Python Tutorials · Python __init__ Method

Python init Method

Learn all about Python __init__ Method in this comprehensive tutorial.

5 min read advanced

•All classes have a built-in method called __init__(), which is always executed when the class is being initiated.
•Without the __init__() method, you would need to set properties manually for each object:
•You can also set default values for parameters in the __init__() method:
•The __init__() method can have as many parameters as you need:

The init() Method

All classes have a built-in method called __init__(), which is always executed when the class is being initiated.

The __init__() method is used to assign values to object properties, or to perform operations that are necessary when the object is being created.

python

class Person:  def __init__(self, name, age):    self.name = name    self.age = agep1 = Person("Emil", 36)print(p1.name)print(p1.age)

Note: Note: The __init__() method is called automatically every time the class is being used to create a new object.

Why Use init()?

Without the __init__() method, you would need to set properties manually for each object:

python

class Person:  passp1 = Person()p1.name = "Tobias"p1.age = 25print(p1.name)print(p1.age)

Using __init__() makes it easier to create objects with initial values:

python

class Person:  def __init__(self, name, age):    self.name = name    self.age = agep1 = Person("Linus", 28)print(p1.name)print(p1.age)

Default Values in init()

You can also set default values for parameters in the __init__() method:

python

class Person:  def __init__(self, name, age=18):    self.name = name    self.age = agep1 = Person("Emil")p2 = Person("Tobias", 25)print(p1.name, p1.age)print(p2.name, p2.age)

Multiple Parameters

The __init__() method can have as many parameters as you need:

python

class Person:  def __init__(self, name, age, city, country):    self.name = name    self.age = age    self.city = city    self.country = countryp1 = Person("Linus", 30, "Oslo", "Norway")print(p1.name)print(p1.age)print(p1.city)print(p1.country)

Module quiz

2 questions

Which of the following is true about Python __init__ Method?

It is strictly typedIt is evaluated at runtimeIt requires explicit memory managementIt is deprecated

What is the most common pitfall when working with Python __init__ Method?

SyntaxErrorIndentationErrorNameErrorTypeError

Answer all questions to submit.

Python Classes/Objects

Python self Parameter

Python __init__ Method

AI Summary

The __init__() Method

Why Use __init__()?

Default Values in __init__()

Multiple Parameters

Module quiz

Python init Method

The init() Method

Why Use init()?

Default Values in init()