Instance attributes in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are instance attributes in Python?

Instance attributes are variables that belong to a specific object created from a class. Each object can have different values for these attributes.

beginner

How do you define an instance attribute inside a class?

You define instance attributes inside the __init__ method using self, like: <br>self.attribute_name = value.

intermediate

What is the difference between instance attributes and class attributes?

Instance attributes belong to each object separately, while class attributes are shared by all objects of the class.

intermediate

Can instance attributes be added outside the __init__ method?

Yes, you can add or change instance attributes anytime using dot notation, like object.attribute = value.

beginner

What happens if you try to access an instance attribute that does not exist?

Python raises an AttributeError because the object does not have that attribute.

Where are instance attributes usually defined in a Python class?

A Inside a static method

B Outside the class

C As global variables

D Inside the __init__ method using self

Instance attributes are typically set inside the __init__ method using self to attach them to the object.

What keyword is used to refer to the current object inside a class?

A self

B this

C me

D obj

In Python, 'self' refers to the current object inside class methods.

If you change an instance attribute on one object, does it affect other objects of the same class?

A Only if the attribute is a class attribute

B Yes, all objects change

C No, only that object changes

D Only if the attribute is private

Instance attributes belong to each object separately, so changing one does not affect others.

What error occurs if you try to access a missing instance attribute?

A AttributeError

B NameError

C TypeError

D ValueError

Accessing a non-existent attribute raises an AttributeError.

Can you add new instance attributes after an object is created?

A No, attributes must be defined in __init__

B Yes, using dot notation on the object

C Only if the class allows it explicitly

D Only for class attributes

Python allows adding new instance attributes anytime using dot notation.

Explain what instance attributes are and how they differ from class attributes.

Think about how each object can have its own data.

Describe how to create and access instance attributes in a Python class.

Remember the role of self inside methods.