Recycling Machine using the Python

ITECH1400 - Assignment 1 – Recycling Machine

Assignment Overview

You are tasked with creating a text-based program for simulating a Recycling Machine using the Python 3 programming language.

The assignment is broken up into four main components:

1.)  Design and model two classes: Recyclable Item and Recycling Machine

2.)  Create an activity chart which describes the behaviour of the Recycling Machine system

3.) Create a computer program that allows a user to enter items that are able to be recycled into a machine.  During the process the machine prompts the user for the type of item to be recycled and how many they have to enter. The machine keeps track of the number of each of the different items and keeps track of the total amount to pay the user until they indicate that they are finished. When they stop adding items, print out a receipt and given them the amount of money owing. The receipt should contain the following:

a.     A list showing how many of each item has deposited and the cost of each item.

b.     The total amount provided for each item

c.      The total money received.

4.)  Finally, explain and integrate some code into your Recycling Machine program that keeps track of how many items of each type are in the machine, and, if the machine is full, makes deposits of that item type unavailable. You machine should have at least 4 different products, and allow up to 50 of each product.

Your submission should consist of one document containing the first two parts of the assignment, and three Python scripts that implement the computer program (recycling machine.py, recyclable Item.py and main.py).

The main.py script runs the main logic of the program and will use instances of the Recycling Machine  and Recyclable Item classes to simulate depositing into a Recycling Machine.

You are provided with a Microsoft Word template to help you complete the first two parts of this assignment.

Towards the end of this document you will also be provided with the output of a simulated run of the completed computer program which may help you with this assignment.

Assignment Part 1 Details – Class Design

Think of a product that you can recycle that you might want to be able to deposit into a Recycling Machine, like maybe an empty soft drink can.

Start by listing all the properties of that object that you can think of – try to come up with at least ten general properties of a Recyclable Item and write these down in your Assignment_Part_1_<YOUR_STUDENT_ID>Microsoft Word document, provided for download in the assessment section of your Moodle shell.

Next, use the process of abstraction to cut the number of properties back to only ‘key’ properties – write these down in the next section of your Word document. Take a look at the week 2 lecture slides if you need a reminder on how to go about this.

Now, fill in the class diagram for your Item class in the Word document template provided. Your Recyclable Item class does not have to have any methods (i.e. functions) associated with it to perform any actions other than a constructor which takes and set the key properties that you’ve identified.

Next we’ll move on to Recycling Machine class – think about what information the Recycling Machine has to keep track of to allow you to successfully deposit an item to be recycled. There will only really be three key properties that the Recycling Machine cares about, and the Recycling Machine class should have the following five methods available: 

1)    A default constructor that takes no arguments and initialises a new object and its properties,

2)    accept_product(),

3)    select_product()

4)    payout(anAmount)

5)    print_receipt().

Fill in the class diagram for the RecyclingMachine class in the Word template, and that’s the first part completed!

Assignment Part 2 Details – Activity Flowchart

Using either the online website https://draw.io (preferred), or the applications Visio or Power point – create an activity diagram of how the program should operate to successfully enter their money, buy one or more products, provide change and print a receipt for the user.

Make sure to use the correct symbols in your diagram for starting, processes, decisions/branches, and ending the process.

Although you may be familiar with how a Recycling Machine works, if not then you can always look onlineRecycling Machine.

Don’t worry about taking payment to debit or credit cards, our RecyclingMachine will only provide cash.

Once you have completed your activity chart, add it to your assignment template document.

Assignment Part 3 Details – Software Implementation

You are free to implement the software however you see fit, however the functionality of the software should be able to match the following output. Note that in the below run of the program I have ‘hard-coded’ a small number of Recyclable Item instances so that products which exist can be purchased – in your code you should do the same.

Your program does not have to have the facility to add new recyclable items – just define a few and use them as demonstrated below. If the final option of STOP is chosen, the program should print the receipt and ask the user if they want to start again or quit.

Example Program Output

Balance: $0.0. Please select a product: (Can, Bottle, Paper, Stop): Can

How many cans do you have?:3

Please place 3 cans into machine.

Can accepted

Can accepted

Can accepted

You added 3can(s) for $0.20 each. You have $0.6. 

Balance: $0.6. Please select a product: (Can, Bottle, Paper): Bottle

How many bottles do you have?:1

Please place 1bottle into machine.

Bottle accepted

You added 1 can(s) for $0.50 each. You now have $1.10.

Please select a product: (Can, Bottle, Paper): STOP

-----Final Receipt ----- 

3 Can(s)                                   $0.6

1 Bottle(s)                      $1.0

Number of items 4

Amount paid:               $1.6

Thank you for recycling at FedUni!

(N)ext customer, or (Q)uit? q

>>> 

Part 4 – Code Explanation and Use

You are provided with the following two functions which you should

1.     Analyse to determine what they do & provide documentation comments for, and

2.     Incorporate into your final program solution.

Wherever there is a # followed by some underscores in the code below, you should write a short comment explaining what the below section of code is doing, and if there is space why it is doing it. Do part 1 of the above in the provided assignment 1 template document, rather than here!

# Function to: ___________________________
defget_float(prompt):
# ____________________________________
    value = float(0.0)
# ____________________________________
while True:
try:
# ____________________________________
value = float(input(prompt))
# ____________________________________
if value <0.0:
print("We don't accept negative money!")
continue
# ____________________________________
break
# ____________________________________
except ValueError:
return 0.0
# ____________________________________
return value

# Function to: ___________________________

defrun():

# ____________________________________

vm = RecyclingMachine()

# ____________________________________

next_customer = True

# ____________________________________

while next_customer:

# ____________________________________

vm.accept_product()

# ____________________________________

vm.identify_product()

# ____________________________________

vm.print_receipt()

# ____________________________________

while True:

# ____________________________________

answer = get_str("(N)ext customer, or (Q)uit?")

# ____________________________________

answer = answer.upper()

# ____________________________________

if answer == "N":

                   # ____________________________________

break

elifanswer == "Q":

# ____________________________________

exit()

else:

# ____________________________________

print("Invalid Response")