04 | Assignment 04

Part A

concepts: priming a while loop, executing a while loop, printing a menu, quitting a while loop, using sep="\n" (to print new lines), get user input to continue loop, use if and elif to control chosen output

In part A we will print a menu that will continue to (while) loop again and again. The goal is for it to look like this example that was shown in class. Be sure to change the menu and your code to be something original. That will make it your own and fire up extra neuron connections in your brain to make this program pattern more memorable.

MENU:
a: cut and fold brochures
b: deliver print jobs
q: quit
Enter a letter for more info around the shop:

The menu is short with only three options: a, b, and q for quit. Just having two choices makes it seem unnecessary to loop; however, you could create a menu with 10 to 20 items, like in a FAQ. In that case it makes sense for it to loop again and again to allow multiple interactions. The user could continue to choose various FAQs and read each one until they decided to quit by pressing q.

After the print menu runs, the user will be prompted to enter a letter a,b, or q. When the user enters a letter, an if and an elif statement will be necessary to print out the appropriate response to the letter choice. If the user types in a q, the program will exit without running the if or elif statement.

After the if or elif runs, the program returns back to the beginning then encounters the while statement and runs the program again. It the user was not given the option to quit, it would never stop looping. It would be necessary to "kill" the python session by closing down the application or terminal.

How to code this:

As much as possible type all of this out yourself as you will benefit from going through it line by line.

1. Create a lastname_first-initial_assignment_4 folder. Inside of that folder, create a file named while_menu.py.

2. On the first line of while_menu.py file, prime the while loop by typing:

menu_option = ''

This creates a variable with no data. Sort of like an empty box with a menu_option label. This gives the user a place to store his letter choice. It starts out empty so that the loop will run and then the user can control the loop.

3. On the next line of the program put in your while statement. In this case our while statement goes as follows:

while | some_variable  |  comparison operator   |  'string' |  FINAL COLON
-----   -------------     -------------------      --------    -----------
while | menu_option    |  != (is not equal to)  |  'q'      |  :

The above spaces and grid are for instructional clarity. You will need to type it like this:

while menu_option != 'q':

So if the user enters anything, any key at all, except a q, it will just keep looping. It takes an actual a or b for the if or elif to print a specific response. After you write the program, try it. You can enter anything. It will just loop and loop. It will only respond to you if you enter a, b, or q.

4. On the next line add a print function print() to present the menu to the user.

Use the regular method (non f-string) of separating the menu items with commas. If you forget to add the final sep="\n", the text will print all on one line as shown below:

Code:

print('MENU:','a: cut and fold brochures', 'b: deliver print jobs', 'q: quit')

Output:

MENU: a: cut and fold brochures b: deliver print jobs q: quit

Therefore, add a comma after the quit string and add the the sep="\n" to make each choice print out on a new line as is shown at the top of the assignment instructions.

After the user sees the menu they also need see a prompt to enter the input. This can't be combined with the menu because the input needs to be assigned to the menu_option variable. It is important to understand that the logic is tied to the if and the elif. The menu is just directions. The input message is just directions. What matters is that the variable gets stored and the if and the elif are watching for it.

Okay, now we are getting into the logic. This is where you construct your if and elif:

if menu_option == 'a':
   print('response a')
elif menu_option == 'b':
   print('response b')

This will complete this first part of assignment 4.

Part B

concepts: practice with f-strings and a nested while loop

For part B you will simply duplicate your while_menu.py file and name the duplicated file while_menu_nested.py it should be in the same lastname_first-initial_assignment_4 folder

In this version do not use the sep='\n' for new lines. Use a f-string like this:

print(f'''
Shop information FAQS:
a: cut and fold brochures
b: deliver print jobs
q: exit 
''')

Then under your elif add another variable = input('string (y or n): ') and a nested if else. The if will accept the y and the else will accept the n. Remember to use some other example other than what we did in class.

 if menu_option == 'a':
        print('The cutter and folder can be dangerous. Get training before using!')
    elif menu_option == 'b':
        van_driver = input('Are you comfortable driving a class B van? enter (y or n): ')
        if van_driver == 'y':
            print("Awesome! It would be great to have you help deliver on occasion!")
        else:
            print("We won't ask you to drive!")

When finished, zip up your folder and submit it in Canvas for Assignment 04.