Phase 3 Code Challenge: Articles - without SQLAlchemy (Updated)

In this code challenge, you will be working with a Magazine domain.

We have three models: Author, Article, and Magazine.

For our purposes, an Author has many Articles, a Magazine has many Articles, and Articles belong to both Author and Magazine.

Author - Magazine is a many to many relationship.

Note: You should draw your domain on paper or on a whiteboard before you start coding. Remember to identify a single source of truth for your data.

Instructions

To get started, run pipenv install while inside of this directory. Then run pipenv shell to jump into the shell.

Build out all of the methods listed in the deliverables. The methods are listed in a suggested order, but you can feel free to tackle the ones you think are easiest. Be careful: some of the later methods rely on earlier ones.

Remember! This code challenge has tests to help you check your work. You can run pytest to make sure your code is functional before submitting.

We've provided you with a tool that you can use to test your code. To use it, run python lib/debug.py from the command line. This will start a ipdb session with your classes defined. You can test out the methods that you write here. You can add code to the lib/debug.py file to define variables and create sample instances of your objects.

Writing error-free code is more important than completing all of the deliverables listed - prioritize writing methods that work over writing more methods that don't work. You should test your code in the console as you write.

Similarly, messy code that works is better than clean code that doesn't. First, prioritize getting things working. Then, if there is time at the end, refactor your code to adhere to best practices. When you encounter duplicated logic, extract it into a shared helper method.

Before you submit! Save and run your code to verify that it works as you expect. If you have any methods that are not working yet, feel free to leave comments describing your progress.

Core Deliverables

Write the following methods in the classes in the files provided. Feel free to build out any helper methods if needed.

Initializers and Properties

Author

• Author __init__(self, name)
  • Author is initialized with a name
• Author property name
  • Returns the author's name
  • Names must be of type str
  • Names must be longer than 0 characters
  • Should not be able to change after the author is instantiated.
  • hint: hasattr()

Magazine

• Magazine __init__(self, name, category)
  • A magazine is initialized with a name and a category
• Magazine property name
  • Returns the magazine's name
  • Names must be of type str
  • Names must be between 2 and 16 characters, inclusive
  • Should be able to change after the magazine is instantiated.
• Magazine property category
  • Returns the magazine's category
  • Categories must be of type str
  • Categories must be longer than 0 characters
  • Should be able to change after the magazine is instantiated.

Article

• Article __init__(self, author, magazine, title)
  • Article is initialized with an Author instance, a Magazine instance, and a title.
• Article property title
  • Returns the article's title
  • Titles must be of type str
  • Titles must be between 5 and 50 characters, inclusive
  • Should not be able to change after the article is instantiated.
  • hint: hasattr()

Object Relationship Methods and Properties

Article

• Article property author
  • Returns the author object for that article
  • Must be of type Author
  • Authors can be changed after the article object is initialized
• Article property magazine
  • Returns the magazine object for that article
  • Must be of type Magazine
  • Magazines can be changed after the article object is initialized

Author

• Author articles()
  • Returns a list of all the articles the author has written
  • Must be of type Article
• Author magazines()
  • Returns a unique list of magazines for which the author has contributed to
  • Must be of type Magazine

Magazine

• Magazine articles()
  • Returns a list of all the articles the magazine has published
  • Must be of type Article
• Magazine contributors()
  • Returns a unique list of authors who have written for this magazine
  • Must be of type Author

Aggregate and Association Methods

Author

• Author add_article(magazine, title)
  • Receives a Magazine instance, and a title as arguments
  • Creates and returns a new Article instance and associates it with that author, the magazine provided
• Author topic_areas()
  • Returns a unique list of strings with the categories of the magazines the author has contributed to
  • Returns None if the author has no articles

Magazine

• Magazine article_titles()
  • Returns a list of the titles strings of all articles written for that magazine
  • Returns None if the magazine has no articles
• Magazine contributing_authors()
  • Returns a list of authors who have written more than 2 articles for the magazine
  • Authors must be of type Author
  • Returns None if the magazine has no authors with more than 2 publications

Advanced Deliverables

These deliverables are not required to pass the code challenge, but if you have the extra time, or even after the code challenge, they are a great way to stretch your skills.

Bonus: Aggregate and Association Method

• Magazine classmethod top_publisher()
  • Returns the Magazine instance with the most articles
  • Returns None if there are no articles.
  • Uncomment lines 206-224 in the magazine_test file
  • hint: will need a way to remember all magazine objects

Bonus: For any invalid inputs raise an Exception

• First, comment out the following lines
  • article_test.py
    • lines 28-29
  • author_test.py
    • lines 31-32, and 35-36
  • magazine_test.py
    • lines 31-32, 47-48, 51-52, 84-85, and 100-102
• Then, uncomment the following lines in the test files
  • article_test.py
    • lines 34-35, 46-47, and 50-51
  • author_test.py
    • lines 39-40, and 53-54
  • magazine_test.py
    • lines 35-36, 55-56, 59-60, 90-91, and 105-106