Python OOP object oriented programming Example code

Python OOP object oriented programming Example code

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#OOP object oriented programming #class keyword class First:    pass fr = First() print type(fr) print type(First) #--------------------------------------------------------------------- class Cat:    def __init__(self, name):       self.name = name missy = Cat('Missy') lucky = Cat('Lucky') print missy.name # Missy print lucky.name # Lucky #--------------------------------------------------------------------- class Cat:    species = 'mammal'    def __init__(self, name, age):       self.name = name       self.age = age missy = Cat('Missy', 3) lucky = Cat('Lucky', 5) print missy.name, missy.age # Missy 3 print lucky.name, lucky.age # Lucky 5 print Cat.species # mammal print missy.__class__.species # mammal print lucky.__class__.species # mammal #--------------------------------------------------------------------- #Methods #Methods are functions defined inside the body of a class class Circle:    pi = 3.141592    def __init__(self, radius=1):       self.radius = radius    def area(self):       return self.radius * self.radius * Circle.pi    def setRadius(self, radius):       self.radius = radius    def getRadius(self):       return self.radius c = Circle() c.setRadius(5) print c.getRadius() # 5 print c.area() # 78.5398 #--------------------------------------------------------------------- class Methods:    def __init__(self):       self.name = 'Methods'    def getName(self):       return self.name m = Methods() print m.getName() # Methods print Methods.getName(m) # Methods #--------------------------------------------------------------------- #Inheritance #inheritance is a way to form new classes using classes that have already been defined class Animal:    def __init__(self):       print "Animal created"    def whoAmI(self):       print "Animal"    def eat(self):       print "Eating" class Dog(Animal):    def __init__(self):       Animal.__init__(self)       print "Dog created"    def whoAmI(self):       print "Dog"    def bark(self):       print "Woof!" d = Dog() d.whoAmI() d.eat() d.bark() #--------------------------------------------------------------------- class Animal:    def __init__(self, name=''):       self.name = name    def talk(self):       pass class Cat(Animal):    def talk(self):       print "Meow!" class Dog(Animal):    def talk(self):       print "Woof!" a = Animal() a.talk() c = Cat("Missy") c.talk() d = Dog("Rocky") d.talk() # Meow! Woof! #--------------------------------------------------------------------- #Special Methods name class Book:    def __init__(self, title, author, pages):       print "A book is created"       self.title = title       self.author = author       self.pages = pages    def __str__(self):       return "Title:%s , author:%s, pages:%s " % \               (self.title, self.author, self.pages)    def __len__(self):       return self.pages    def __del__(self):       print "A book is destroyed" book = Book("Inside Steve's Brain", "Leander Kahney", 304) print book print len(book) del book