Adventures in Machine Learning

Exploring Polymorphism and Overloading Operators in Python

Object-oriented programming is widely used to build software applications for its advantages such as abstraction, encapsulation, inheritance, and polymorphism. Among them, polymorphism is the ability of objects to take multiple forms and execute the same action in different ways.

This article provides a comprehensive understanding of polymorphism and overloading operators in Python.

Polymorphism in Object-Oriented Programming

Polymorphism is a core concept in object-oriented programming that allows the same method to be used across different object types. The idea behind polymorphism is that objects can take on different forms and perform the same operation in different ways.

This means that a method that works for one object can be used for another, regardless of their class type or data type.

Polymorphism with Built-In Function len()

Built-in functions in Python are inherently polymorphic. For example, the len() function, used to count the number of items in a container, can work with multiple object types such as strings and lists.

When called on a string, it returns the number of characters in the string. When called on a list, it returns the number of items in the list.

Polymorphism with Inheritance and Method Overriding

Inheritance is another important feature of object-oriented programming that allows the creation of sub-classes that inherit characteristics from a parent class. Method overriding is the process of creating a new implementation of an existing method in a child class.

This allows the child class to extend the functionality of the parent class or reimplement the method in a customized way.

Advantages of Method Overriding

Method overriding has significant advantages in object-oriented programming. It allows the child class to modify the behavior of the parent class code to suit its particular needs.

Method overriding also allows the child class to add new functionality while keeping the original functionality intact. This means that the parent class code can be reused, reducing the time and effort required for software development.

Polymorphism in Class Methods

Polymorphism can also be implemented in class methods. A class method is a method that is bound to the class and not the object instance.

Class methods can be used to perform actions on objects such as lists or tuples. They can also be used in for loops.

Polymorphism in Function and Objects

Polymorphism in function and objects involves passing the same action to different objects. A function can be designed to take different parameters and perform the same action with each parameter.

This makes it easy to repeat method calls with different objects without having to write separate actions for each object.

Polymorphism in Built-In Methods

Operator overloading in Python involves changing the behavior of the built-in methods such as arithmetic and concatenation. By default, Python only allows certain operators to work with certain data types.

However, by using operator overloading, the functionality of these operators can be extended to new data types. For example, the reversed() function can be used with any object that supports iteration.

Method Overloading

Method overloading involves creating multiple methods with the same name but different parameters. This is not supported in Python, and attempting to do so will result in a TypeError.

However, the desired functionality can be achieved by using default parameter values or a variable argument list.

Overloading Operators in Python

Operator overloading is the process of changing the behavior of an operator such as the + operator and * operator for custom objects. Python allows the overloading of these operators by defining special methods such as __add__() and __mul__().

These methods are known as magic methods because they cannot be called explicitly but are invoked by specific Python operators. Overloading + Operator for Custom Objects

The __add__() method can be used to overload the + operator for custom objects.

This allows custom objects to perform addition operations within the context of their class type. For example, the addition of two employee objects could return the sum of their salaries.

Overloading * Operator

The __mul__() method can be used to overload the * operator for custom objects. This is commonly used to calculate the total cost of an operation by multiplying the hourly rate of an employee by the number of hours worked.

The timesheet object could contain this information.

Magic Methods for Overloading Operators

Magic methods are used to overload operators in Python. They are commonly used to implement mathematical operators, assignment operators, and relational operators.

Some of the commonly used magic methods include __add__(), __sub__(), __mul__(), __truediv__(), __eq__(), and __lt__().


In conclusion, polymorphism and operator overloading are essential concepts in object-oriented programming using Python. Polymorphism enables a single method to be used across different object types.

Operator overloading allows the customization of operators such as + and * for custom objects using magic methods. Understanding these concepts is necessary to improve the efficiency and reusability of software applications.

To summarize, polymorphism and operator overloading are critical concepts in Python programming. Polymorphism enables a single method to work with multiple object types while operator overloading enables the customization of operators for custom objects using magic methods.

Understanding these concepts is essential to enhance software application efficiency and reusability. By using the various techniques in polymorphism and operator overloading, programmers can avoid unnecessary code duplication and minimize errors.

In conclusion, mastering these concepts is crucial for those interested in advancing their Python skills and developing high-quality applications.