Instance Method in Python

Syntax of instance method in Python

Python, renowned for its simplicity and clarity, provides developers with an excellent object-oriented framework. In this post, we will look at the syntax and arguments of instance methods in Python, giving light on the fundamental building blocks of object-oriented programming.

Instance methods are functions that are tied to an object and can perform operations on its data. The syntax for creating an instance method is basic. Consider the following example.

Here, my_instance_method is an instance method of the class MyClass. The self argument refers to the instance itself and is a Python convention. It enables the method to read and alter the object's attributes.

Parameters of instance method in Python

Instance methods can accept multiple parameters, enabling them to receive and process data. Let's delve into the anatomy of instance method parameters:

In this example, the display_info method takes an additional parameter year along with the mandatory self. When calling this method, you would pass the year argument explicitly, like so:

The self parameter is implicitly passed, pointing to the instance my_car.

Examples of instance method in Python

The use of self is a key component of instance methods. It refers to the instance that invokes the method and provides access to its properties. When invoking an instance method, Python automatically passes self, establishing a critical connection between the method and the instance.

Python program to demonstrate instance methods

Consider a class named Let's start with a basic yet illustrative Python program that demonstrates the use of instance methods.Person with attributes like name and age. The instance method introduce is defined as printing a personalized introduction for each person.

In this example, the introduce method is called on each instance, which results in customized introductions based on the instance variables' values.

Modifying Instance Variables Inside an Instance Method

Instance methods not only offer access to instance variables but also the ability to alter them. Let's add a function to our Person class that increases a person's age.

Here, the celebrate_birthday method increments the age of the person by 1 and prints a birthday message.

Creating Instance Variables Within an Instance Method

Instance methods also allow us to generate new instance variables dynamically. Consider the following scenario: We wish to track the number of greetings a person gets.

In this example, the greet method dynamically adds and increments the greetings_count instance variable.

Dynamically Adding and Deleting Instance Method to an Object

Python's dynamic nature allows developers to add and delete instance methods on as per their convenience. This can be handy in situations where the behaviour of an object needs to evolve dynamically.

In this example, we dynamically add and then delete the greet method from the Dog instance.

To summarise, understanding Python instance methods provides a world of options for writing dynamic and adaptable programming. Whether you're changing instance variables, adding new ones, or dynamically changing methods, instance methods play an important part in influencing the behaviour of your Python objects.