Class in Python: Functional Block in Python OOP

If you have been learning or working with programming languages in general, you would have heard of this term: object-oriented programming (OOP). Even in Python, object-oriented programming is an important framework. In this framework, an important component is class. Think of a class in Python as a blueprint for creating objects. This lets you organize and manage complex code easily.

As usual at PythonCentral, in this guide, we will take you through the basics, the syntax, features, best practices, and some practical examples. Get. Set. Learn!

What is a Class in Python?

A class is a template for creating objects. It contains the data (attributes) and behaviours (methods) into a single unit. Let us understand classes a little better.

Basic Syntax of a Class

Here is the basic syntax of a class:

class Car:
def __init__(self, brand, model):
self.brand = brand # Attribute
self.model = model # Attribute

def drive(self):
return f"The {self.brand} {self.model} is driving."

In this script, "Car" is a class with:

__init__ method: A special method that initializes object attributes.
Attributes (brand, model): Variables associated with an instance.
Method (drive): A function inside the class.

How to Create and Use Objects

To create an object (an instance of a class), use a script like this:

my_car = Car("BMW", "X1")
print(my_car.drive()) # Output: The BMW X1 is driving.

Class vs. Instance Variables

Python classes can have instance variables that are unique to each object and class variables that are shared across all instances.

class Dog:
species = "Canis familiaris" # Class variable

def __init__(self, name):
self.name = name # Instance variable

dog1 = Dog("Buddy")
dog2 = Dog("Charlie")
print(dog1.species) # Output: Canis familiaris
print(dog2.species) # Output: Canis familiaris
print(dog1.name) # Output: Buddy
print(dog2.name) # Output: Charlie

What is Inheritance in Python Classes

Inheritance allows a class to inherit attributes and methods from another class.

class Animal:
def make_sound(self):
return "Some generic sound"

class Cat(Animal):
def make_sound(self):
return "Meow"

tom = Cat()
print(tom.make_sound()) # Output: Meow

What are Encapsulation and Private Variables

Encapsulation is the process by which you restrict direct access to some data inside a class. Let us take a example of something sensitive, like a bank account.

class BankAccount:
def __init__(self, balance):
self.__balance = balance # Private variable

def get_balance(self):
return self.__balance

account = BankAccount(1000)
print(account.get_balance()) # Output: 1000

What is Polymorphism in Python

Polymorphism allows different classes to implement the same method in different ways.

class Bird:
def speak(self):
return "Chirp"

class Dog:
def speak(self):
return "Bark"

animals = [Bird(), Dog()]
for animal in animals:
print(animal.speak())

Some Best Practices for Using Classes in Python

Use meaningful class and method names.
Follow the PEP 8 style guide.
Use class methods and static methods when appropriate.
Keep methods small and focused on a single responsibility.

Wrapping Up

Python classes give you a powerful way to structure and manage code. Though class attributes, inheritance, encapsulation, and polymorphism are not the basics, we have included them so that this article becomes your one-stop-shop for learning everything about Python classes. With classes, you can write more efficient and maintainable Python applications.

Start scripting meaningful code with Python classes, design scalable, reusable, and maintainable software solutions with ease. Have a great day ahead!