I am trying to edit a existing module to add a auto generated sequence in the field in it. I found adding a _default for that field might help, but when did I ended up in error please help, thank you.

This code is from "product.py"

    _name = "product.product"
    _description = "Product"
    _table = "product_product"
    _inherits = {'product.template': 'product_tmpl_id'}
    _inherit = ['mail.thread']
    _order = 'default_code,name_template'
    _columns = {
        'qty_available': fields.function(_product_qty_available, type='float', string='Quantity On Hand'),
        'virtual_available': fields.function(_product_virtual_available, type='float', string='Quantity Available'),
        'incoming_qty': fields.function(_product_incoming_qty, type='float', string='Incoming'),
        'outgoing_qty': fields.function(_product_outgoing_qty, type='float', string='Outgoing'),
        'price': fields.function(_product_price, type='float', string='Price', digits_compute=dp.get_precision('Product Price')),
        'lst_price' : fields.function(_product_lst_price, type='float', string='Public Price', digits_compute=dp.get_precision('Product Price')),
        'code': fields.function(_product_code, type='char', string='Internal Reference'),
        'partner_ref' : fields.function(_product_partner_ref, type='char', string='Customer ref'),
        'default_code' : fields.char('Internal Reference', size=64, select=True),
        'active': fields.boolean('Active', help="If unchecked, it will allow you to hide the product without removing it."),
        'variants': fields.char('Variants', size=64),
        'product_tmpl_id': fields.many2one('product.template', 'Product Template', required=True, ondelete="cascade", select=True),
        'ean13': fields.char('EAN13 Barcode', size=13, help="International Article Number used for product identification."),
        'packaging' : fields.one2many('product.packaging', 'product_id', 'Logistical Units', help="Gives the different ways to package the same product. This has no impact on the picking order and is mainly used if you use the EDI module."),
        'price_extra': fields.float('Variant Price Extra', digits_compute=dp.get_precision('Product Price')),
        'price_margin': fields.float('Variant Price Margin', digits_compute=dp.get_precision('Product Price')),
        'pricelist_id': fields.dummy(string='Pricelist', relation='product.pricelist', type='many2one'),
        'name_template': fields.related('product_tmpl_id', 'name', string="Template Name", type='char', size=128, store=True, select=True),
        'color': fields.integer('Color Index'),
        # image: all image fields are base64 encoded and PIL-supported
        'image': fields.binary("Image",
            help="This field holds the image used as image for the product, limited to 1024x1024px."),
        'image_medium': fields.function(_get_image, fnct_inv=_set_image,
            string="Medium-sized image", type="binary", multi="_get_image",
            store={
                'product.product': (lambda self, cr, uid, ids, c={}: ids, ['image'], 10),
            },
            help="Medium-sized image of the product. It is automatically "\
                 "resized as a 128x128px image, with aspect ratio preserved, "\
                 "only when the image exceeds one of those sizes. Use this field in form views or some kanban views."),
        'image_small': fields.function(_get_image, fnct_inv=_set_image,
            string="Small-sized image", type="binary", multi="_get_image",
            store={
                'product.product': (lambda self, cr, uid, ids, c={}: ids, ['image'], 10),
            },
            help="Small-sized image of the product. It is automatically "\
                 "resized as a 64x64px image, with aspect ratio preserved. "\
                 "Use this field anywhere a small image is required."),
        'seller_info_id': fields.function(_calc_seller, type='many2one', relation="product.supplierinfo", string="Supplier Info", multi="seller_info"),
        'seller_delay': fields.function(_calc_seller, type='integer', string='Supplier Lead Time', multi="seller_info", help="This is the average delay in days between the purchase order confirmation and the reception of goods for this product and for the default supplier. It is used by the scheduler to order requests based on reordering delays."),
        'seller_qty': fields.function(_calc_seller, type='float', string='Supplier Quantity', multi="seller_info", help="This is minimum quantity to purchase from Main Supplier."),
        'seller_id': fields.function(_calc_seller, type='many2one', relation="res.partner", string='Main Supplier', help="Main Supplier who has highest priority in Supplier List.", multi="seller_info"),
    }

This is the default function im trying to add for the field "default_code"
#_defaults = { 'default_code': lambda self,cr,uid,context={}: self.pool.get(‘ir.sequence’).get(cr, uid, ‘product.product’), }