Learning Goals

• use a dictionary to store menu items
• use a function to print formatted menu options
• use a while loop to create an interactive program
• check the user input using if branches
• check that an option is correct (verify that a dictionary key exists)
• use break to interrupt the program execution

Introduction

In this lab, we will be building an application that uses an interactive menu.

Let's say our high-level menu has the following options:

These key-option mappings will be stored in a dictionary in the main program.

print_main_menu() function

Write the print_main_menu() that accepts a dictionary of keys-options like the one shown above and prints the menu options stored in that dictionary in an easy-to-read format. Below is an example of the result of calling print_main_menu() (notice the question it asks at the top - it is part of the function output):

Example

Given the menu with the following options as mentioned above, the call to print_main_menu(main_menu) will output:

Program flow

The expected program flow is:

• The main program starts with a menu of options given above
• Loop indefinitely (while the user didn't choose to exit):
  • Print the menu to the user
  • Get the user's choice from input()
  • Check if the user's choice is a valid option in the menu (is it one of the dictionary keys?).
    • If the input is a valid option, print the option that user selected
    • If not, simply continue from the top of the loop
  • If the user entered 'Q', break the while loop

Instructions

1. Fix TODO 1: Add the options from the instructions to the_menu dictionary inside the main program.

2. Fix TODO 2: Implement the "Quit" option, breaking from the while loop if the user input is an uppercase OR lowercase "Q".

3. Fix TODO 3: Check whether a provided option is a valid menu option.

Each time a valid menu option is provided, the program "echoes" it back to the user as follows:

def print_main_menu(menu):
    """
    Given a dictionary with the menu,
    prints the keys and values as the
    formatted options.
    Adds additional prints for decoration
    and outputs a question
    "What would you like to do?"
    """

    
if __name__ == "__main__":
    the_menu = {} # TODO 1: add the options from the instructions
    opt = None

    while True:
        # print_main_menu(...) # TODO 1: uncomment, define the function, and call with the menu as an argument
        print("::: Enter an option")
        opt = input("> ")

        if opt == ...: # TODO 2: make Q or q quit the program
            print("Goodbye!\n")
            break # exit the main `while` loop
        else:
            if ...: # TODO 3: check of the character stored in opt is in the_menu dictionary
                print(f"You selected option {opt} to > {the_menu[opt]}.")
            else:
                print(f"WARNING: {opt} is an invalid option.\n")