Hello i would like to override the user creation method, in order to verify if the email is used by another user or not:

class User(models.Model):
    _name = 'affichage2.user'
    _inherit = 'res.users'


    #this is the solution
    @api.model
    def create(self, values):

        res = super(User, self).create(vals)
        exis_email_id = self.env['res.users'].search([('email', '=', vals['email'].lower())])

if exis_email_id:
   raise osv.except_osv(_('Invalid Action!'), _('Email already exist.'))

return res

My solution don't working, any help please