Many-to-many Object Relationships Lab

Now that we have learned about several types of relationships it's time to build one of our own. In this lab you will be creating a many-to many relationship in python

The Scenario

We are tasked with building a model to aid in building contracts for books with multiple authors. As a part of this model we need to create an Author model, a Book model and a Contract model. Authors can have many books through contracts, and books can have many authors through contacts.

Tools & Resources

• Github Repo
• Python classes

Instructions

Task 1: Define the Problem

Build a model a many to many relationship between Books and Authors:

• Build Book class
• Build Author class
• Build Contract class
• Build connecting methods between all

Task 2: Determine the Design

Book:

• Attributes:
  • title (string)
  • all (array)
• Methods:
  • contracts()
  • authors()

Authors:

• Attributes:
  • name (string)
  • all (array)
• Methods:
  • contracts()
  • books()
  • sign_contracts(book,date,royalties)
  • total_royalties()

Contracts:

• Attributes:
  • author (Author class),
  • book (Book class),
  • date (string),
  • royalties (integer)
  • all (array)
• Methods:
  • contracts_by_date()

Task 3: Develop, Test, and Refine the Code

Step 1: Create feature branch

Step 2: Create Book class

• __init__: title
• Class attributes- all
• Methods:
  • contracts()- This method should return a list of related contracts
  • authors()- This method should return a list of related authors using the Contract class as an intermediary

Step 3: Authors

• __init__: name (string)
• Class attributes- all
• Methods:
  • contracts()- This method should return a list of related contracts
  • books()- This method should return a list of related books using the Contract class as an intermediary
  • sign_contracts(book,date,royalties)- This method should create and return a new Contract object between the author and the specified book with the specified date and royalties
  • total_royalties()- This method should return the total amount of royalties that the author has earned from all of their contracts

Step 4: Contracts

• __init__:
  • author
  • book
  • date
  • royalties
• Class attributes: all
• Properties: All properties should raise an exception if not valid
  • author: Is an instance of Author class
  • book: Is an instance of Book class
  • date: Is an instance of a str
  • royalties: Is an instance of an int
• Class Methods: contracts_by_date()- This method should return all contracts that have the same date as the date passed into the method

Step 6: Push feature branch and open a PR on GitHub

Step 7: Merge to main

Task 4: Document and Maintain

Best Practice documentation steps:

• Add comments to the code to explain purpose and logic, clarifying intent and functionality of your code to other developers.
• Update README text to reflect the functionality of the application following https://makeareadme.com.
  • Add screenshot of completed work included in Markdown in README.
• Delete any stale branches on GitHub
• Remove unnecessary/commented out code
• If needed, update git ignore to remove sensitive data

Important Submission Note

Before you submit your solution, you need to save your progress with git.

• Add your changes to the staging area by executing git add .
• Create a commit by executing git commit -m "Your commit message"
• Push your commits to GitHub by executing git push origin main