Cleaning Up Code

TICKET_PRICE = 10

tickets_remaining = 100  

while tickets_remaining > 0:
    print("There are {} tickets remaining.".format(tickets_remaining))

    try:
        name = input("Welcome to MasterTicket! What's your name?  ")
        if "discount" in name:
            raise ValueError("Sorry, there aren't any discounts at this time")
        else:
            ticket_request = input("Hello, {}! How many tickets would you like?\n"
                               "Remember, every ticket is ${}.  ".format(name, TICKET_PRICE))
            if "discount" in ticket_request:
                raise ValueError("Sorry, there aren't any discounts at this time")
            else:
                ticket_request = int(ticket_request)
                if ticket_request > tickets_remaining:
                    raise ValueError("There are only {} tickets remaining".format(tickets_remaining))
                elif ticket_request <= 0:
                    raise ValueError("You must request at least one ticket")
    except ValueError as err:
        if "base 10" in str(err):
            print("Sorry, that's not a valid number. Please try again.") 
        else:
            print("{}. Please try again.".format(err))
    else:
        price = ticket_request * TICKET_PRICE

        print("Your total is ${}.".format(price))

        confirm_purchase = input("Please confirm your order.\n"
                                 "(Enter Y/N)  ")

        is_confirmed = confirm_purchase.upper() == "Y" or confirm_purchase.upper() == "YES"
        is_not_confirmed = confirm_purchase.upper() == "N" or confirm_purchase.upper() == "NO"

        while not is_confirmed and not is_not_confirmed:
            confirm_purchase = input("Please enter a valid input to confirm your purchase.  ")
            if confirm_purchase.upper() == "Y" or confirm_purchase.upper() == "YES":
                is_confirmed = True
            elif confirm_purchase.upper() == "N" or confirm_purchase.upper() == "NO":
                is_not_confirmed = True
        else:
            if is_confirmed:
                print("Sold!")
                tickets_remaining -= ticket_request
            else:    
                print("Thanks for stopping by, {}!".format(name))

else:
    print("Sorry, there are no more tickets available!")