A supermarket owner needs to improve his supermarket's business process.
To do that, he wants to provide his customers a self-service cashier app.
The supermarket customers can see the total amount of their transaction by inputting the items information to the order list.
The cashier module is able to:
- Create a transaction ID containing all items in order list
- Add an item, its quantity, and its price to the order list
- Update the name of an item
- Update the quantity of an item
- Update the price of an item
- Delete an item based on its name
- Reset the transaction data, erasing all items in order list
- Check whether the item data inputted is correct
- Show the total price of all items in order list
graph TB
A((Start)) --> B(Create a transaction ID)
B --> C(Add a new item to order list)
C --> D{Add another item?}
D -- Yes --> C
D -- No --> E{Update the items in the list?}
E -- No --> F(Check order)
E -- Yes --> G0(Edit the items)
G0 --> G1(Update an item name)
G0 --> G2(Update an item quantity)
G0 --> G3(Update an item price)
G0 --> G4(Delete an item)
G0 --> G5(Reset the transaction,<br/>deleting all items)
G6{Finished editing?}
G1 --> G6
G2 --> G6
G3 --> G6
G4 --> G6
G5 --> C
G6 -- Yes --> F
G6 -- No --> G0
F --> H{All data correct?}
H -- Yes --> I(Calculate total price)
H -- No --> E
I --> J{Is discounted?}
J -- No --> K1(Show total price)
J -- Yes --> K2(Show initial total price, <br/> amount of discount, and the final price)
L((End))
K1 --> L
K2 --> L
class Transaction:
def __init__(self):
self.order_items = {}By initializing the Transaction Class, it will create a dictionary which will contain the order items information.
def add_item(self, item_name, item_qty, item_price):
self.item_name = str(item_name).title()
try:
self.item_qty = int(item_qty)
self.item_price = int(item_price)
try:
assert self.item_qty >= 0
assert self.item_price >= 0
self.order_items[self.item_name] = [self.item_qty, self.item_price]
except:
print("Tidak dapat menambahkan item. \nJumlah dan harga barang tidak boleh negatif.\n")
except:
print("Tidak dapat menambahkan item. \nJumlah dan harga item harus berupa angka.\n")Input item name, quantity, and price as arguments for this method.
it will store the item name as a key and its quantity and price as value to the transaction dictionary.
If the arguments type are incorrect, the items will not be added and will show an error message instead.
def show_order_table(self):
order_table = [] # Define the order table as a list
table_header = ['No','Nama Item','Jumlah Item',
'Harga/Item','Harga Total'] # Define the header texts
order_table.append(table_header) # Append the header to the list
n = 0
for key, value in self.order_items.items():
n += 1
table_no = n
item_name = key
item_qty = value[0]
item_price = value[1]
amount = item_qty * item_price
item_data = [table_no, item_name, item_qty,
item_price, amount]
order_table.append(item_data) # Append the item data into the table list
# Print the table
print(tabulate(order_table, headers="firstrow"))This methods shows the items inside the transaction dictionary as a table using the tabulate module.
On the other hand, this method also calculates and displays the total amount of each items based on its quantity and price.
def update_item_name(self, item_name, new_item_name):
self.item_name = str(item_name)
self.new_item_name = str(new_item_name)
try:
self.order_items[self.new_item_name] = self.order_items[self.item_name]
del self.order_items[self.item_name] # Delete the old key
except:
print("Gagal mengubah nama item. \nNama item tidak ditemukan\n")
Update the name of an item in the list by providing the item name and its new name as the arguments to this method.
This method will give an error message if:
- The item name inputted isn't found in the order list
def update_item_qty(self, item_name, new_item_qty):
self.item_name = str(item_name)
try:
self.new_item_qty = int(new_item_qty) # Check if the quantity is a number
try:
assert self.item_qty >= 0
try:
self.order_items[self.item_name][0] = self.new_item_qty # Check if item name exists
except:
print("Gagal mengubah jumlah item. \nNama item tidak ditemukan.\n")
except:
print("Tidak dapat memperbarui jumlah. \nJumlah barang tidak boleh negatif.\n")
except:
print("Jumlah item harus berupa angka.\n")Update the quantity of an item in the list by providing the item name and its new quantity as the arguments to this method.
This method will give an error message if:
- The item quantity inputted is not an integer
- The item quantity inputted is negative, less than 0
- The item name inputted isn't found in the order list.
def update_item_price(self, item_name, new_item_price):
self.item_name = str(item_name)
try:
self.new_item_price = int(new_item_price) # Check if the price is a number
try:
assert self.item_qty >= 0
try:
self.order_items[self.item_name][1] = self.new_item_price # Check if item name exists
except:
print("Gagal mengubah harga. \nNama item tidak ditemukan.\n")
except:
print("Tidak dapat memperbarui harga. \nHarga barang tidak boleh negatif.\n")
except:
print("Harga item harus berupa angka.\n")Update the price of an item in the list by providing the item name and its new item price as the arguments to this method.
This method will give an error message if:
- The item price inputted is not an integer
- The item price inputted is negative, less than 0
- The item name inputted isn't found in the order list.
def delete_item(self, item_name):
self.item_name = str(item_name)
try:
del self.order_items[self.item_name]
except:
print("Gagal menghapus item. \nNama item tidak ditemukan.\n")Delete an item in the order list by providing the name of the item as the argument to this method.
This method will give an error message if:
- The item name inputted isn't found in the order list.
def reset_transaction(self):
transaction = {}
self.order_items = transaction
print("Semua item berhasil dihapus.\n")This method will reset the transaction, deleting all items inside the order list, left it as an empty dictionary.
When the process is done, it will give a success message.
def check_order(self):
for key, value in self.order_items.items():
item_name = key
item_qty = value[0]
item_price = value[1]
if type(item_name) == str and type(item_qty) == int and type(item_price) == int:
print(f"[v] {item_name :<12}: data sudah sesuai.")
else:
if type(item_name) != str:
print(f"[x] {item_name :<12}: nama barang harus berupa teks.")
else:
pass
if type(item_qty) != int:
print(f"[x] {item_name :<12}: jumlah item harus berupa angka.")
else:
pass
if type(item_price) != int:
print(f"[x] {item_name :<12}: harga item harus berupa angka.")
else:
passThis method will check whether the item inputted into the order list has certain data types.
It will show a success message if the key and the values of the item is in expected data type.
On the other hand, it will show an error message if:
The key or value of the item is not in certain data type.
def total_price(self):
self.total_price = 0
for value in self.order_items.values():
item_qty = value[0]
item_price = value[1]
self.total_price += (item_qty * item_price)
is_discounted, discount = self.is_discounted(self.total_price)
self.final_price = self.total_price * (1 - discount)
if is_discounted == True:
print(f"Total belanja Anda: Rp{self.total_price}.")
print(f"Anda mendapat diskon {discount * 100}%.")
print(f"Anda hanya perlu membayar: Rp{self.final_price}.")
else:
print(f"Total belanja Anda: Rp{self.total_price}.")
print("Belanja di atas Rp200.000 untuk mendapat diskon.")This method calculates the sum of the amount of each item in the order list.
It will also show how much the customer will pay after the discount (if applicable).
def is_discounted(self, total_price):
self.total_price = total_price
if self.total_price <= 200000:
is_discounted = False
discount = 0.0
else:
is_discounted = True
if self.total_price > 500000:
discount = 0.1
elif total_price > 300000:
discount = 0.08
elif total_price > 200000:
discount = 0.05
return is_discounted, discountBased on the total price inputted as argument, this method will confirm whether a transacation will get a discount or not. It will decide how much discount the transaction is going to get.
This method returns the discount status (boolean) and the discount rate (float).
pip install requirements.txt
import cashier
trnsct_123 = cashier.Transaction()Add an item to the order list.
trnsct_123.add_item("Ayam Goreng", 2, 20000)Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ----------- ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
Change the item name from "Ayam Goreng" to "Pasta Gigi."
trnsct_123.update_item_name("Ayam Goreng", "Pasta Gigi")Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ---------- ------------- ------------ -------------
1 Pasta Gigi 2 20000 40000
Change the item quantity of "Pasta Gigi" to 4.
trnsct_123.update_item_qty("Pasta Gigi", 4)Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ---------- ------------- ------------ -------------
1 Pasta Gigi 4 20000 40000
Change the item price of "Pasta Gigi" to 15000.
trnsct_123.update_item_price("Pasta Gigi", 15000)Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ---------- ------------- ------------ -------------
1 Pasta Gigi 4 15000 40000
Given your order list consisting these items:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
2 Pasta Gigi 3 15000 45000
3 Mainan Mobil 1 200000 200000
4 Mie Instant 5 3000 15000
Delete an item named "Pasta Gigi".
trnsct_123.delete_item("Pasta Gigi")Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
2 Mainan Mobil 1 200000 200000
3 Mie Instant 5 3000 15000
Given your order list consisting these items:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
2 Pasta Gigi 3 15000 45000
3 Mainan Mobil 1 200000 200000
4 Mie Instant 5 3000 15000
Reset the transaction.
trnsct_123.reset_transaction()The output:
Semua item berhasil dihapus.
Show the item ordered as a table.
trnsct_123.show_order_table()The output:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
Given your order list consisting these items:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
2 Pasta Gigi 3 15000 45000
3 Mainan Mobil 1 200000 200000
4 Mie Instant 5 3000 15000
Check whether the item datas inputted are okay or not.
trnsct_123.check_order()The output:
[v] Ayam Goreng : data sudah sesuai.
[v] Pasta Gigi : data sudah sesuai.
[v] Mainan Mobil: data sudah sesuai.
[v] Mie Instant : data sudah sesuai.
Given your order list consisting these items:
No Nama Item Jumlah Item Harga/Item Harga Total
---- ------------ ------------- ------------ -------------
1 Ayam Goreng 2 20000 40000
2 Pasta Gigi 3 15000 45000
3 Mainan Mobil 1 200000 200000
4 Mie Instant 5 3000 15000
Check the total price of all the items and the final price you need to pay.
trnsct_123.total_price()The output:
Total belanja Anda: Rp300000.
Anda mendapat diskon 5.0%.
Anda hanya perlu membayar: Rp285000.0.