Python Classes and Objects for Beginners: OOP Basics with Simple Examples

P11.4 Python Inheritance Basics with an Example

By Ravindra Bagale, trainer LinkedIn Last updated: 27 October 2026

In short: Inheritance lets you reuse the account code and add only the new part.

Why. A savings account is an account plus interest. Inheritance lets you reuse the account code and add only the new part.

What. class Child(Parent): gets all the parent's attributes and methods. super().__init__(...) runs the parent's setup.

How.

Extend a class

Write class New(Old):.
In __init__, call super().__init__(...).
Add new attributes and methods.

Worked example A — A savings account.

Step 1 — What we do. Savings accounts at a bank in Dublin earn interest.

Step 2 — Type and run this code.

class Account:
    def __init__(self, holder, balance=0):
        self.holder = holder
        self.balance = balance
    def deposit(self, amount):
        self.balance += amount

class Savings(Account):
    def __init__(self, holder, balance=0, rate=0.03):
        super().__init__(holder, balance)
        self.rate = rate
    def add_interest(self):
        self.balance += self.balance * self.rate

s = Savings("Niamh", 1000)
s.deposit(500)
s.add_interest()
print(s.balance)

Step 3 — Output you should see.

1545.0

Step 4 — What it means. deposit came from Account for free. Only add_interest is new. 1500 × 1.03 = €1545.

Python next to other languages — define a class. You do not need to learn these other languages. This only shows why Python is easier to read.

Language	Code
Python	`class Account: def __init__(self, holder): ...`
Java	`class Account { Account(String holder) { ... } }`
JavaScript	`class Account { constructor(holder) { ... } }`
Go	`type Account struct { Holder string } (no classes, uses structs)`

Ravindra Bagale's Tip

For data work, you will mostly use classes others wrote (DataFrame, Series). Knowing the basics is enough — do not over-engineer.

Samajla ka? If yes, take the quiz for this chapter. If not, run every example again and change one value each time.