'Returns True if ticket has already placed orders.
Else False.'

def has_completed_order_tickets(self):

    order_tickets = OrderTicket.query.filter_by(ticket_id=self.id)
    count = 0
    for order_ticket in order_tickets:
        order = Order.query.filter_by(id=order_ticket.order_id).first()
        if ((order.status == 'completed') or (order.status == 'placed')):
            count += 1
    return bool((count > 0))
