Pre-release code for the auction thingy

pr2019.py

### Initialisation
### - Input number of items
### - Set up all arrays for all tasks
###   - item numbers
###   - description
###   - reserve
###   - number of bids
###   - highest bid

TESTING = False

if TESTING:
    N = 4
    ItemNumber  = [0, 5361, 1359, 4141, 1901]
    Description = ["", "Car", "Sofa", "Book", "Television"]
    Reserve     = [0.0, 4500.00, 142.50, 8.75, 399.00]
    NumBids     = [0, 3, 0, 13, 5]
    HighBid     = [0.0, 2210.00, 0.00, 19.50, 380.00]
else:
    N = int(input("How many items in this auction? "))
    ItemNumber  = [0]   * (N+1)
    Description = [""]  * (N+1)
    Reserve     = [0.0] * (N+1)
    NumBids     = [0]   * (N+1)
    HighBid     = [0.0] * (N+1)
    


### Task 1
### - Enter each item number, description, reserve price.
###   - function to set index i
###   - return true if set, false if invalid

# We prompt the user for item number, description, reserve price. 
# If valid, we _set_ the arrays index i, and return True.
# If invalid, we print an error message and return False.
def input_item(i):
    print("")
    print("Accepting information for item", i, "of", N)
    item_num =  int(input("  * Item number: "))
    if item_num <= 0:
        print("---------- Error: item number must be positive")
        return False
    if item_num in ItemNumber:
        print("---------- Error: item number already used")
        return False
    description =   input("  * Description: ")
    if description == "":
        print("---------- Error: description can't be empty")
        return False
    reserve = float(input("  * Reserve:     "))
    if reserve <= 0:
        print("---------- Error: reserve must be positive")
        return False
    # If we get this far, there was no error.
    # Store the data collected in the arrays.
    ItemNumber[i]  = item_num
    Description[i] = description
    Reserve[i]     = reserve
    NumBids[i]     = 0
    HighBid[i]     = 0.0
    return True


def task1():
    i = 1
    while i <= N:
        if input_item(i) == True:
            # Item was valid, so go on to next item.
            i = i + 1
        else:
            # Item was invalid, so do this item again.
            pass


### Task 2
### - Press V to view items or B to bid or Q to quit
### - if V then view_items()
###   - just display summary of all items
### - if B then bid()
###   - enter buyer number (which we ignore)
###   - enter item number
###   - enter bid amount
###   - record bid if it's high enough; reject otherwise

def view_items():
    print("")
    print("Items on sale:")
    print("")
    for i in range(1,N+1):
        print("  Item:", ItemNumber[i], "    Bid:", HighBid[i], "    ", Description[i])

# Return True if a valid bid was made; False otherwise.
def bid():
    print("Enter the following information to make a bid:")
    buyer_num =   int(input("  * Buyer number: "))
    if buyer_num < 0:
        print("---------- Error: buyer number must be positive")
        return False
    item_num  =   int(input("  * Item number:  "))
    try:
        item_idx = ItemNumber.index(item_num)
    except ValueError:
        print("---------- Error: item number", item_num, "does not exist")
        return False
    bid       = float(input("  * Bid ($):      "))
    if bid <= HighBid[item_idx]:
        print("---------- Error: bid too low")
        return False
    # If we get this far, we have a valid bid.
    # Update the arrays.
    NumBids[item_idx] = NumBids[item_idx] + 1
    HighBid[item_idx] = bid
    print("Thank you; your bid has been entered.")
    return True

def task2():
    while True:
        print("")
        print("[V] View items      [B] Bid       [Q] Quit")
        choice = input("> ")
        if choice == "V":
            view_items()
        elif choice == "B":
            bid()
        elif choice == "Q":
            print("Thanks for all your bids.")
            return
        else:
            print("Invalid choice; try again.")


### Task 3
### - calculate and display total fee from sold items
### - display item # and final bid for unsold items
### - display item # of items that received no bids
### - display the count of each of the above three categories
### * variables: num_sold, num_unsold, num_unbid, total_fee
### * run through items three times to display info and update counts
### * display totals

def task3():
    total_fee  = 0.0
    num_sold   = 0
    num_unsold = 0
    num_unbid  = 0

    print("")
    for i in range(1,N+1):
        if HighBid[i] >= Reserve[i]:
            # It sold.
            num_sold = num_sold + 1
            total_fee = total_fee + (0.1 * HighBid[i])
    print("Number of items sold:", num_sold)
    print("Total fee ($):       ", total_fee)

    print("")
    print("Unsold items (and highest bid):")
    for i in range(1,N+1):
        if HighBid[i] < Reserve[i] and NumBids[i] > 0:
            print("  ", ItemNumber[i], "($" + str(HighBid[i]) + ")")
            num_unsold = num_unsold + 1

    print("")
    print("Items with no bids:")
    for i in range(1,N+1):
        if NumBids[i] == 0:
            print("  ", ItemNumber[i])
            num_unbid = num_unbid + 1

    print("")
    print("Summary")
    print("  Items sold:  ", num_sold)
    print("  Items unsold:", num_unsold)
    print("  Items unbid: ", num_unbid)


task1()
task2()
task3()