Whenever we do object-oriented programming in Python, we mostly come across the __init__ method, which we usually don't fully understand.
Today, programmers are bound to encounter object-oriented programming (OOP) in their careers. As a modern and popular programming language, Python provides all the means to implement the object-oriented philosophy. The __init__ method is the core of object-oriented programming and is one of the basic parts of creating an object.
What is object orientation?
Before studying __init__, let's first understand what is Object-Oriented Programming (OOP), which will be very helpful to understand __init__.
Object-Oriented Programming (OOP) is a programming paradigm that relies on the concept of classes and objects. It is used to structure software programs into simple, reusable pieces of code blueprints (often called classes) that create a single instance of an object.
An object is a complex collection of variables and functions that can be used to represent real entities such as a button, an airplane, or a person.
To declare, initialize, and manipulate objects in Python, we use classes, which are templates for creating objects.
What is the __init__ method?
The __init__ method is an inescapable method in a Python class. It is equivalent to the C++ constructor in the object-oriented approach.
When you create a new object of a class, Python automatically passes your arguments to the __init__ method and calls it to initialize the object's properties.
The __init__ method lets the class initialize the properties of the object, it has no other effect, it is only used in the class.
__init__ usage example
Next, take a look at how to use the __init__ method.
First, we create a Book class, use a simple __init__ method to initialize the Book information, and use a function to print the Book information.
class Book:
def __init__(self, title, author, language):
# Initialize book informations
self.title = title
self.author = author
self.language = language
def print_book_info(self):
print(f'Title: {self.title}')
print(f'Author: {self.author}')
print(f'Language: {self.language}')
Now, we will create an object of a class.
book1 = Book(title='Harry Potter and the Sorcerer Stone', author='JK. Rowling', language='English')
When you create the above object, the __init__ method is called and the Book information is initialized.
To demonstrate this, let's print the Book information.
book1.print_book_info()
Below, take a look at the output:
Title: Harry Potter and the Sorcerer Stone
Author: JK. Rowling
Language: English
As can be seen from the output results, the parameters passed in when we initialized the Book object were initialized and assigned to the corresponding variables.
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