Conceptos de programación orientada a objetos de Python – Part 1

En Python, la programación orientada a objetos (POO) es un paradigma de programación que utiliza objetos y clases en la programación. Su objetivo es implementar entidades del mundo real como herencia, polimorfismos, encapsulación, etc. en la programación. El concepto principal de los OOP es unir los datos y las funciones que trabajan en eso como una sola unidad para que ninguna otra parte del código pueda acceder a estos datos.

Conceptos principales de la programación orientada a objetos (POO) 

• Clase
• Objetos
• Polimorfismo
• Encapsulación
• Herencia
• Abstracción de datos

Ups 

Clase 

Una clase es una colección de objetos. Una clase contiene los planos o el prototipo a partir del cual se crean los objetos. Es una entidad lógica que contiene algunos atributos y métodos. 

# Python3 program to
# demonstrate defining
# a class
 
class Dog:
    pass

obj = Dog()

class Dog:
 
    # class attribute
    attr1 = "mammal"
 
    # Instance attribute
    def __init__(self, name):
        self.name = name
 
# Driver code
# Object instantiation
Rodger = Dog("Rodger")
Tommy = Dog("Tommy")
 
# Accessing class attributes
print("Rodger is a {}".format(Rodger.__class__.attr1))
print("Tommy is also a {}".format(Tommy.__class__.attr1))
 
# Accessing instance attributes
print("My name is {}".format(Rodger.name))
print("My name is {}".format(Tommy.name))

class Dog:
 
    # class attribute
    attr1 = "mammal"
 
    # Instance attribute
    def __init__(self, name):
        self.name = name
         
    def speak(self):
        print("My name is {}".format(self.name))
 
# Driver code
# Object instantiation
Rodger = Dog("Rodger")
Tommy = Dog("Tommy")
 
# Accessing class methods
Rodger.speak()
Tommy.speak()

# Python code to demonstrate how parent constructors
# are called.
 
# parent class
class Person(object):
 
    # __init__ is known as the constructor
    def __init__(self, name, idnumber):
        self.name = name
        self.idnumber = idnumber
 
    def display(self):
        print(self.name)
        print(self.idnumber)
         
    def details(self):
        print("My name is {}".format(self.name))
        print("IdNumber: {}".format(self.idnumber))
     
# child class
class Employee(Person):
    def __init__(self, name, idnumber, salary, post):
        self.salary = salary
        self.post = post
 
        # invoking the __init__ of the parent class
        Person.__init__(self, name, idnumber)
         
    def details(self):
        print("My name is {}".format(self.name))
        print("IdNumber: {}".format(self.idnumber))
        print("Post: {}".format(self.post))
 
 
# creation of an object variable or an instance
a = Employee('Rahul', 886012, 200000, "Intern")
 
# calling a function of the class Person using
# its instance
a.display()
a.details()

class Bird:
   
    def intro(self):
        print("There are many types of birds.")
 
    def flight(self):
        print("Most of the birds can fly but some cannot.")
 
class sparrow(Bird):
   
    def flight(self):
        print("Sparrows can fly.")
 
class ostrich(Bird):
 
    def flight(self):
        print("Ostriches cannot fly.")
 
obj_bird = Bird()
obj_spr = sparrow()
obj_ost = ostrich()
 
obj_bird.intro()
obj_bird.flight()
 
obj_spr.intro()
obj_spr.flight()
 
obj_ost.intro()
obj_ost.flight()

# Python program to
# demonstrate private members
 
# Creating a Base class
class Base:
    def __init__(self):
        self.a = "GeeksforGeeks"
        self.__c = "GeeksforGeeks"
 
# Creating a derived class
class Derived(Base):
    def __init__(self):
 
        # Calling constructor of
        # Base class
        Base.__init__(self)
        print("Calling private member of base class: ")
        print(self.__c)
 
 
# Driver code
obj1 = Base()
print(obj1.a)
 
# Uncommenting print(obj1.c) will
# raise an AttributeError
 
# Uncommenting obj2 = Derived() will
# also raise an AtrributeError as
# private member of base class
# is called inside derived class