I wanted to show the number of days (0 day, -2 days, 3 days etc) for the Integer field "Days Left". 

Assuming today date is 09-06-2025(DD-MM-YYYY), this is how the result is showing up in the view. The problem here is that the result is empty(not showing up) when the dates difference is equal to 0 Day. 

Product Name-----Expiry Date-----Days Left

Product 1 ---------07-06-2025------    -2

Product 2 --------09-06-2025 ------  (empty)

Product 3 ---------12-06-2025 -------   3

Compute function for "Days Left"

class Drug(models.Model):
    _inherit = "product.template"

    expiry_date = fields.Date(string="Expiry Date")
    due = fields.Integer(string="Days Left", compute="_compute_due")

def _compute_due(self):
    for record in self:
        if record.expiry_date:
            fmt = '%Y-%m-%d'
            from_date = record.expiry_date.strftime(fmt)
            today_date = date.today()
            if today_date == record.expiry_date:
                record.due = 0
            else:
                now = today_date.strftime(fmt)
                d1 = datetime.strptime(from_date, fmt)
                d2 = datetime.strptime(now, fmt)
                print(from_date, today_date, now, d1, d2)
                record.due = str((d1 - d2).days)
        else:
            record.due = ""

Thank you for your suggestion!