FutureMind Academy

Last Updated on November 3, 2025 by Rajeev Bagra

When learning object-oriented programming (OOP) in Python, you’ll encounter three types of methods: instance methods, class methods, and static methods.

At first glance, they look quite similar — all are defined inside a class. But each serves a very different purpose depending on what kind of data or behavior it’s meant to handle.

Let’s break this down using a simple, real-world analogy: a company and its employees.

Meet “Techify Solutions Pvt. Ltd.”

Imagine a company called Techify Solutions.
This company has:

• Many employees (each represented by an instance of a class).
• Some company-wide policies (that apply to everyone — defined at the class level).
• A few general utilities (like a calculator — unrelated to any specific employee or policy).

Let’s see how these map to Python’s method types.

1. Instance Methods — Actions of an Employee

An instance method works with the data that belongs to a particular object.
In our analogy, this is like an individual employee doing something — for example, getting a raise.

class Employee:     def __init__(self, name, salary):         self.name = name         self.salary = salary      def give_raise(self, percent):  # instance method         self.salary += self.salary * percent         print(f"{self.name} got a raise! New salary: {self.salary}") 

Analogy:
Rajeev, one of the employees, gets a personal raise.
This change affects only his salary, not anyone else’s.

Key idea:

• Works on instance-level data (self)
• Accesses and modifies object attributes

Usage:

rajeeve = Employee("Rajeev", 50000) rajeeve.give_raise(0.10)  # Rajeev got a raise! New salary: 55000 

2. Class Methods — Company-Wide Policies

A class method affects the class itself, not any specific employee.
In a business, this is like a new company-wide policy that applies to everyone.

class Employee:     raise_percent = 0.05  # default raise policy      @classmethod     def update_raise_policy(cls, new_rate):  # class method         cls.raise_percent = new_rate         print(f"Company policy updated: {cls.raise_percent*100}% raise for all employees!") 

Analogy:
The HR department decides that everyone will now receive a 10% raise instead of 5%.
This affects all employees equally.

Key idea:

• Works on class-level data (cls)
• Commonly used for factory methods or policy updates

Usage:

Employee.update_raise_policy(0.10) # Company policy updated: 10.0% raise for all employees! 

3. Static Methods — General Utilities

A static method doesn’t depend on any class or instance data.
It’s just a helper function that happens to live inside the class for organizational purposes.

class Employee:     @staticmethod     def calculate_tax(amount):  # static method         return amount * 0.2 

Analogy:
Think of it as a tax calculator tool that anyone can use.
It doesn’t care about the company or the employee’s details — it just calculates tax.

Key idea:

• Takes no self or cls
• Belongs logically to the class but doesn’t interact with it

Usage:

tax = Employee.calculate_tax(60000) print(f"Tax on salary: {tax}")  # Tax on salary: 12000.0 

Bringing It All Together

Here’s a complete class demonstrating all three types of methods side by side:

class Employee:     raise_percent = 0.05  # class variable      def __init__(self, name, salary):         self.name = name         self.salary = salary      # Instance method     def give_raise(self):         self.salary += self.salary * Employee.raise_percent         print(f"{self.name}'s new salary: {self.salary}")      # Class method     @classmethod     def update_raise_policy(cls, new_rate):         cls.raise_percent = new_rate         print(f"Company-wide raise policy updated to {cls.raise_percent*100}%")      # Static method     @staticmethod     def calculate_tax(amount):         return amount * 0.2 

Usage:

# Updating company policy Employee.update_raise_policy(0.10)  # Creating employees rajeeve = Employee("Rajeev", 50000) amrita = Employee("Amrita", 60000)  # Applying raise (instance method) rajeeve.give_raise() amrita.give_raise()  # Using static method print("Tax on 50000:", Employee.calculate_tax(50000)) 

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