Mock Code Challenge - Coffee Shop (Object Relationships)
For this assignment, we'll be working with a Coffee shop-style domain.
We have three models: Coffee, Customer, and Order.
For our purposes, a Coffee has many Orders, a Customer has many
Orders, and a Order belongs to a Customer and to a Coffee.
Coffee - Customer 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 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 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.
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
Customer
Customer __init__(self, name)- Customer should be initialized with a name
Customer property name- Return name
- Names must be of type
str - Names must be between 1 and 15 characters, inclusive
- if you are using exceptions comment out the test on lines 32 - 35 in the customer_test.py and uncomment lines 37 - 45
Coffee
Coffee __init__(self, name)- Coffees should be initialized with a name, as a string
Coffee property name- Returns the coffee's name
- Should not be able to change after the coffee is created
- hint: hasattr()
- if you are using exceptions comment out the test on lines 20 - 24 in the coffee_test.py and uncomment lines 26 - 30
Order
Order __init__(self, customer, coffee, price)- Orders should be initialized with a customer, coffee, and a price (a number)
Order property price- Returns the price for a coffee
- Price must be a number between 1 and 10, inclusive
Object Relationship Methods and Properties
Order
Order property customer- Returns the customer object for that order
- Must be of type
Customer
Order property coffee- Returns the coffee object for that order
- Must be of type
Coffee
Coffee
Coffee orders()- Returns a list of all orders for that coffee
- orders must be of type
Order
Coffee customers()- Returns a unique list of all customers who have ordered a particular coffee.
- Customers must be of type
Customer
Customer
Customer orders()- Returns a list of all orders a customer has ordered
- orders must be of type
Order
Customer coffees()- Returns a unique list of all coffees a customer has ordered
- Coffees must be of type
Coffee
Aggregate and Association Methods
Customer
Customer create_order(coffee, price)- given a coffee object and a price(as an integer), creates a new order and associates it with that customer and coffee.
Coffee
Coffee num_orders()- Returns the total number of times that coffee has been ordered
Coffee average_price()- Returns the average price for a coffee based on its orders
- Reminder: you can calculate the average by adding up all the orders prices and dividing by the number of orders
Bonus: For any invalid inputs raise an Exception.
Uncomment the following lines in the test files:
customer_tests.py
- lines 37 - 45
coffee_tests.py
- lines 26 - 30
order_tests.py
- lines 20 - 30