In this article i am gone to share Coursera Course: Programming in Python by Meta Week 2 | Programming Assignment: Functions, loops and data structures Solution with you..

Programming Assignment: Functions, loops and data structures

Introduction

In this lab you will be presented with a menu ordering system which will allow users to input three choices for a select menu. You are tasked with completing the menu system so that it returns and calculates the final bill for the user.

Objectives

• Create new functions to solve specific problems.
• Gain experience of using for loops to iterate over different data collections.
• Create and use data structures to store, retrieve and loop over data.

Instructions

• Step 1: Open the script ordering_system.py present inside the project folder.
• Step 2: Run the script and, when requested, enter in the three products of your choice based on the menu – 1 = espresso, 2 = coffee etc.
• Step 3: To run the script, open the terminal and execute the command below.
• python3 ordering_system.py

Open the terminal to run the script.

• Step 4: Extend the script to have a new function called calculate_subtotal. It should accept one argument which is the order list and return the sum of the prices of the items in the order list.
• Step 5: Implement calculate_tax() which calculates the tax of the subtotal. The tax percentage is 15% of overall bill.
• Step 6: Implement summarize_order() which returns a list of the names of the items that the customer ordered and the total amount (including tax) that they have to pay. The orders should show the name and price.

Programming Assignment: Functions, loops and data structures Solution

Copy and paste this code..

menu = {
    1: {"name": 'espresso',
        "price": 1.99},
    2: {"name": 'coffee', 
        "price": 2.50},
    3: {"name": 'cake', 
        "price": 2.79},
    4: {"name": 'soup', 
        "price": 4.50},
    5: {"name": 'sandwich',
        "price": 4.99}
}

def calculate_subtotal(order):
    """ Calculates the subtotal of an order

    [IMPLEMENT ME] 
        1. Add up the prices of all the items in the order and return the sum

    Args:
        order: list of dicts that contain an item name and price

    Returns:
        float = The sum of the prices of the items in the order
    """
    print('Calculating bill subtotal...')
    ### WRITE SOLUTION HERE
    subtotal = 0.0
    for item in order:
        item_price = item["price"]
        subtotal += item_price
    return round(subtotal, 2)

def calculate_tax(subtotal):
    """ Calculates the tax of an order

    [IMPLEMENT ME] 
        1. Multiply the subtotal by 15% and return the product rounded to two decimals.

    Args:
        subtotal: the price to get the tax of

    Returns:
        float - The tax required of a given subtotal, which is 15% rounded to two decimals.
    """
    print('Calculating tax from subtotal...')
    ### WRITE SOLUTION HERE
    tax = subtotal * 0.15
    return round(tax, 2)

def summarize_order(order):
    """ Summarizes the order

    [IMPLEMENT ME]
        1. Calculate the total (subtotal + tax) and store it in a variable named total (rounded to two decimals)
        2. Store only the names of all the items in the order in a list called names
        3. Return names and total.

    Args:
        order: list of dicts that contain an item name and price

    Returns:
        tuple of names and total. The return statement should look like 
        
        return names, total

    """
    print_order(order)
    ### WRITE SOLUTION HERE
    subtotal = calculate_subtotal(order)
    tax = calculate_tax(subtotal)
    total = subtotal + tax
    total = round(total, 2)

    names = [item["name"] for item in order]

    return (names, total)
    
# This function is provided for you, and will print out the items in an order
def print_order(order):
    print('You have ordered ' + str(len(order)) + ' items')
    items = []
    items = [item["name"] for item in order]
    print(items)
    return order

# This function is provided for you, and will display the menu
def display_menu():
    print("------- Menu -------")
    for selection in menu:
        print(f"{selection}. {menu[selection]['name'] : <9} | {menu[selection]['price'] : >5}")
    print()

# This function is provided for you, and will create an order by prompting the user to select menu items
def take_order():
    display_menu()
    order = []
    count = 1
    for i in range(3):
        item = input('Select menu item number ' + str(count) + ' (from 1 to 5): ')
        count += 1
        order.append(menu[int(item)])
    return order

'''
Here are some sample function calls to help you test your implementations.
Feel free to change, uncomment, and add these as you wish.
'''
def main():
    order = take_order()
    print_order(order)

    subtotal = calculate_subtotal(order)
    print("Subtotal for the order is: " + str(subtotal))

    tax = calculate_tax(subtotal)
    print("Tax for the order is: " + str(tax))

    items, subtotal = summarize_order(order)

if __name__ == "__main__":
    main()