I'm creating an invoice program that allows the user to select an item from a menu of products to either purchase or return. Once the user inputs the item ID and quantity desired, the program will read the inventory.txt file and write an UpdatedInventory.txt file, which will replace the inventory.txt file. The inventory.txt file is formatted like this:
ID
item
stock
price
When my program runs, it does not print correctly on the UpdatedInventory.txt file. There's a lot of code here so bear with me.
As an aside, I feel like it would simplify the code if every purchase the user made was added into a list rather than hard coded. Thanks for the help!
Here's my main code:
import InventoryFile
import os
def readFile ():
#open the file and read the lines
inventoryFile = open ('Inventory.txt', 'r')
raw_data = inventoryFile.readlines ()
#remove the new line characters
clean_data = []
for item in raw_data:
clean_item = item.rstrip ('\n')
clean_data.append (clean_item)
#read lists into objects
all_objects = []
for i in range (0, len(clean_data), 4):
ID = clean_data [i]
item = clean_data [i+1]
qty = float (clean_data [i+2])
price = float (clean_data [i+3])
#create inventory object
inventory_object = InventoryFile.Inventory (ID, item, qty, price)
all_objects.append (inventory_object)
return all_objects
def printMenu (all_data):
print ()
print ('Select an item ID to purchase or return: ')
print ()
print ('ID\tItem\t\t Quantity\t Price')
for item in all_data:
print (item)
print ()
print ('Enter another item ID or 0 to stop')
def modify ():
found = False
search = -1
while search == -1:
search = input ('Enter the ID of the product you would like to purchase: ')
try:
if search == '0':
print ('The inventory has been updated...')
break
except Exception:
search = -1
print ('ERROR: Please enter a valid number.')
else:
inventoryFile = open ('inventory.txt', 'r')
temp_file = open ('UpdatedInventory.txt', 'w')
ID = str (inventoryFile.readline ())
while ID != '':
item = str (inventoryFile.readline ())
qty = float (inventoryFile.readline ())
price = float (inventoryFile.readline())
inventory_object = InventoryFile.Inventory (ID, item, qty, price)
ID = ID.rstrip ('\n')
if ID == search:
purchase = -1
while purchase == -1:
purchaseEntry = float (input ('How many would you like to purchase? Negative numbers are returns'))
purchase = inventory_object.purchase (purchaseEntry)
if purchase is False:
purchase = -1
print ('ERROR: Insufficient stock!')
new_qty = inventory_object.restock (purchase)
transaction_object = InventoryFile.TransactionItem (ID, item, new_qty, price)
transaction_object.set_id (ID)
transaction_object.set_name (item)
transaction_object.set_qty (new_qty)
transaction_object.set_price (price)
ID = transaction_object.get_id ()
item = transaction_object.get_name ()
qty = transaction_object.get_qty ()
price = transaction_object.get_price ()
temp_file.write (ID + '\n')
temp_file.write (item + '\n')
temp_file.write (str (qty) + '\n')
temp_file.write (str (price) + '\n')
found = True
else:
temp_file.write (ID + '\n' )
temp_file.write (item + '\n')
temp_file.write (str (new_qty) + '\n')
temp_file.write (str (price) + '\n')
ID = inventoryFile.readline ()
if found:
print ('The file has been updated.')
else:
print ('That item was not found in the file.')
inventoryFile.close ()
temp_file.close ()
os.remove ('inventory.txt')
os.rename ('UpdatedInventory.txt', 'inventory.txt')
print ('Inventory has been updated.')
break
return search
def main ():
all_items = readFile ()
printMenu (all_items)
modify ()
main ()
Here's my Inventory Class file:
class Inventory ():
def __init__ (self, new_id, new_name, new_stock, new_price):
self.__id = new_id
self.__name = new_name
self.__stock = new_stock
self.__price = new_price
def get_id (self):
return self.__id
def get_name (self):
return self.__name
def get_stock (self):
return self.__stock
def get_price (self):
return self.__price
def restock (self, new_stock):
if new_stock < 0:
print ('ERROR')
return False
else:
self.__stock += new_stock
return True
def purchase (self, purch_qty):
if self.__stock >= purch_qty:
self.__stock -= purch_qty
return self.__stock
else:
print ('ERROR: Insufficient stock')
return False
def __str__ (self):
return self.__id + '\t' + self.__name + '\t' + \
format (self.__stock, '7.2f') + format (self.__price, '7.2f')
class TransactionItem (Inventory):
def __init__ (self, new_id, new_name, new_qty, new_price):
self.__qty = new_qty
Inventory.__init__(self, new_id, new_name, new_qty, new_price)
def get_id (self):
return self.__id
def set_id (self, new_id):
self.__id = new_id
def get_name (self):
return self.__name
def set_name (self, new_name):
self.__name = new_name
def get_qty (self):
return self.__qty
def set_qty (self, new_qty):
self.__qty = new_qty
def get_price (self):
return self.__price
def set_price (self, new_price):
self.__price = new_price
def calc_cost (self):
total = purch_qty * self.__price
def __str__ (self):
return self.__id + '\t' + self.__name + '\t' + \
format (self.__qty, '7.2f') + format (self.__price, '7.2f') + \
format (total, '7.2f')
Here is my inventory.txt file:
244
Large Cake Pan
7
19.99
576
Assorted Sprinkles
3
12.89
212
Deluxe Icing Set
6
37.97
827
Yellow Cake Mix
3
1.99
194
Cupcake Display Board
2
27.99
285
Bakery Boxes
7
8.59
736
Mixer
5
136.94
And here is what the updated inventory txt looks like after I input product ID 244, and purchase quantity of 5.
244
Large Cake Pan
4.0
19.99
576
Assorted Sprinkles
4.0
12.89
212
Deluxe Icing Set
4.0
37.97
827
Yellow Cake Mix
4.0
1.99
194
Cupcake Display Board
4.0
27.99
285
Bakery Boxes
4.0
8.59
736
Mixer
4.0
136.94
I've disabled TransactionItem. This seems to be working (I've combined the script files):
import os
class Inventory ():
def __init__(self, new_id, new_name, new_stock, new_price):
self.__id = new_id
self.__name = new_name
self.__stock = new_stock
self.__price = new_price
def get_id(self):
return self.__id
def get_name(self):
return self.__name
def get_stock(self):
return self.__stock
def get_price(self):
return self.__price
def restock(self, new_stock):
if new_stock < 0:
print('ERROR')
return False
else:
self.__stock += new_stock
return True
def purchase(self, purch_qty):
if self.__stock >= purch_qty:
self.__stock -= purch_qty
return self.__stock
else:
print('ERROR: Insufficient stock')
return False
def __str__(self):
return self.__id + '\t' + self.__name + '\t' + \
format(self.__stock, '7.2f') + format(self.__price, '7.2f')
class TransactionItem (Inventory):
def __init__(self, new_id, new_name, new_qty, new_price):
self.__qty = new_qty
Inventory.__init__(self, new_id, new_name, new_qty, new_price)
def get_id(self):
return self.__id
def set_id(self, new_id):
self.__id = new_id
def get_name(self):
return self.__name
def set_name(self, new_name):
self.__name = new_name
def get_qty(self):
return self.__qty
def set_qty(self, new_qty):
self.__qty = new_qty
def get_price(self):
return self.__price
def set_price(self, new_price):
self.__price = new_price
def calc_cost(self):
self.total = purch_qty * self.__price
def __str__(self):
return self.__id + '\t' + self.__name + '\t' + \
format (self.__qty, '7.2f') + format (self.__price, '7.2f') + \
format(self.total, '7.2f')
def readFile():
# open the file and read the lines
inventoryFile = open('Inventory.txt', 'r')
raw_data = inventoryFile.readlines()
# remove the new line characters
clean_data = []
for item in raw_data:
clean_item = item.rstrip('\n')
clean_data.append(clean_item)
# read lists into objects
all_objects = []
for i in range(0, len(clean_data), 4):
ID = clean_data[i]
item = clean_data[i + 1]
qty = float(clean_data[i + 2])
price = float(clean_data[i + 3])
# create inventory object
inventory_object = Inventory(ID, item, qty, price)
all_objects.append(inventory_object)
return all_objects
def printMenu(all_data):
print()
print('Select an item ID to purchase or return: ')
print()
print('ID\tItem\t\t Quantity\t Price')
for item in all_data:
print(item)
print()
print('Enter another item ID or 0 to stop')
def modify():
found = False
search = -1
while search == -1:
search = input(
'Enter the ID of the product you would like to purchase: ')
try:
if search == '0':
print('The inventory has been updated...')
break
except Exception:
search = -1
print('ERROR: Please enter a valid number.')
else:
inventoryFile = open('inventory.txt', 'r')
temp_file = open('UpdatedInventory.txt', 'w')
ID = str(inventoryFile.readline())
while ID != '':
item = str(inventoryFile.readline())
qty = float(inventoryFile.readline())
price = float(inventoryFile.readline())
inventory_object = Inventory(ID, item, qty, price)
ID = ID.rstrip('\n')
item = item.rstrip('\n')
if ID == search:
purchase = -1
while purchase == -1:
purchaseEntry = float(
input('How many would you like to purchase? Negative numbers are returns'))
purchase = inventory_object.purchase(purchaseEntry)
if purchase is False:
purchase = -1
print('ERROR: Insufficient stock!')
#new_qty = inventory_object.restock(purchase)
#transaction_object = TransactionItem(
# ID, item, new_qty, price)
#transaction_object.set_id(ID)
#transaction_object.set_name(item)
#transaction_object.set_qty(new_qty)
#transaction_object.set_price(price)
#ID = transaction_object.get_id()
#item = transaction_object.get_name()
#qty = transaction_object.get_qty()
#price = transaction_object.get_price()
qty = inventory_object.get_stock()
price = inventory_object.get_price()
temp_file.write(ID + '\n')
temp_file.write(item + '\n')
temp_file.write(str(int(qty)) + '\n')
temp_file.write(str(price) + '\n')
found = True
else:
temp_file.write(ID + '\n')
temp_file.write(item + '\n')
temp_file.write(str(int(qty)) + '\n')
temp_file.write(str(price) + '\n')
ID = inventoryFile.readline()
if found:
print('The file has been updated.')
else:
print('That item was not found in the file.')
inventoryFile.close()
temp_file.close()
os.remove('inventory.txt')
os.rename('UpdatedInventory.txt', 'inventory.txt')
print('Inventory has been updated.')
break
return search
def main():
all_items = readFile()
printMenu(all_items)
modify()
main()
I hope it helps!