Accessing and modifying attributes in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an attribute in a Python class?

An attribute is a variable that belongs to an object or class. It stores information about the object.

beginner

How do you access an attribute of an object in Python?

Use the dot notation: object.attribute. For example, car.color accesses the color attribute of the car object.

beginner

How can you change the value of an attribute in Python?

Assign a new value using dot notation: object.attribute = new_value. This updates the attribute's value.

intermediate

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

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

intermediate

How can you check if an object has a specific attribute before accessing it?

Use the built-in function hasattr(object, 'attribute'). It returns True if the attribute exists, otherwise False.

How do you access the attribute 'age' of an object 'person'?

A person->age

B person['age']

C age.person

D person.age

Use dot notation to access attributes: person.age

What will happen if you try to access a missing attribute in Python?

A Returns None

B Raises AttributeError

C Creates the attribute automatically

D Returns 0

Python raises AttributeError if the attribute does not exist.

Which of these changes the value of an attribute 'color' of object 'car' to 'red'?

A car.color = 'red'

B car['color'] = 'red'

C color.car = 'red'

D setattr(car, 'color')

Assign a new value using dot notation: car.color = 'red'

How can you safely check if 'height' attribute exists in object 'tree'?

A if tree['height']:

B if tree.height:

C if hasattr(tree, 'height'):

D if 'height' in tree:

Use hasattr(object, 'attribute') to check existence safely.

What is the correct way to add a new attribute 'speed' with value 100 to object 'car'?

A car.speed = 100

B car['speed'] = 100

C addattr(car, 'speed', 100)

D car.add('speed', 100)

You add new attributes by assigning them with dot notation.

Explain how to access and modify an attribute of an object in Python.

Think about how you get and set values using the dot.

Describe what happens if you try to access an attribute that does not exist and how to avoid errors.

Consider checking before accessing.