Simply Explaining Method Overriding & Method Overloading in Python

Summary: This blog explains method overloading and method overriding in Python, covering their definitions, implementations, and differences. Examples demonstrate how to use default and variable-length arguments for overloading and how subclasses override superclass methods to customise behaviour.

Introduction

Python is a computer programming language for building websites and software, automating tasks, and conducting data analysis. It is one of the most popular and widely used programming languages today. Python has helped create Netflix’s recommendation algorithm and even software for self-driving cars. 

There are two types of methods in OOP: method overloading and method overriding. Method overloading and method overriding in Python are two distinct ideas, and their applications are practical. The following blog will discuss the methods with examples and how they work while providing knowledge on their critical differences. 

As a general-purpose language, Python is specially designed for various applications, including Data Science, software and web development, automation, etc. Accordingly, Python methods are crucial for Object-Oriented Programming (OOP). 

Method Overloading In Python

Method overloading in Python is a concept that allows a class to have multiple methods with the same name but different parameter lists. Unlike other programming languages like Java, Python does not directly support method overloading, where you can define multiple methods with different parameter lists. 

However, you can achieve method overloading-like behaviour in Python using default or variable-length arguments (*args and **kwargs).

You can create a method that handles multiple parameter lists by using default arguments and providing default values for some parameters. It allows you to call the method with different numbers of arguments, and it will use the default values for any missing ones.

Using variable-length arguments (*args), you can create a method that can accept any number of arguments. It is useful when you want a method to work with a variable number of arguments without explicitly defining them.

Using variable-length keyword arguments (**kwargs), you can create a method accepting keyword arguments. It provides even more flexibility in handling different combinations of parameters.

Method overloading in Python empowers you to create versatile and adaptable methods for various argument scenarios. It significantly promotes code reusability and enhances the flexibility of your classes, making your code more robust and maintainable. 

While Python does not enforce strict method overloading, you can use these flexible argument-handling techniques to achieve similar functionality.

Method Overloading In Python With Example

Method overloading is a feature in programming languages that allows a class to have multiple methods with the same name but different parameter lists. The technique will depend on the number or type of arguments provided during the function call. Here are some examples of method overloading in Python:

Example 1: Overloading methods with different parameter types

Example 2: Overloading methods with different parameter types

Note that method overloading is not directly supported in Python, unlike in some other programming languages like Java. In Python, only the last defined method with the same name will be used, and the previous ones will be overridden. Thus, the above examples will not work as intended in Python.

To achieve method overloading-like behavior in Python, you can use default or variable-length arguments (*args, **kwargs) to handle different parameter lists. Here’s an example using variable-length arguments:

Remember that method overloading is not a strict requirement in Python, as the language relies on duck typing. It allows functions to accept different types of arguments without explicit method overloading. 

However, using *args and **kwargs can give you more flexibility and achieve results similar to method overloading in other languages.

How do you overload a method in Python?

In Python, method overloading is achieved using default or variable-length arguments (*args, **kwargs) to handle different parameter lists. The idea is to define a single method with a generic name that can accept multiple combinations of arguments. 

Then, the appropriate logic inside the method will handle different cases based on the arguments passed. Here’s how you can overload a method in Python:

Example using default arguments:

Example using variable-length arguments:

Example using variable-length keyword arguments:

Using default or variable-length arguments, you can create methods in Python that can handle multiple argument combinations, effectively achieving method overloading-like behaviour.

Method Overriding In Python

Method overriding is a crucial concept in Object-Oriented Programming (OOP). It allows a subclass to provide a specific implementation for a method already defined in its superclass. 

In Python, method overriding is achieved by defining a process in the subclass with the same name and number of parameters as the method in the superclass.

When an object of the subclass calls the overridden method, Python uses the implementation from the subclass instead of the one in the superclass. This enables the subclass to customise the method’s behaviour while preserving the same method signature as the superclass, ensuring a consistent interface across the class hierarchy.

Method overriding promotes code reuse and flexibility in OOP. It allows you to create specialised versions of methods in subclasses, tailoring their functionality to suit the specific needs of each subclass. 

This behaviour is essential in building scalable and maintainable applications. It enables you to extend existing classes’ behaviour without modifying their source code. It is a powerful tool in Python, facilitating the creation of robust and modular object-oriented systems.

Method Overriding In Python With Example

Method overriding is a concept in object-oriented programming where a subclass provides a specific implementation for a method already defined in its superclass. This allows the subclass to customise the behaviour of the method while maintaining the same method signature. Here’s an example of method overriding in Python:

In this example, we have a superclass Animal with a method make_sound(), which returns a generic sound. The subclasses Dog and Cat extend the Animal class and override the make_sound() method with their specific implementations. 

When we call make_sound() on instances of the subclasses, Python will use the overridden methods defined in the subclass instead of the one in the superclass.

It’s essential to note that method overriding is possible when there is an inheritance relationship between classes (i.e., the subclass extends the superclass). If there is no inheritance, method overriding does not occur, and Python will call the method defined in the class where the function overriding in Python call is made.

Here’s an example to demonstrate this:

In this example, class C extends both classes A and B. When we call foo() on an instance of C, Python will use the foo() method from class A (the first class in the list of base classes). If class C only extended class B, the output would have been “Class B”.

Method overriding is a powerful mechanism for customising and extending the behaviour of classes in object-oriented programming. It allows you to provide specialised implementations in subclasses while maintaining a consistent interface through the superclass.

How To Do Method Overriding In Python?

Method overriding is a concept in Object-Oriented Programming (OOP) where a subclass provides a specific implementation for a method already defined in its superclass. When an object of the subclass calls the overridden method, Python will use the implementation from the subclass instead of the one in the superclass.

Method overriding is based on inheritance, which is one of the critical features of OOP. Inheritance allows a class (subclass) to inherit properties and behaviors from another class (superclass). The subclass can then extend or modify the functionality of the superclass to create a more specialised version of the class.

Here’s a step-by-step explanation of how to override a method in Python:

Superclass and Subclass Relationship:

• In Python, we define classes using the class keyword. The class being inherited is called the superclass (or parent class), and the class inheriting from the superclass is called the subclass (or child class).
• To create a subclass, include the superclass’s name inside parentheses after the subclass name, like this: class SubclassName(SuperclassName):
  

Method Definition in Superclass:

• The superclass contains a method that you want to override in the subclass.
• The method in the superclass must have the same name as the method you want to override in the subclass. This is essential for method overriding to work.
• The method in the superclass can have any implementation you want to share among its subclasses.

Method Definition in Subclass:

• In the subclass, define a method with the same name and number of parameters as the method you want to override in the superclass.
• The method definition in the subclass will replace the implementation of the method in the superclass. This means when you call the method on an instance of the subclass, Python will use the overridden method from the subclass, not the one from the superclass.

Calling the Overridden Method:

• When you create an instance of the subclass and call the method, Python first looks for the process in the subclass.
• If Python finds the method in the subclass, it executes the overridden method from the subclass.
• If Python does not find the method in the subclass, it looks for the method in the superclass and executes it.

Here’s an example of method overriding:

In this example, Animal is the superclass, and Dog and Cat are subclasses. Both Dog and Cat override the make_sound() method defined in the Animal class with their specific implementations.

Method overriding allows you to create more specialised and flexible classes in your code. It promotes code reuse, as you can define common behaviours in the superclass and customise them in the subclasses. This is one of the powerful tools in OOP that enables you to build complex and scalable applications in Python.

Difference Between method overloading and method overriding in Python 

The table below demonstrates method overloading vs method overriding in Python. Accordingly, the differences between Python overloading and overriding are as follows: 

Frequently Asked Questions

What is method overloading in Python?

In Python, method overloading allows a class to have multiple methods with the same name but different parameter lists. Using default or variable-length arguments (*args, **kwargs) achieves this, enhancing method versatility and adaptability.

How is method overriding implemented in Python?

To achieve method overriding in Python, you define a method in a subclass with the same name and parameters as in its superclass. It allows the subclass to provide specific implementation, customising the method’s behaviour.

Can Python support method overloading natively?

No, Python does not natively support method overloading. Instead, you can use techniques such as default or variable-length arguments (*args, **kwargs) to create methods that handle multiple argument combinations, achieving similar functionality.

Conclusion

In conclusion, understanding the differences between method overloading and method overriding in Python is essential in OOP. While the ideas are easily confused, you need to have a clear understanding of these concepts before you apply them to companies. 

If you want to learn Python programming methods, you can significantly opt for online Data Science Courses or Data Science Bootcamps. Pickl.AI ensures you develop practical skills through its Python for Data Science and Data Science Job Guarantee Program. 

Moreover, you can go through Python Interview Questions and Answers to ace your interview with complete preparation on the questions you need to understand clearly.