Description
1. Introduction
Congratulations! You are finally launching the business you’ve been planning for
years – an online PC shop! This shop will allow customers to buy from one of two
main categories: custom builds (a computer that is built and customized to meet
specific customer needs) and pre-built machines (complete systems assembled by
well-known manufacturers using balanced hardware configurations).
You
currently only carry a relatively small (but powerful) inventory of items, but you
want to give your customers the best experience possible anyways. You will be
writing a program (using Python) that allows users to order items from your shop.
In this assignment, you will get practice with:
– Creating functions
– Calling functions and using returned values
– User input in a loop
– Conditionals
– Lists, 2-D lists, and tuples
– String formatting for clean output
To begin, let’s note a few things. If your customers are building a computer, they
absolutely must have these essential parts:
1. Central Processing Unit (CPU) for executing instructions
2. Motherboard for allowing communication between crucial components of
the system
3. Random Access Memory (RAM) for storing information that needs to be
retrieved quickly
4. Power Supply Unit (PSU) for powering the components within the system
5. Either a Solid State Drive (SSD) or a Hard Disk Drive (HDD) (or both) for
storage
6. A case for storing the components
Often, people will also want a Graphics Card to add to their build if they plan on
doing things like gaming, video editing, or 3D graphics modeling in which
processing graphical data as efficiently as possible is important.
With that out of the way, let’s also note that sometimes certain PC parts are not
compatible with each other within a build (for example, an Intel i7-11700K CPU
and an MSI B550-A PRO motherboard are not compatible) and the PC will not
work when a build is attempted. Your shop tries to ensure that all components
can be used together in a build, however sometimes it’s just not possible.
** Note that you do not need to know about component compatibility beyond
what is explicitly being told to you for this assignment.
2. Files
For this assignment, you must create one file: shop.py. Note that this file should
by shop.py precisely (not Shop.py, shop.py.py, or any variation of these things).
3. Instructions
In the shop.py file, create a function called pickItems() which takes no parameters
and acts as the heart of the program. This function will mainly consist of a userinput-driven system for ordering PCs, but can (and definitely should) get help
from separate helper functions (you’ll decide what those helper functions are and
what they do).
The pickItems() function will walk the user through their order
using print statements and collecting user input, and will ultimately return a list
with the prices of each PC a user has purchased (whether they built it
themselves or bought a pre-built).
3.1 Storing your inventory as a list of lists
You have a static inventory (we’ll assume you have unlimited resources of each
offered item). The types of PC components you have in stock for custom builds
are listed below (and can be copied directly into your shop.py file):
SSD = [[‘1’, ‘250 GB’, 69.99], [‘2’, ‘500 GB’, 93.99], [‘3’, ‘4 TB’, 219.99]]
HDD = [[‘1’, ‘500 GB’, 106.33], [‘2’, ‘1 TB’, 134.33]]
CPU = [[‘1’, ‘Intel Core i7-11700K’, 499.99], [‘2’, ‘AMD Ryzen 7 5800X’, 312.99]]
MOTHERBOARD = [[‘1’, ‘MSI B550-A PRO’, 197.46], [‘2’, ‘MSI Z490-A PRO’, 262.30]]
RAM = [[‘1′, ’16 GB’, 82.99], [‘2′, ’32 GB’, 174.99]]
GRAPHICS_CARD = [[‘1’, ‘MSI GeForce RTX 3060 12GB’, 539.99]]
PSU = [[‘1’, ‘Corsair RM750’, 164.99]]
CASE = [[‘1’, ‘Full Tower (black)’, 149.99], [‘2’, ‘Full Tower (red)’, 149.99]]
And the types of pre-built machines you have to offer are:
PREBUILTS = [[‘1’, ‘Legion Tower Gen 7 with RTX 3080 Ti’, 3699.99], [‘2’,
‘SkyTech Prism II Gaming PC’, 2839.99], [‘3’, ‘ASUS ROG Strix G10CE Gaming PC’,
1099.99]]
In these 2-D lists, the inner-list structure represents:
[the ID associated with that component (string), the name of the product being
offered (string), and the price of the product (float)]
3.2 Hardware Incompatibilities
As mentioned previously, some components are incompatible with each other.
For example, some motherboards do not have the correct CPU socket (and
supported chipset) for certain CPU models (this is all jargon you don’t need to be
familiar with, but could research if you were interested).
When looking at the hardware we offer, we notice that the Intel Core i7-11700K
CPU is NOT compatible with the MSI B550-A PRO motherboard, and the AMD
Ryzen 7 5800X CPU is NOT compatible with the MSI Z490-A PRO motherboard.
This needs to be taken into consideration when showing customers what
components are available for their build.
If the user is building a custom machine and chooses option ‘1’ for their CPU (Intel
Core i7-11700K), your program should only present and allow them to select
option ‘2’ (MSI Z490-A PRO) to them within the motherboard selection. If the user
selects option ‘2’ for their CPU (AMD Ryzen 7 5800X), the program should only
present and allow them to select option ‘1’ (MSI B550-A PRO) within the
motherboard selection stage. Examples of this are shown below.
3.3 Storage Selection
When purchasing storage (where data is permanently stored on your computer),
the customer can either select an HDD, an SSD, or both. Thus, you must allow
them to decline purchasing the HDD or the SSD if they wish. To ‘decline’, the user
should be able to input ‘x’ OR ‘X’. If the user has already declined purchasing an
SSD, you must ensure that they select a HDD. Examples of this are shown below.
3.4 Order of Component Selection
It is important to note that customers MUST purchase one CPU, one
motherboard, one RAM option, one PSU option, one SSD or HDD (or BOTH – they
can decline purchasing one or the other if they wish), and one case. In addition,
recall that they do not NEED to purchase a graphics card – they can decline with
‘x’ or ‘X’.
Once your program is launched, If the user wishes to build a custom PC, they must
enter 1. Then, you should guide them through their options in the exact order of:
CPU, Motherboard (making sure the motherboards shown are compatible with
the CPU they have just chosen), RAM, PSU, the case, SSD, HDD, and Graphics
card.
This ensures that, during testing, our input is matching up with what your
program is expecting. If you do not prompt the user to select the components in
this order, the autograder will fail all of the test cases and you will receive a
mark of 0 on that portion.
3.5 Ensuring the Customer Enters a Valid Input
When the user selects an invalid option (one that does not appear as available for
selection), the program should continue prompting for input until their entry is
valid, as shown in the image below. We can see here that the program continues
asking for input until a valid option is chosen.
When choosing a graphics card, ensure that ‘x’ and ‘X’ are included in the
allowable input (as the user does not necessarily need one).
When choosing storage, ensure that ‘x’ and ‘X’ are included in allowable input for
the HDD if the user selected an SSD. If the user did not select an SSD, ensure that
‘x’ and ‘X’ are not included in the allowable input.
For all other necessary hardware, the user should not be able to select ‘x’ or ‘X’
(as these parts are required).
3.6 What is Returned from pickItems()?
When building a custom-build, once all of the parts are successfully picked, the
total price of all the parts combined should be added to a list that will eventually
be returned from pickItems() (once the user selects that they’re ready to
checkout with ‘3’). The user, if they wish, can also continue to either build
another PC (by pressing ‘1’), or add a pre-built PC to their cart (by pressing ‘2’).
The pickItems() function should return a list of prices of each PC ordered by one
customer in the order that they were purchased.
Again, one customer could
order as many custom-built and pre-built machines as they wish (before pressing
‘3’ to checkout) and the total price of each should be returned in a list in the
order that the customer purchased them once they do press ‘3’ to checkout.
Note that if the user does not order anything, an empty list should be returned.
3.7 The Final Print Statement
After the user selects ‘3’ to checkout, you should simply print the list that is
returned from pickItems().
3.8 Other Important Notes
After completing a custom-build, you should print ‘You have selected all of the
required parts! Your total for this PC is $___’ where ‘___’ is replaced with the
price for that specific PC. If a pre-built is added, you should print ‘Your total price
for this pre-built is $___’ where ‘___’ is replaced with the price for that specific
pre-built.
This allows the user to know how much every individual PC costs before checking
out.
4. User Interaction
The following five images demonstrate the expected flow of the program.
Important Notes:
– The number that the user inputs needs to be the number in the first index
of the item they are selecting, otherwise known as the ID (for example, if
they are purchasing 32GB of RAM, they need to enter ‘2’. This is so that
when we test your code in Gradescope, our input will match up with the
values that your program is looking for.
– If the user can decline selecting an item (for example, the SSD, HDD, or
Graphics card), allow them to select ‘X’ (they should be able to enter a
capital ‘X’ or lowercase ‘x’) in order to not purchase that piece of hardware.
– The exact text that you print to the user should be as similar as possible to
the examples provided above. This makes grading easier.
Hints:
– You must ensure that the user is only selecting one of the offered values
(for example, for the SSD, those values would be ‘1’, ‘2’, ‘3’, ‘x’, or ‘X’). To
do this, you could write a helper function like ‘extract(list)’ that returns a
list of the FIRST element of each list within the list of hardware. So, for SSD,
it would return [‘1’, ‘2’, ‘3’] (and then you could add ‘x’ and ‘X’ manually)
The usage could look something like:
while (SSD_pick not in extract(SSD) and SSD_pick != ‘x’ and SSD_pick != ‘X’):
SSD_pick = input(‘Choose the number that corresponds with the
part you want (or X to not get an SSD): ‘)
This will keep querying the user for a value until they enter an ‘permitted’
value.
– When a user is purchasing a HDD, you should check if they have already
purchased an SSD (and had not pressed ‘x’ or ‘X’). This can be done with a
simple ‘if-else’ statement. If they have, you can allow ‘x’ or ‘X’ to be an
allowable input. If they haven’t, you should ensure that they choose one of
the available HDD options so that the PC will work upon building it.
Tips and Guidelines
– Add comments throughout your code to explain what each section of the
code is doing and/or how it works. This is crucial in obtaining part-marks.
– Ensure that both ‘x’ and ‘X’ work as inputs to the program, where they are
applicable.
– You are encouraged to create and run your own tests to ensure that your
code works in many different cases (you can also use the images provided
within this document to determine whether your program is working as
expected or not).
– When submitting your assignment on Gradescope, please submit shop.py
only.
– Ensure that when printing prices, you are using two digits after the decimal
point.
Rules
– Read and follow the instructions carefully.
– Only submit the python file described in the files section of this document.
– Submit the assignment on time. Late submissions will receive a late penalty
of 10% per day (except where late coupons are used).
– Forgetting to submit a finished assignment is not a valid excuse for
submitting late.
– Submissions must be done on Gradescope. They will not be accepted by
email.
– You may re-submit your code as many times as you would like. However,
re-submissions that come in after the due date will be considered late and
subjected to late penalties.
– Assignments will be run through a similarity checking software to check for
code that looks very similar to that of other students. Sharing or copying
code in any way is considered plagiarism and may result in a mark of zero
(0) on the assignment and/or reported to the Dean’s Office. Work is to be
done individually.
Submission
Assignments cannot be submitted by email, only through Gradescope.
Marking Guidelines
The assignment will be marked as a combination of your auto-graded test results,
manual grading of your code logic, comments, formatting, style, etc. Below is a
breakdown of the marks for this assignment:
[50 marks] Auto-graded Tests
[20 marks] Code logic and completeness
[10 marks] Comments
[10 marks] Code formatting
[10 marks] Meaningful and properly formatted variables
Total: 100 marks
