Question

Explain what the code is doing line from line explanations please or summarize lines with an explanation 

def displayCart(): #displays the cart function
     """displayCart function - displays the items in the cart
       ---------------------------------------------------------------------"""
     import os
     os.system('clear')    
     print("\n\nCart Contents:")
     print("Your selected items:", cart)
     
def catMenu():  #function that displays the category menu
    """catMenu function - displays the categories user picks from
       ---------------------------------------------------------------------"""
    import os
    os.system('clear')
    print("""
    1 - Books
    2 - Electronics
    3 - Clothing
    d - display cart contents
    x - checkout
    """)  
    category = input('\nSelect one of the categories or checkout:')
    return category

def log_File(logfile,logrecord): #function that controls the log file
    """Function that appends the log activity.
       ------------------------------------------------------------------"""
    log= open(logfile,"a")
    log.writelines(logrecord)
    log.close()
    
def itemDescription (category): #function that reads the category's file 
    """Reads the category's text file that has the inventory items for the chosen
       category and returns a list with the item descriptions and prices.
       -----------------------------------------------------------------------------"""
    import os
    os.system('clear') 
    fi = open(category + '.txt',"r", encoding = "ISO-8859-1") 
    itemfile = fi.readlines()    # list of item descriptions and price
    itemlist = []
    for i in itemfile:           # creates item list 
        if len(i) > 1:           
            d = i.split(',') #splits the list at the comma
            d[0] = d[0].strip()     #Item name
            d[1] = float(d[1].strip()) # Item price
            d[2] = int(d[2].strip()) #Item quantity
            itemlist.append(d) #adds to list
    fi.close()
    return itemlist
def itemMenu (category, itemList): #function that displays the items to choose from in menu form
    """itemMenu function - displays the menu of items
       ---------------------------------------------------------------------"""
    import os
    os.system('clear')   
    print ('\n\n\t\t\t\t\t ' + category,'menu')
    print('\n\t\t\t {0:3s} \t {1:26s}  {2:8s}'.format('No.', 'Item Description', 'Price '))
    print('\t\t\t {0:3s} \t {1:26s} {2:8s}'
          .format('===', '===========================', '========')) 
    
    for n in range(0, len(itemList)):
        print('\t\t\t {0:2d}  \t{1:26s} \t ${2:8.2f}'.format(n+1,itemList[n][0], itemList[n][1])) #formats list
    print('\t\t\t  {0:2s} \tdisplay cart contents'.format("d"))
    print('\t\t\t  {0:2s} \tcheckout'.format("x"))
    choice = input('\nSelect the ' + category + ' number or checkout:')
    return choice
def confirmAdd(itemList, category, cart): #Confirms item function
    """confirmAdd function - confirms the users selected item and adds the item to cart
       ---------------------------------------------------------------------"""
    import os
    os.system('clear')
    confirm = input(" Would you like to add one " + itemList[category-1][0] + " (y/n?):")
    if confirm == 'y':
        found = False #if the item isn't added more than once
        for d in cart:
            if itemList[category-1][0] == d[0]: 
                found = True #if the item is added more than once add one to quantity
                d[2] += 1 #increments quantity by 1 if multiple of same item is added to cart
                break
        if not found:
            cart.append(itemList[category-1])
                              
# Global code
book_list = itemDescription('books')
elect_list = itemDescription('electronics')
cloth_list = itemDescription('clothing')

date=str(datetime.datetime.now())
lf= "IT109A9Log.txt" #log file where all information is stored

more_carts = 'y'     
carts = 0            
total_items = 0       
total_cost = 0.0     

while more_carts == 'y':
    cart = []        
    more_items = 'y'
    while more_items == 'y':
        category=catMenu() #Category function
        if category == 'x':
            more_items = 'n'
            break
        elif category == 'd':
             displayCart() #Display cart function         
        elif category not in '123':
            print('Invalid category selected')
            continue
        if category == '1':
            choice = 0
            while choice != 'x':
                choice = itemMenu('Book', book_list) 
                if choice == 'x':
                     continue
                elif choice == 'd':
                     displayCart() #display cart function 
                elif int(choice) <= len(book_list):
                    confirm = confirmAdd(book_list,int(choice),cart)  #Confirm for books
                else:
                     print('Invalid item selected') 
        elif category == '2':
             choice = 0
             while choice != 'x':
                 choice = itemMenu('Electronics', elect_list) 
                 if choice == 'x':
                     continue
                 elif choice == 'd':
                     displayCart() #display cart function 
                 elif int(choice) <= len(elect_list):
                     confirm = confirmAdd(elect_list,int(choice),cart)  #Confirm for elecs
                 else:
                     print('Invalid item selected') 
        elif category == '3':      
              choice = 0
              while choice != 'x':
                  choice = itemMenu('Clothing', cloth_list) 
                  if choice == 'x':
                     continue
                  elif choice == 'd':
                       displayCart() #display cart function 
                  elif int(choice) <= len(cloth_list):
                       confirm = confirmAdd(cloth_list,int(choice),cart)  #Confirm for clothing
                  else:
                     print('Invalid item selected') 
    if category == 'x':
        print('\t\tCheckout selected')
        displayCart() 
    cart_items, cart_cost = 0, 0.0
    os.system('clear')
    for item in cart:
        cart_items += item[2] #quantity calculation
        cart_cost += item[1] * item[2] #QTY * price
    print('\nTotal number of items:', cart_items)
    print('\nTotal cost of your items:${0:8.2f}'.format(cart_cost))
    total_items += cart_items
    total_cost += cart_cost
    if cart_items > 0:
        carts += 1
    cartlog_list= ['\n\nDate: ' + date,  
           '\nType of log: Cart', 
           '\nCart Number: ' + str(carts),
           '\nTotal number of items for the cart: ' + str(cart_items),
           '\nTotal cost of items:${0:8.2f}'.format(cart_cost)]
    log_File(lf,cartlog_list) #log of carts

    more_carts = input('\nWould you like more carts(y/n)? ')


sessionLog_List= ['\n\nDate: ' + date,
           '\nType of log: Session',
           '\nNumber of carts: ' + str(carts),
           '\nTotal number of items: '+ str(total_items),
           '\nTotal cost of items:${0:8.2f}'.format(total_cost)]
log_File(lf,sessionLog_List) #log of session

#final output
os.system('clear')    
print('\n\n\tTotal number of carts: ', carts)
print('\tTotal number of items: ', total_items)
print('\tTotal cost of items:  ${0:8.2f}'.format(total_cost))



input('\n\nHit Enter to end program')
    

Answer 1

## updated the code lines with descriptions wherever required

def displayCart(): #displays the cart function
"""displayCart function - displays the items in the cart
---------------------------------------------------------------------"""
import os # Imports Operating System library to perform OS based operation
os.system('clear') # Clears the console screen
print("\n\nCart Contents:")
print("Your selected items:", cart)

def catMenu(): #function that displays the category menu
"""catMenu function - displays the categories user picks from
---------------------------------------------------------------------"""
import os
os.system('clear')
print("""
1 - Books
2 - Electronics
3 - Clothing
d - display cart contents
x - checkout
""") # Prints a menu with option numbers for user to select
category = input('\nSelect one of the categories or checkout:') # saves the user input in the category variable
return category # returns the category

def log_File(logfile,logrecord): #function that controls the log file
"""Function that appends the log activity.
------------------------------------------------------------------"""
log= open(logfile,"a") # opens the logfile in append mode
log.writelines(logrecord) # appends the logrecord at the end of the file
log.close() # closes the logfile
  
def itemDescription (category): #function that reads the category's file
"""Reads the category's text file that has the inventory items for the chosen
category and returns a list with the item descriptions and prices.
-----------------------------------------------------------------------------"""
import os
os.system('clear')
fi = open(category + '.txt',"r", encoding = "ISO-8859-1") # opens corresponding category file in read mode in given endcoding
itemfile = fi.readlines() # list of item descriptions and price
itemlist = []
for i in itemfile: # creates item list
if len(i) > 1:   
d = i.split(',') #splits the list at the comma
d[0] = d[0].strip() #Item name
d[1] = float(d[1].strip()) # Item price
d[2] = int(d[2].strip()) #Item quantity
itemlist.append(d) #adds to list
fi.close()
return itemlist # returns the read list of items

def itemMenu (category, itemList): #function that displays the items to choose from in menu form
"""itemMenu function - displays the menu of items
---------------------------------------------------------------------"""
import os
os.system('clear')   
print ('\n\n\t\t\t\t\t ' + category,'menu')
print('\n\t\t\t {0:3s} \t {1:26s} {2:8s}'.format('No.', 'Item Description', 'Price ')) # Prints the heading in given format
print('\t\t\t {0:3s} \t {1:26s} {2:8s}'
.format('===', '===========================', '========'))
  
for n in range(0, len(itemList)):
print('\t\t\t {0:2d} \t{1:26s} \t ${2:8.2f}'.format(n+1,itemList[n][0], itemList[n][1])) # formats and prints the list items
print('\t\t\t {0:2s} \tdisplay cart contents'.format("d"))
print('\t\t\t {0:2s} \tcheckout'.format("x"))
choice = input('\nSelect the ' + category + ' number or checkout:')
return choice # returns the choice given by user

def confirmAdd(itemList, category, cart): #Confirms item function
"""confirmAdd function - confirms the users selected item and adds the item to cart
---------------------------------------------------------------------"""
import os
os.system('clear')
confirm = input(" Would you like to add one " + itemList[category-1][0] + " (y/n?):")
if confirm == 'y':
found = False #if the item isn't added more than once
for d in cart:
if itemList[category-1][0] == d[0]:
found = True #if the item is added more than once add one to quantity
d[2] += 1 #increments quantity by 1 if multiple of same item is added to cart
break
if not found:
cart.append(itemList[category-1])
  
# Global code
book_list = itemDescription('books')
elect_list = itemDescription('electronics')
cloth_list = itemDescription('clothing')

date=str(datetime.datetime.now()) # stores the current time in date variable
lf= "IT109A9Log.txt" #log file where all information is stored

more_carts = 'y'   
carts = 0
total_items = 0   
total_cost = 0.0   

while more_carts == 'y':
cart = []
more_items = 'y'
while more_items == 'y':
category=catMenu() #Category function
if category == 'x':
more_items = 'n'
break
elif category == 'd':
displayCart() #Display cart function   
elif category not in '123':
print('Invalid category selected')
continue
if category == '1':
choice = 0
while choice != 'x':
choice = itemMenu('Book', book_list)
if choice == 'x':
continue
elif choice == 'd':
displayCart() #display cart function
elif int(choice) <= len(book_list):
confirm = confirmAdd(book_list,int(choice),cart) #Confirm for books
else:
print('Invalid item selected')
elif category == '2':
choice = 0
while choice != 'x':
choice = itemMenu('Electronics', elect_list)
if choice == 'x':
continue
elif choice == 'd':
displayCart() #display cart function
elif int(choice) <= len(elect_list):
confirm = confirmAdd(elect_list,int(choice),cart) #Confirm for elecs
else:
print('Invalid item selected')
elif category == '3':
choice = 0
while choice != 'x':
choice = itemMenu('Clothing', cloth_list)
if choice == 'x':
continue
elif choice == 'd':
displayCart() #display cart function
elif int(choice) <= len(cloth_list):
confirm = confirmAdd(cloth_list,int(choice),cart) #Confirm for clothing
else:
print('Invalid item selected')
if category == 'x':
print('\t\tCheckout selected')
displayCart()
cart_items, cart_cost = 0, 0.0
os.system('clear')
for item in cart:
cart_items += item[2] #quantity calculation
cart_cost += item[1] * item[2] #QTY * price
print('\nTotal number of items:', cart_items)
print('\nTotal cost of your items:${0:8.2f}'.format(cart_cost))
total_items += cart_items
total_cost += cart_cost
if cart_items > 0:
carts += 1
cartlog_list= ['\n\nDate: ' + date,
'\nType of log: Cart',
'\nCart Number: ' + str(carts),
'\nTotal number of items for the cart: ' + str(cart_items),
'\nTotal cost of items:${0:8.2f}'.format(cart_cost)]
log_File(lf,cartlog_list) #log of carts

more_carts = input('\nWould you like more carts(y/n)? ')

sessionLog_List= ['\n\nDate: ' + date,
'\nType of log: Session',
'\nNumber of carts: ' + str(carts),
'\nTotal number of items: '+ str(total_items),
'\nTotal cost of items:${0:8.2f}'.format(total_cost)]
log_File(lf,sessionLog_List) #log of session

#final output
os.system('clear')
print('\n\n\tTotal number of carts: ', carts)
print('\tTotal number of items: ', total_items)
print('\tTotal cost of items: ${0:8.2f}'.format(total_cost))

input('\n\nHit Enter to end program')