old_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import api, fields, models, _
  
  
  class ResCompany(models.Model):
      _inherit = 'res.company'
  
      subcontracting_location_id = fields.Many2one('stock.location')
  
      @api.model
      def create_missing_subcontracting_location(self):
          company_without_subcontracting_loc = self.env['res.company'].search(
              [('subcontracting_location_id', '=', False)])
          company_without_subcontracting_loc._create_subcontracting_location()
  
      def _create_per_company_locations(self):
          super(ResCompany, self)._create_per_company_locations()
          self._create_subcontracting_location()
  
      def _create_subcontracting_location(self):
          parent_location = self.env.ref('stock.stock_location_locations_partner', raise_if_not_found=False)
          property_stock_subcontractor_res_partner_field = self.env['ir.model.fields'].search([
              ('model', '=', 'res.partner'),
              ('name', '=', 'property_stock_subcontractor')
          ])
          for company in self:
              subcontracting_location = self.env['stock.location'].create({
                  'name': _('Subcontracting Location'),
                  'usage': 'internal',
                  'location_id': parent_location.id,
                  'company_id': company.id,
              })
              self.env['ir.property'].create({
                  'name': 'property_stock_subcontractor_%s' % company.name,
                  'fields_id': property_stock_subcontractor_res_partner_field.id,
                  'company_id': company.id,
                  'value': 'stock.location,%d' % subcontracting_location.id,
              })
              company.subcontracting_location_id = subcontracting_location
  
new_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import api, fields, models, _
  
  
  class ResCompany(models.Model):
      _inherit = 'res.company'
  
      subcontracting_location_id = fields.Many2one('stock.location')
  
      @api.model
      def create_missing_subcontracting_location(self):
          company_without_subcontracting_loc = self.env['res.company'].search(
              [('subcontracting_location_id', '=', False)])
          company_without_subcontracting_loc._create_subcontracting_location()
  
      def _create_per_company_locations(self):
          super(ResCompany, self)._create_per_company_locations()
          self._create_subcontracting_location()
  
      def _create_subcontracting_location(self):
          parent_location = self.env.ref('stock.stock_location_locations', raise_if_not_found=False)
          property_stock_subcontractor_res_partner_field = self.env['ir.model.fields'].search([
              ('model', '=', 'res.partner'),
              ('name', '=', 'property_stock_subcontractor')
          ])
          for company in self:
              subcontracting_location = self.env['stock.location'].create({
                  'name': _('Subcontracting Location'),
                  'usage': 'internal',
                  'location_id': parent_location.id,
                  'company_id': company.id,
              })
              self.env['ir.property'].create({
                  'name': 'property_stock_subcontractor_%s' % company.name,
                  'fields_id': property_stock_subcontractor_res_partner_field.id,
                  'company_id': company.id,
                  'value': 'stock.location,%d' % subcontracting_location.id,
              })
              company.subcontracting_location_id = subcontracting_location
  
subject: Set subcontracting location a child of physical locations.