Accessing and modifying attributes in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the attribute 'color' of the car object.

Python

print(car.[1])

Drag options to blanks, or click blank then click option'

Ayear

Bspeed

Ccolor

Dmodel

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses like a method call, e.g., car.color()

Trying to access attribute with brackets, e.g., car['color']

The attribute 'color' is accessed using dot notation: car.color.

2fill in blank

medium

Complete the code to change the 'speed' attribute of the car object to 100.

Python

car.[1] = 100

Drag options to blanks, or click blank then click option'

Aspeed

Bcolor

Cmodel

Dyear

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses like a method call, e.g., car.speed() = 100

Trying to assign to a non-existing attribute

To modify an attribute, assign a new value using dot notation: car.speed = 100.

3fill in blank

hard

Fix the error in the code to correctly access the 'model' attribute of the car object.

Python

print(car[1]model)

Drag options to blanks, or click blank then click option'

A["model"]

Bmodel

C->model

D.model

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets like a dictionary: car["model"]

Using arrow notation which is not valid in Python

Attributes are accessed using dot notation: car.model.

4fill in blank

hard

Fill both blanks to create a new attribute 'owner' with value 'Alice' for the car object.

Python

car.[1] = [2]

Drag options to blanks, or click blank then click option'

Aowner

B'Alice'

C'Bob'

Dspeed

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the string value

Using an existing attribute name instead of a new one

To add a new attribute, assign a value using dot notation: car.owner = 'Alice'.

5fill in blank

hard

Fill all three blanks to print the updated 'year' attribute after changing it to 2025.

Python

car.[1] = [2]
print(car.[3])

Drag options to blanks, or click blank then click option'

Ayear

B2025

Dspeed

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the number 2025

Printing a different attribute than the one changed

First, assign the new value to the 'year' attribute, then print it using dot notation.

Practice

1. What is the correct way to access the attribute color of an object car in Python?

easy

A. car.color

B. car[color]

C. car->color

D. car[color()]

Solution

1. Step 1: Understand attribute access syntax

   In Python, attributes of an object are accessed using dot notation: object.attribute.

2. Step 2: Apply to given object and attribute

   For object car and attribute color, the correct syntax is car.color.

3. Final Answer:

   car.color -> Option A

4. Quick Check:

   Dot notation accesses attributes = car.color [OK]

Hint: Use dot (.) to access attributes on objects [OK]

Common Mistakes:

• Using brackets like car[color]
• Using arrow notation like car->color
• Calling attribute as a function like car[color()]

2. Which of the following is the correct syntax to change the attribute age of an object person to 30?

easy

A. person["age"] = 30

B. person.age = 30

C. person->age = 30

D. person.age(30)

Solution

1. Step 1: Recall attribute assignment syntax

   To modify an attribute, use dot notation with assignment: object.attribute = value.

2. Step 2: Apply to given object and attribute

   Set person.age to 30 by writing person.age = 30.

3. Final Answer:

   person.age = 30 -> Option B

4. Quick Check:

   Assign attribute with dot and equals = person.age = 30 [OK]

Hint: Use dot and equals to set attribute: obj.attr = value [OK]

Common Mistakes:

• Using brackets like person["age"] = 30
• Using arrow notation person->age = 30
• Trying to call attribute like a function person.age(30)

3. What will be the output of this code?

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

my_dog = Dog("Buddy")
print(my_dog.name)
my_dog.name = "Max"
print(my_dog.name)

medium

A. Buddy\nBuddy

B. Max\nBuddy

C. Max\nMax

D. Buddy\nMax

Solution

1. Step 1: Understand initial attribute value

   The constructor sets self.name to "Buddy". So, my_dog.name is initially "Buddy".

2. Step 2: Modify attribute and print again

   After printing "Buddy", the code sets my_dog.name = "Max". The second print outputs "Max".

3. Final Answer:

   Buddy Max -> Option D

4. Quick Check:

   Initial then changed attribute prints = Buddy Max [OK]

Hint: Changing attribute updates value printed next [OK]

Common Mistakes:

• Thinking attribute change does not affect output
• Confusing order of prints
• Assuming attribute is immutable

4. Identify the error in this code snippet:

class Cat:
    def __init__(self, color):
        self.color = color

kitty = Cat("black")
print(kitty[color])

medium

A. Using brackets instead of dot to access attribute

B. Missing parentheses in class definition

C. Incorrect constructor name

D. Attribute 'color' not defined

Solution

1. Step 1: Check attribute access syntax

   The code uses kitty[color], which tries to access like a dictionary key, but color is an attribute, not a key.

2. Step 2: Correct syntax for attribute access

   Use dot notation: kitty.color to access the attribute.

3. Final Answer:

   Using brackets instead of dot to access attribute -> Option A

4. Quick Check:

   Attributes use dot, not brackets = Using brackets instead of dot to access attribute [OK]

Hint: Use dot, not brackets, to access attributes [OK]

Common Mistakes:

• Using brackets like kitty[color]
• Thinking attributes are dictionary keys
• Confusing attribute access with indexing

5. Given this class:

class Book:
    def __init__(self, title, author):
        self.title = title
        self.author = author

book1 = Book("1984", "Orwell")
book2 = Book("Animal Farm", "Orwell")

# Change author of book2 to "George Orwell"

Which code correctly updates book2 author without affecting book1?

hard

A. book2["author"] = "George Orwell"

B. Book.author = "George Orwell"

C. book2.author = "George Orwell"

D. book1.author = "George Orwell"

Solution

1. Step 1: Understand instance vs class attributes

   Changing book2.author modifies only that instance's attribute, not book1.

2. Step 2: Avoid changing class attribute or other instance

   Assigning Book.author changes class attribute for all instances; changing book1.author affects wrong object; brackets are invalid syntax.

3. Final Answer:

   book2.author = "George Orwell" -> Option C

4. Quick Check:

   Set instance attribute with dot on correct object = book2.author = "George Orwell" [OK]

Hint: Assign attribute on specific object with dot notation [OK]

Common Mistakes:

• Changing class attribute instead of instance attribute
• Modifying wrong object's attribute
• Using brackets instead of dot notation