Polymorphism through inheritance in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a method that prints a greeting.

Python

class Animal:
    def speak(self):
        print([1])

pet = Animal()
pet.speak()

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

AHello

B"Hello!"

Cprint("Hello!")

Dreturn "Hello!"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the string.

Using return instead of print.

Trying to print inside the print statement.

The speak method should print the string Hello!. Using quotes around the string is necessary.

2fill in blank

medium

Complete the code to override the speak method in the Dog class.

Python

class Animal:
    def speak(self):
        print("Some sound")

class Dog(Animal):
    def speak(self):
        print([1])

pet = Dog()
pet.speak()

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

Areturn "Woof!"

BWoof!

Cprint("Woof!")

D"Woof!"

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the string.

Using print inside print.

Using return instead of print.

The Dog class overrides speak to print "Woof!". The string must be quoted.

3fill in blank

hard

Fix the error in the code to call the speak method of the Cat class.

Python

class Animal:
    def speak(self):
        print("Some sound")

class Cat(Animal):
    def speak(self):
        print("Meow!")

pet = Cat()
pet.[1]()

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

Aspeak

Bsay

Csound

Dtalk

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names not defined in the class.

Forgetting parentheses when calling the method.

The method to call is speak. Other names do not exist and cause errors.

4fill in blank

hard

Fill both blanks to create a list of animals and call their speak methods.

Python

class Animal:
    def speak(self):
        print("Some sound")

class Bird(Animal):
    def speak(self):
        print("Chirp!")

animals = [[1], [2]]
for pet in animals:
    pet.speak()

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

AAnimal()

BBird()

CDog()

DCat()

Attempts:

3 left

💡 Hint

Common Mistakes

Using class names without parentheses.

Using classes not defined in the code.

The list animals contains an Animal and a Bird instance. Both have a speak method.

5fill in blank

hard

Fill both blanks to create a dictionary mapping animal names to their sounds using polymorphism.

Python

class Animal:
    def speak(self):
        return "Some sound"

class Dog(Animal):
    def speak(self):
        return "Woof!"

class Cat(Animal):
    def speak(self):
        return "Meow!"

pets = [Dog(), Cat()]
sounds = { = {pet.{BLANK_2}}(): pet.{{BLANK_2}}() for pet in pets}

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

A{

Bspeak

D[

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets instead of curly braces for dictionary.

Not calling the method with parentheses.

Using different method names.

The dictionary is created with curly braces {}. The keys and values come from calling speak() on each pet.