Sum selected records in one2many field odoo12

i Have the following models

class WorkStation(models.Model):

   _name = 'dlc.workstation'

   _description = 'list of work station'



production_ids = fields.One2many(comodel_name="dlc.pdetails", inverse_name="workstation_id", string="Production", required=False, )

sum_production = fields.Integer(string="Production total",  compute='_dlc_production', required=False,)




@api.one

@api.depends('production_ids.total', )

def _dlc_production(self):

   self.sum_production = sum(production.total for production in self.production_ids)

   """

   @api.depends() should contain all fields that will be used in the calculations.

   """

   pass

class ProductionData(models.Model):

   _name = 'dlc.pdata'

   _rec_name = 'start_date'

   _description = 'New Description'



name = fields.Char()

start_date = fields.Date(string="From", required=False, )

end_date = fields.Date(string="To", required=False,)

production_details_ids = fields.One2many(comodel_name="dlc.pdetails", inverse_name="production_data_id", string="Production Details"

class ProductionDetails(models.Model):

   _name = 'dlc.pdetails'

   _rec_name = 'workstation_id'



   workstation_id = fields.Many2one(comodel_name="dlc.workstation", string="DLC", required=False, )

   production_data_id = fields.Many2one(comodel_name="dlc.pdata", string="Production", required=False, )

   card_type = fields.Selection(string="Card Type",

                                selection=[('Temporary', 'Temporary'), ('Office Total', 'Office Total'),

                                           ('Permanent', 'Permanent')], required=False, )

   date = fields.Date(string="Date", required=False, related='production_data_id.start_date')
   total = fields.Integer(string="TOTAL", required=False, )

with this field sum_production gives me the total production figures per workstation but now i want total production for the last 7 days .

Just filter the production_ids list you use to sum.

from datetime import date


@api.one
@api.depends('production_ids.total', )
def _dlc_production(self):
   production_list = self.production_ids.filter(lambda r: r.date and (date.today() - timedelta(days=7)) <= r.date <= date.today())
   self.sum_production = sum(production.total for production in production_list)

Now if you want to have the total of the whole production

workstation_list = self.env['dlc.workstation'].search([])
production_list = workstation_list.mapped('production_ids').filter(lambda r: r.date and (date.today() - timedelta(days=7)) <= r.date <= date.today())