The __init__ Method

The __init__ Method

__init__ is a special method that runs automatically when you create an object. It sets up the object's starting state.

What __init__ does

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

p1 = Person("John", 36)
print(p1.name)  # John
print(p1.age)   # 36

The arguments after self are passed when you create the object.

Why self?

self refers to the current object. It lets each object store its own data. Without it, the method couldn't reach the object's attributes.

Not all classes need __init__

class MyClass:
    x = 5

This class has no __init__; its attribute is shared on the class.

Dunder methods

__init__ is a "dunder" (double underscore) method. Python uses these special names for magic behavior.

Object identity

The __str__ dunder controls how an object prints. Without it, printing shows a memory address.

TL;DR

• __init__(self, ...) runs on object creation.
• self refers to the current object.
• Use it to set initial attribute values.
• Dunder methods use double underscores.