For this challenge, we'll be working with a Movie Review domain, like Netflix.

We have three models: Viewer, Movie, and Review.

A Movie has many Reviews. A Viewer has many Reviews. A Review belongs to a Viewer and belongs to a Movie.

Viewer - Movie 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.

• Classes and Instances
• Class and Instance Methods
• Variable Scope
• Object Relationships
• lists and list Methods

To get started, run pipenv install while inside of this directory.

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 is test-driven. You can run pytest at any time to check your work. You'll need to create your own sample instances so that you can try out your code on your own. Make sure your relationships and methods work in the console before submitting.

We've provided you with a tool that you can use to test your code. To use it, run python 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 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.

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

• Movie __init__(self, title)
  • Movie is initialized with a title (string).
  • Title can be changed after the Movie is initialized.
• Movie property title()
  • Returns the Movie's title.
  • Titles must be strings greater than 0 characters.
  • raise Exception if validation fails.
• Movie class attribute all
  • Stores a list of all movies.

• Viewer __init__(self, username)
  • Viewer is initialized with a username (string)
  • Usernames can be changed after the Viewer is initialized
• Viewer property username()
  • Returns the Viewer's username
  • Usernames must be strings between 6 and 16 characters, inclusive
  • raise Exception if validation fails
  • Stretch goal: usernames must be unique
• Viewer class attribute all
  • Stores a list of all viewers.

• Review __init__(self, viewer, movie, rating)
  • Review is initialized with a Viewer instance, a Movie instance, and a rating (number)
• Review property rating()
  • Returns the rating for the Review instance
  • Ratings must be integers between 1 and 5, inclusive
  • raise Exception if validation fails
• Review class attribute all
  • Stores a list of all reviews.

• Review property viewer()
  • Returns the viewer who wrote the review.
  • Viewers must be Viewer instances.
  • raise Exception if validation fails.
• Review property movie()
  • Returns the movie that is being reviewed.
  • Movies must be Movie instances.
  • raise Exception if validation fails.

• Viewer reviews(self)
  • Returns a list of Review instances associated with the Viewer instance.
• Viewer reviewed_movies(self)
  • Returns a list of Movie instances reviewed by the Viewer instance.

• Movie reviews(self)
  • Returns a list of all the Review instances for the Movie.
• Movie reviewers(self)
  • Returns a list of all of the Viewer instances that reviewed the Movie.

• Viewer has_reviewed_movie(self, movie)
  • Returns True if the Viewer has reviewed this Movie (if there is a Review instance that has this Viewer and Movie), returns False otherwise

• Movie average_rating(self)
  • Returns the average of all ratings for the Movie instance
  • To average ratings, add all ratings together and divide by the total number of ratings.
• Movie classmethod highest_rated(cls)
  • Returns the Movie instance with the highest average rating.