Instance method in Python

An instance method is a function defined inside a class that operates on the instance (object) of that class. By default, it takes self as the first parameter, which refers to the current object (instance) of the class, allowing it to access and modify instance variables (object’s data) and call other methods of that object.

Syntax

class ClassName:
    def instance_method(self, parameters):
        # code here
        # we can access instance variables using self.variable_name

Example: Simple Instance Method.

Python

class Student:
    def __init__(self, name, age):
        # Instance variables
        self.name = name
        self.age = age

    # Instance Method
    def display_info(self):
        # Access instance variables using self
        print(f"Name: {self.name}, Age: {self.age}")

# Create an object (instance) of Student
student1 = Student("Ashish", 29)

# Call instance method
student1.display_info()

Output: Name: Ashish, Age: 29

Example: Simple Instance Method.

Python

class BankAccount:
    def __init__(self, account_holder, balance=0):
        self.account_holder = account_holder
        self.balance = balance

    # Instance method to deposit money
    def deposit(self, amount):
        self.balance += amount
        print(f"{amount} deposited. New Balance: {self.balance}")

    # Instance method to withdraw money
    def withdraw(self, amount):
        if self.balance >= amount:
            self.balance -= amount
            print(f"{amount} withdrawn. Remaining Balance: {self.balance}")
        else:
            print("Insufficient Balance")

# Create object (instance)
account1 = BankAccount("Ashish", 1000)

# Call instance methods
account1.deposit(500)
account1.withdraw(300)
account1.withdraw(2000)  # insufficient balance

Output: 500 deposited. New Balance: 1500
300 withdrawn. Remaining Balance: 1200
Insufficient Balance

Key Points about Instance Methods:

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