))
print(sum_area(s1, t1))
main()
