Watch Now This tutorial has a related video course created by the Real Python team. Watch it together with the written tutorial to deepen your understanding: Using Python Class Constructors
Class constructors are a fundamental part of object-oriented programming in Python. They allow you to create and properly initialize objects of a given class, making those objects ready to use. Class constructors internally trigger Python’s instantiation process, which runs through two main steps: instance creation and instance initialization.
If you want to dive deeper into how Python internally constructs objects and learn how to customize the process, then this tutorial is for you.
In this tutorial, you’ll:
- Understand Python’s internal instantiation process
- Customize object initialization using
.__init__() - Fine-tune object creation by overriding
.__new__()
With this knowledge, you’ll be able to tweak the creation and initialization of objects in your custom Python classes, which will give you control over the instantiation process at a more advanced level.
To better understand the examples and concepts in this tutorial, you should be familiar with object-oriented programming and special methods in Python.
Free Bonus: Click here to get access to a free Python OOP Cheat Sheet that points you to the best tutorials, videos, and books to learn more about Object-Oriented Programming with Python.
Python’s Class Constructors and the Instantiation Process
Like many other programming languages, Python supports object-oriented programming. At the heart of Python’s object-oriented capabilities, you’ll find the class keyword, which allows you to define custom classes that can have attributes for storing data and methods for providing behaviors.
Once you have a class to work with, then you can start creating new instances or objects of that class, which is an efficient way to reuse functionality in your code.
Creating and initializing objects of a given class is a fundamental step in object-oriented programming. This step is often referred to as object construction or instantiation. The tool responsible for running this instantiation process is commonly known as a class constructor.
Getting to Know Python’s Class Constructors
In Python, to construct an object of a given class, you just need to call the class with appropriate arguments, as you would call any function:
>>> class SomeClass:
... pass