$1$h$.$ Give back the customer change

When the customer is done purchasing items, the machine

should give back the remaining balance to the customer.

Implement a method called output$\_$change that checks if

there is any change to be given back and, if so$,$ prints the

change in the following format:

It should then set the customer's balance to $0\mathrm{.}0,$ indicating

the change has been given back to the customer.

If no change needs to be given back, it should simply

print the messaqe:

Testing recommendations for output$\_$change:

When there is change $($i$.$e$.,$ balance $>0)$

When there is no change $($i$.$e$.,$ balance $=0)$

$1$i$.$ Remove an item from the vending

machine

If a snack is not selling well, the owner may want to remove

it completely from the selection so it will no longer be

restocked. Implement a method called remove$\_$item that

takes the name of a snack as a parameter, and removes it

from the vending machine. If successful, it should print the

following message:

$\{$ITEM$\}$ removed from inventory

If the item to be removed does not exist in the machine, it

should print the following message:

Testing recommendations for remove$\_$item:

Removing a valid item

Removing an invalid item $1$e$.$ Display the list of snacks and their

quantities

A vending machine should be able to display the list of

stacks, including their names, costs and quantities. Your

class should have a method called list$\_$items that

prints the following string if there are no items in the

machine $($i$.$e$.,$ an empty vending machine$)$:

No items in the vending machine

Otherwise, it should print the list of snacks with their

respective quantities in the following format, sorted

alphabetically based on the item name.

Hint: Python's sorted$()$ function can be used to sort

sequences and containers like lists and dictionaries. How to

use sorted$()$ is dependent on how you chose to store your

vending machine items.

Here's an example of sorting a dictionary by key.

And here's an example of sorting a list of dictionaries by key

using a lambda function: $1c.$ Get the price of an item in the vending

machine

Before making a purchase, the customer may need to check

the price of an item. Your class should have a method called

get$\_$item$\_$price that takes an item's name as a parameter

and returns the price of that item. If the item does not exist

in the vending machine, it should print the following and

return None:

Testing recommendations for get$\_$item$\_$price:

Get price of a valid item

Get price of an invalid item

$1d.$ Get the quantity of an item in the

vending machine

The owner may want to periodically check the quantity of a

snack to decide if it needs to be restocked. Your class

should have a method called get$\_$item$\_$quantity that

takes an item's name as a parameter, and returns the

quantity of that item. If the item does not exist in the vending

machine, it should print the following and return None:

Testing recommendations for get$\_$item$\_$quantity:

Get quantity of a valid item

Get quantity of an invalid item$1$a$.$ Implement the constructor

Create a class named VendingMachine and a constructor

that creates and initializes attributes. Other than self, the

constructor should NOT take any additional parameters. As

mentioned in the Important Notes section, it's up to you to

decide what variables to create in the constructor. If you

followed the suggestion in the Important Notes section, you

should already have an idea. You can always come back to

the constructor to modify and$/$or add attributes as needed.

$1$b$.$ Add items to the vending machine

Periodically, we may want to restock the current snacks in

the vending machine, or add brand new snacks. Your class

should have the method add$\_$item that takes an item's

name, price and quantity as parameters $($don$\text{'}$t forget

self too $...$ this will be your last reminder about self$).$ The

method should add the item to the vending machine. Note

that if the item already exists, the method should update the

price and add the quantity to the existing stock. $($At this

point, you should think deeply about how you want to hold

several pieces of information about every item currently in

the vending machine. Setting up an organized way to store

and handle this data now will help you tremendously going

forwards.$)$ When successfully added, the method should

print the quantity and the item name in the following format:

$\{$QUANTITY$\}\{$ITEM$\_$NAME$\}($s$)$ added to inventory

Here, QUANTITY $\}$ and $\{$ITEM$\_$NAME $\}$ are the actual quantity

and name of the item, respectively. Going forwards, we will

always use VARIABLE