In Python, the keyword self is one of the most confusing things for beginners.

You see it inside every method of a class… but you never pass it manually when calling the method.

So, what is self? Why is it required? And how should you use it?

Let’s clear it up with a detailed explanation, step-by-step examples, and analogies.

🧠 What is self?

In Python, self refers to the current object (instance) of the class.

It allows:

• Accessing variables tied to that object
• Calling other methods inside the same object
• Storing unique data per object

🧠 Think of it like:

“self is how your object talks to itself.”

🔧 Syntax: Always the First Parameter

class Person:
    def greet(self):  # ← `self` is required
        print("Hello!")

Even though you don’t pass it explicitly when calling the method…

p = Person()
p.greet()   # self is passed automatically

…Python behind the scenes does this:

Person.greet(p)  # 'p' becomes self

✅ Why Is self Needed?

Let’s add attributes:

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

    def greet(self):
        print(f"Hello, I’m {self.name}")

p1 = Person("Ali")
p2 = Person("Fatima")

p1.greet()  # Hello, I’m Ali
p2.greet()  # Hello, I’m Fatima

self.name allows each object to store its own name.

Without self, every object would be identical which defeats the purpose of OOP.

🧪 Real-Life Analogy

Think of a class as a form, and an object as a filled form.

• self = this specific form
• You write your own name, address, etc. in the form (unique per object)

🚫 Common Mistake: Forgetting self

class Car:
    def drive():   # ❌ Missing self
        print("Driving...")

This will throw an error:

TypeError: drive() takes 0 positional arguments but 1 was given

✅ Fix:

class Car:
    def drive(self):
        print("Driving...")

✅ Best Practices