Practice: DogPack#

Download starter code

This practice problem has two parts. The first modifies the Dog class we worked on in the lesson last time and the second writes a new class called DogPack that stores multiple Dog s.

All the files have been included in the provided starter code. To run the program run python main.py in the terminal.

Problem 0: Modify Dog#

In the module dog.py we have the same Dog class that we defined last time. Rename the name field to make it private! Since you are changing the name of the field, you will need to change how it’s accessed in all methods!

After fixing this, you should pass the test labelled “Problem 0”.

Problem 1: Write DogPack#

In the module dog_pack.py write a class called DogPack . The DogPack should have a field called dogs (remember to make it private though) that will be of type list . The DogPack should have the following methods:

  • An initializer that should set up the state of the DogPack . The field for the dogs should start out as the empty list .

    • Hint: Remember the initializer is just like any other method, except that it has a special method name.

  • A method named add_dog that takes a Dog as a parameter and adds it to the end list of Dog s in the DogPack .

  • A method called all_bark that goes to each Dog in the DogPack and has them bark.

For example, after running main.py (command: python main.py ), your program should produce the following output. We first show the relevant part of main for context.

pack = DogPack()
pack.add_dog(Dog('Chester'))
pack.add_dog(Dog('Scout'))
pack.add_dog(Dog('Bella'))
pack.all_bark()

Chester: Woof
Scout: Woof
Bella: Woof

A Note on Testing#

Even though we are asking you to make your fields private, we do a bad thing and access the private fields of your class. This is so we can test your implementation matches our specification. We make this decision for its pedagogical benefit, despite its poor style.

A Note About Naming Convention#

Python uses snake_case for almost everything. All your functions, variables, fields, and even file names should use snake_case . The one major exception is class names which should be CapitalCase (where the first letter of each word is capitalized). This is why we will call the class DogPack but the file name will be dog_pack.py .