Object Relations Code Challenge - Flatflix

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.

Topics

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

Instructions

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 does not have tests. You cannot run pytest. 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 tools/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 tools/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.

Deliverables

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

Initializers, Readers, and Writers

Movie

• Movie __init__(self, title)
  • Movie is initialized with a title (string)
• Movie get_title()
  • returns the Movie's title

Viewer

• Viewer __init__(self, username)
  • Viewer is initialized with a username (string)
• Viewer get_username()
  • returns the Viewer's username

Review

• Review __init__(self, viewer, movie, rating)
  • Review is initialized with a Viewer instance, a Movie instance, and a rating (int)
• Review get_rating()
  • returns the rating for the Review instance

Object Relationship Methods

Review

• Review get_viewer()
  • returns the Viewer instance associated with the Review instance
• Review get_movie()
  • returns the Movie instance associated with the Review instance

Viewer

• Viewer get_reviews()
  • returns a list of Review instances associated with the Viewer instance.
• Viewer get_movies()
  • returns a list of Movie instances reviewed by the Viewer instance.
  • HINT: you can get the movies by iterating through the list of reviews

Movie

• Movie get_reviews()
  • returns a list of all the Review instances for the Movie.
• Movie get_viewers()
  • returns a list of all of the Viewer instances that reviewed the Movie.
  • HINT: you can get the viewers by iterating through the list of reviews

Aggregate and Association Methods

Viewer

• Viewer has_reviewed(movie)
  • returns True if the Viewer has reviewed this Movie (if there is a Review instance for this Movie that exists on the Viewer), returns False otherwise
• Viewer rate_movie(movie, rating)
  • a Movie instance and a rating (int) are passed in as arguments
  • this method should create a new Review instance and attach it to the Viewer instance

Movie

• Movie average_rating()
  • 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 highest_review()
  • returns the Review instance with the highest rating.