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Python Object-Oriented Programming

Python Object-Oriented Programming

Python Object-Oriented Programming

In this tutorial, you’ll find out about Object-Oriented Programming (OOP) in Python and its fundamental concept with the help of examples.

Object-Oriented Programming

Python is a multi-worldview programming language. It underpins diverse programming draws near.

One of the popular approaches to solve a programming issue is by making objects. This is known as Object-Oriented Programming (OOP).

An object has two characteristics:

• attributes

• behavior

Let’s take an example:

A parrot is can be an object, as it has the following properties:

• name, age, color as properties

The concept of OOP in Python centers around making reusable code. This idea is otherwise called DRY (Don’t Repeat Yourself).

In Python, the idea of OOP follows some fundamental principles:


A class is a blueprint for the object.

We can think of the class as a sketch of a parrot with labels. It contains all the details about the name, colors, size, etc. Based on these descriptions, we can study about the parrot. Here, a parrot is an object.

The example of a class of parrot can be :

class Parrot:

Here, we use the class keyword to define an empty class Parrot. From class, we construct instances. An instance is a specific object created from a particular class.


An object (example) is an instantiation of a class. At the point when class is characterized, just the depiction of the item is characterized. In this manner, no memory or capacity is designated.

The example for the object of parrot class can be:

obj = Parrot()

Here, obj is an object of class Parrot.

Suppose we have details of parrots. Now, we are going to show how to build the class and objects of parrots.

Example 1: Creating Class and Object in Python

class Parrot:

    # class attribute
    species = "bird"

    # instance attribute
    def __init__(self, name, age): = name
        self.age = age

# instantiate the Parrot class
blu = Parrot("Blu", 10)
woo = Parrot("Woo", 15)

# access the class attributes
print("Blu is a {}".format(blu.__class__.species))
print("Woo is also a {}".format(woo.__class__.species))

# access the instance attributes
print("{} is {} years old".format(, blu.age))
print("{} is {} years old".format(, woo.age))


Blu is a bird
Woo is also a bird
Blu is 10 years old
Woo is 15 years old

In the above program, we created a class with the name Parrot. Then, we define attributes. The attributes are a characteristic of an object.

These attributes are defined inside the __init__ method of the class. It is the initializer method that is first run as soon as the object is created.

Then, we create instances of the Parrot class. Here, blu and woo are references (value) to our new objects.

We can access the class attribute using __class__.species. Class attributes are the same for all instances of a class. Similarly, we access the instance attributes using and blu.age. However, instance attributes are different for every instance of a class.

To learn more about classes and objects, go to Python Classes and Objects


Methods are functions defined inside the body of a class. They are used to characterize the behaviors of an object.

Example 2: Creating Methods in Python

class Parrot:
    # instance attributes
    def __init__(self, name, age): = name
        self.age = age
    # instance method
    def python(self, programming):
        return "{} python {}".format(, programming)

    def online class(self):
        return "{} is now online classes".format(

# instantiate the object
blu = Parrot("Blu", 10)

# call our instance methods
print( class())
Blu python 'Happy'
Blu is now online classes


Inheritance is a method of making another class for using details of a current class without changing it. The newly formed class is an inferred class (or kid class). Similarly, the existing class is a base class (or parent class).

Example 3: Use of Inheritance in Python

# parent class
class Bird:
    def __init__(self):
        print("Bird is ready")

    def whoisThis(self):

    def swim(self):
        print("Swim faster")

# child class
class Penguin(Bird):

    def __init__(self):
        # call super() function
        print("Penguin is ready")

    def whoisThis(self):

    def run(self):
        print("Run faster")

peggy = Penguin()


Bird is ready
Penguin is ready
Swim faster
Run faster

In the above program, we made two classes for example bird (parent class) and Penguin (kid class). The youngster class acquires the elements of the parent class. We can see this from the swim() method.

Once more, the youngster class adjusted the conduct of the parent class. We can see this from the whoisThis() method. Moreover, we broaden the elements of the parent class, by making another run() strategy.

Moreover, we use the super() work inside the __init__() method. This permits us to run the __init__() method for the parent class inside the child class.


Using OOP in Python, we can restrict access to methods and variables. This prevents data from direct modification which is called encapsulation. In Python, we denote private attributes using an underscore as the prefix i.e single _ or double __.

Example 4: Data Encapsulation in Python

class Computer:

    def __init__(self):
        self.__maxprice = 900

    def sell(self):
        print("Selling Price: {}".format(self.__maxprice))

    def setMaxPrice(self, price):
        self.__maxprice = price

c = Computer()

# change the price
c.__maxprice = 1000

# using setter function
Selling Price: 900
Selling Price: 900
Selling Price: 1000

In the above program, we defined a Computer class.

We used __init__() method to store the maximum selling price of the Computer. We tried to modify the price. However, we can’t change it because Python treats the __maxprice as private attributes.

As shown, to change the value, we have to use a setter function i.e setMaxPrice() which takes price as a parameter.


Polymorphism is an ability (in OOP) to use a common interface for different structures (data types).

Suppose, we need to color shape, there are multiple shape options (rectangle, square, circle). However, we could use the same method to color any shape. This concept is called Polymorphism.

Example 5: Using Polymorphism in Python

class Parrot:

    def fly(self):
        print("Parrot can fly")
    def swim(self):
        print("Parrot can't swim")

class Penguin:

    def fly(self):
        print("Penguin can't fly")
    def swim(self):
        print("Penguin can swim")

# common interface
def flying_test(bird):

#instantiate objects
blu = Parrot()
peggy = Penguin()

# passing the object


Parrot can fly
Penguin can't fly

In the above program, we defined two classes Parrot and Penguin. Each of them has a common fly() method. However, their functions are different.

To use polymorphism, we created a common interface i.e flying_test() function that takes an object and calls the object’s fly() method. Thus, when we passed the blu and Peggy objects in the flying_test() function, it ran effectively.

Key Points to Remember:

Object-Oriented Programming makes the program easy to understand as well as efficient.
Since the class is sharable, the code can be reused.
Data is safe and secure with data abstraction.
Polymorphism allows the same interface for different objects, so programmers can write efficient code.

Please feel free to give your comment if you face any difficulty here.

For more Articles click on the below link.

salman khan

Written by worldofitech

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