OOP_3.py

from abc import ABC, abstractmethod
# inheritance
class Shape(ABC):
    """
    Shape = superclass / abstract class
    """
    # abstract method
    @abstractmethod
    def area(self):
        pass
    @abstractmethod
    def perimeter(self):
        pass
    # overriding and polymorphism
    def toString(self):
        pass

# child
class Square(Shape):
    "sub class"
    def __init__(self, edge):
        self.__edge = edge # encapsulation private attribute

    def area(self):
        result = self.__edge**2
        print("Square Area: ", result)

    def perimeter(self):
        result = self.__edge*4
        print("Square Perimeter: ", result)

    # override and polymorphise
    def toString(self):
        print("Square edge: ",self.__edge)

# child
class Cirle(Shape):
    """
    Circle Class
    """
    # constant variable
    PI = 3.14

    def __init__(self, radius):
        self.__radius = radius

    def area(self):
        result = self.PI * self.__radius**2
        print("Circle Area: ", result)

    def perimeter(self):
        result = 2 * self.PI * self.__radius
        print("Circle Perimeter: ", result)

    # override and polymorphise
    def toString(self):
        print("Circle radius: ",self.__radius)

c= Cirle(5)
c.area()
c.perimeter()
c.toString()

s= Square(5)
s.area()
s.perimeter()
s.toString()