Self reference in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does self mean in a Python class?

self is a way for an object to refer to itself inside its methods. It lets the object access its own attributes and other methods.

beginner

Why do we need to use self in method definitions?

Because Python does not automatically pass the object to methods. self is the first parameter that receives the object when a method is called.

beginner

How do you use self to change an object's attribute inside a method?

You write self.attribute_name = new_value inside the method to update the object's attribute.

intermediate

What happens if you forget to include self as the first parameter in a method?

Python will raise an error because it expects the method to receive the object as the first argument, but it won't get it.

intermediate

Can self be named something else?

Yes, but self is the strong convention in Python. Using other names can confuse readers.

In Python, what does self represent inside a class method?

A The instance of the class calling the method

B A global variable

C A class method decorator

D A local variable inside the method

self always refers to the current object instance inside class methods.

What will happen if you define a method without self as the first parameter and try to call it on an object?

A It will work normally

B Python will raise a TypeError

C The method will be treated as a static method

D The method will ignore the object

Python expects the first parameter to be the instance. Without it, calling the method raises a TypeError.

Which of these is the correct way to set an attribute name inside a method using self?

A self->name = 'Alice'

B name = 'Alice'

C self.name = 'Alice'

D set self.name = 'Alice'

Use self.name = value to set or change an attribute of the object.

Is it mandatory to name the first parameter self in Python class methods?

A Yes, it must be <code>self</code>

B Yes, or the code will not run

C No, you can omit it

D No, but it is strongly recommended

You can use any name, but self is the standard and makes code easier to read.

What is the role of self when calling another method inside the same class?

A You use <code>self.method_name()</code> to call it on the same object

B You call methods directly by name without <code>self</code>

C It is not needed to call other methods

D You must import the method first

Use self.method_name() to call another method on the same object.

Explain what self means in Python classes and why it is important.

Think about how an object talks about itself inside its own methods.

Describe how you would use self to change an attribute inside a class method.

Imagine you want to update a property of your own object.