Hi, All

I am Using Odoo 11.0 C.E.

I Crated a new module 

Here is my Functions:

When I am trying to Upgrade the Module it shows me the following error:

 File "E:\odoo-11.0\addons\stock_br\models\stockpicking.py", line 20, in _amount_all
  File "E:\odoo-11.0\odoo\fields.py", line 945, in __get__
    record.ensure_one()
  File "E:\odoo-11.0\odoo\models.py", line 4267, in ensure_one
    raise ValueError("Expected singleton: %s" % self)
ValueError: Expected singleton: stock.picking(13, 3, 2, 1, 7, 6, 5, 4, 9, 8, 12, 11, 10, 14, 17, 16, 15, 19, 18, 20)

class StockMove(models.Model):
    _inherit = "stock.move"

    currency_id = fields.Many2one(related='picking_id.currency_id', store=True, string='Currency', readonly=True)
    price_total = fields.Monetary(compute='_compute_amount', string='Total', store=True)


    @api.depends('product_qty', 'price_unit')
    def _compute_amount(self):
        for line in self:
            total = 0.0
            total = line.product_qty * line.price_unit
        line.update({
            'price_total': total,
        })
   

class StockMoveLines(models.Model):
    _inherit = "stock.move.line"

    currency_id = fields.Many2one(related='picking_id.currency_id', store=True, string='Currency', readonly=True)
    price_unit = fields.Float(string='Unit Price', required=True, digits=dp.get_precision('Product Price'))
    price_total = fields.Monetary(compute='_compute_amount', string='Total', store=True)

class StockPicking(models.Model):
    _inherit = "stock.picking"

    currency_id = fields.Many2one('res.currency', 'Currency', readonly=True,default=lambda self: self.env.user.company_id.currency_id.id)
    amount_total = fields.Monetary(string='Total', store=True, readonly=True, compute='_amount_all')
    total_amount_in_words = fields.Char(string="Amount in Words", store=True, compute='_amount_all')


    @api.depends('move_lines.price_total')
    def _amount_all(self):
        for picking in self:
            amount_total = 0.0
            for line in picking.move_lines:
                amount_total += line.price_total

            lang = self.partner_id and self.partner_id.lang[:2]
            try:
                test = num2words(42, lang=lang)
            except NotImplementedError:
                lang = 'en'
            numword = num2words(amount_total , lang=lang)

          picking.update({
                'amount_total': amount_total,
                'total_amount_in_words': numword,
            })