class LoggingDict(dict):
    def __setitem__(self, key, value):
        print('Setting %r to %r' % (key, value))
        super().__setitem__(key, value)

my_dict = LoggingDict({"city": "London"})
print (my_dict)
my_dict["postcode"]= "SE10"
print (my_dict)


# Single and Multilevel Inheritance
class Rectangle:
    def __init__(self, length, width):
        self.length = length
        self.width = width

    def area(self):
        return self.length * self.width

    def perimeter(self):
        return 2 * self.length + 2 * self.width

# Here we declare that the Square class inherits from the Rectangle class
class Square(Rectangle):
    def __init__(self, length):
        super().__init__(length, length)


square = Square(4)
print(square.area())

class Square(Rectangle):
    def __init__(self, length):
        super().__init__(length, length)

class Cube(Square):
    def surface_area(self):
        face_area = super().area()
        return face_area * 6

    def volume(self):
        face_area = super().area()
        return face_area * self.length

cube = Cube(3)
print (cube.surface_area())
print(cube.volume())

# Example for Multiple Inheritance
# definition of the class starts here
class Person:
    # defining constructor
    def __init__(self, person_name, person_age):
        self.name = person_name
        self.age = person_age

        # defining class methods

    def show_name(self):
        print(self.name)

    def show_age(self):
        print(self.age)

    # defining another class


class Student:  # Person is the
    def __init__(self, student_id):
        self.student_id = student_id

    def get_id(self):
        print(self.student_id)


class Resident(Person, Student):  # extends both Person and Student class
    def __init__(self, name, age, id):
        Person.__init__(self, name, age)
        Student.__init__(self, id)

    # Create an object of the subclass


resident1 = Resident('John', 30, '102')
resident1.show_name()
resident1.get_id()


# Polymorphism examples

class Document:
    def __init__(self, name):
        self.name = name

    def show(self):
        raise NotImplementedError("Subclass must implement abstract method")


class Pdf(Document):
    def show(self):
        return 'Show pdf contents!'


class Word(Document):
    def show(self):
        return 'Show word contents!'


documents = [Pdf('Document1'), Pdf('Document2'), Word('Document3')]

for document in documents:
    print(document.name + ': ' + document.show())

class Animal:
    # Constructor of the class
    def __init__(self, name):
        self.name = name
    # Abstract method, defined by convention only
    def talk(self):
        raise NotImplementedError("Subclass must implement abstract method")

class Cat(Animal):
    def talk(self):
        return 'Meow!'

class Dog(Animal):
    def talk(self):
        return 'Woof! Woof!'

animals = [Cat('Missy'),
           Cat('Grumpy Cat'),
           Dog('Lassie')]

for animal in animals:
    print (animal.name + ': ' + animal.talk())