why is there a problem with except

import sys

TICKET_PRICE = 10

tickets_remaining = 100

def calculate_price(TICKET_PRICE, number_of_tickets)

while tickets_remaining > 1:
    print("there are {} tickets left".format(tickets_remaining))

    name = input("what is your name?    ")

    number_of_tickets = int(input("how much tickets would you like, {}?    ".format(name)))
    try:
    except ValueError:
        print("oh no we ran into an issue. try again")
    else:
        amount_due = calculate_price(number_of_tickets)
        print("that would be ${}, {}.".format(amount_due, name))

        print("are you sure you want to go through with this?    ")

        confirm = input("do you want to proced? Y/N    ")
        while confirm.lower() not in ("y", "n"):
            print("whoops! try again!")
            confirm = input("do you want to proced? Y/N    ")

        if confirm == "y":
            print("SOLD!")
            tickets_remaining -= number_of_tickets
        elif confirm == "n":
            sys.exit("thanks anyways {}!".format(name))

print("out of tickets sorry!")