ENGIE1006- project 2 Solved

Intro to Computing for Engineers & Applied Scientists

You are welcome to discuss the problems with other students but the code you submit for take-home projects must be your own work. Please review the academic honesty policy for this course.

Do not use Python modules other than those explicitly mentioned.

Upload the following file to Courseworks:

project2.py

A Dialog System for Ordering Pizza

A dialog system (or conversational agent) is a computer program intended to communicate with humans in natural language, following a specific dialog structure to accomplish a specific tasks. Common examples are automatic phone systems for flight reservations or personal assistants such as Siri and Alexa. In this problem we will use functions to write a very basic dialog system (with limited vocabulary). The system should allow the user to order from an Italian restaurant by asking specific questions.

Here is an example Dialog:

Python: "Hello, would you like pizza or salad?"
User: "pizza"
Python: "Small, medium, or large?"
User: "large"
Python: "Add a topping: pepperoni, mushrooms, spinach, or say 'done'"
User: "mushrooms"
Python: "Add a topping: pepperoni, mushrooms, spinach, or say 'done'"
User: "spinach"
Python: "Add a topping: pepperoni, mushrooms, spinach, or say 'done'"
User: "done"
Python: "You ordered a large pizza with mushrooms and spinach. Place another order or say 'done'.

Python: "Hello, would you like pizza or salad?"
User: "salad"
Python: "Would you like a garden salad or greek salad"
User: "greek"
Python: "please choose a dressing: vinaigrette, ranch, blue cheese, lemon"
User: "blue cheese"
Python: "You ordered a large pizza with mushrooms and spinach and a greek salad with blue cheese dressing. Place another order or say 'done'.               

Python: "Hello, would you like pizza or salad?"
User: "done"

Python: "Your order has been placed. Goodbye."

Implement functions to prompt the user, as illustrated in the diagram below. For example, the salad() function should ask the user for a type of salad. Then the salad() functions calls the dressing() method to asks for a dressing.

All functions return a string, so that you can assemble the order as a string in the calling function. The dressing() function would return the type of dressing, for example "blue cheese". The salad() function would combine the dressing and the salad type into "greek salad with lemon dressing". Finally, the select_meal() function would assemble the complete order in a string.

Note that the functions do not have any parameters. Instead, they should all read user input and then return that input formatted as a string or a list.

The following diagram illustrates the order in which the functions should be called and how the result string should be assembled from the return values step-by-step.

Some complications:

• The toppings() function should ask for toppings repeatedly until the user types "done". The
  return value of the toppings method should be a single string including the toppings, for example
  "pepperoni and mushrooms and spinach".
• The select_meal function should ask the user repeatedly to add an item until the user types "done".
  It should assemble a string representing the complete order.  

Hints:

• None of the functions take any parameters. The important part in this problem is that you are calling
  functions from within other functions ("nested" function calls).
• Use string formatting with {} place holders to assemble the strings. Make sure to write all functions
  specified in the diagram, and only those functions with the specified behavior. 

Write all your functions in a file project2.py. On the top level of project2.py (no indentation), simply call

select_meal()

to start the dialog system.