Worksheet 8 - OOP Class Dog example

Here’s an engaging OOP example in Python centered around animals, specifically a Dog class.

Dog Class Example

class Dog:
    def __init__(self, name, breed, age):
        self.name = name       # Name of the dog
        self.breed = breed     # Breed of the dog
        self.age = age         # Age of the dog

    def bark(self):
        return f"{self.name} says Woof!"

    def fetch(self, item):
        return f"{self.name} is fetching the {item}!"

    def introduce(self):
        return f"This is {self.name}, a {self.age}-year-old {self.breed}."

# Creating an instance of the Dog class
my_dog = Dog("Buddy", "Golden Retriever", 3)

# Using the methods
print(my_dog.introduce())  # Output: This is Buddy, a 3-year-old Golden Retriever.
print(my_dog.bark())       # Output: Buddy says Woof!
print(my_dog.fetch("ball"))  # Output: Buddy is fetching the ball!

Explanation:

• Class Definition: The Dog class has an __init__ method that initializes the dog's attributes: name, breed, and age.

• Methods:
  • bark: This method simulates the dog's bark.
  • fetch: This method allows the dog to "fetch" an item specified by the user.
  • introduce: This method provides a friendly introduction of the dog.

Challenge 1: Create Additional Methods

Task: Add sit() and roll_over() methods to the Dog class.

class Dog:
    def __init__(self, name, breed, age):
        self.name = name       # Name of the dog
        self.breed = breed     # Breed of the dog
        self.age = age         # Age of the dog

    def bark(self):
        return f"{self.name} says Woof!"

    def fetch(self, item):
        return f"{self.name} is fetching the {item}!"

    def introduce(self):
        return f"This is {self.name}, a {self.age}-year-old {self.breed}."

    # New method for sitting
    def sit(self):
        return f"{self.name} sits down!"

    # New method for rolling over
    def roll_over(self):
        return f"{self.name} rolls over!"

# Creating an instance of the Dog class
my_dog = Dog("Buddy", "Golden Retriever", 3)

# Using the new methods
print(my_dog.sit())       # Output: Buddy sits down!
print(my_dog.roll_over()) # Output: Buddy rolls over!

Annotations

• The sit() method returns a string indicating that the dog has sat down.
• The roll_over() method returns a string indicating that the dog has rolled over.
• You can test these methods just like the others by calling them on your my_dog instance.

Challenge 2: Expand the Class with a DogPark

Task: Create a DogPark class where multiple dogs can interact.

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

    def bark(self):
        return f"{self.name} says Woof!"

class DogPark:
    def __init__(self):
        self.dogs = []  # List to hold the dogs in the park

    def add_dog(self, dog):
        self.dogs.append(dog)  # Add a dog to the park
        return f"{dog.name} has entered the park!"

    def dog_bark_all(self):
        # Make all dogs bark in the park
        return [dog.bark() for dog in self.dogs]

# Creating instances of the Dog class
dog1 = Dog("Buddy", "Golden Retriever", 3)
dog2 = Dog("Max", "Beagle", 2)

# Creating an instance of DogPark
park = DogPark()

# Adding dogs to the park
print(park.add_dog(dog1))  # Output: Buddy has entered the park!
print(park.add_dog(dog2))  # Output: Max has entered the park!

# Making all dogs bark
barks = park.dog_bark_all()
for bark in barks:
    print(bark)  # Output: Buddy says Woof! and Max says Woof!

Annotations

• The DogPark class has a list called dogs to store the dogs in the park.
• The add_dog() method allows you to add a new dog to the park and returns a message confirming the action.
• The dog_bark_all() method makes all dogs in the park bark and returns their barks as a list.