I did a task module

class task(models.Model):
    _inherit = "project.task"

    def _default_task_accounting_type_id(self):
        domain = [('name', '=', 'Développement')]
        return self.env['account.analytic.tag'].search(domain, limit=1)

    task_accounting_type = fields.Many2one('account.analytic.tag', default=_default_task_accounting_type_id)

I want to have a different domain depending of task related project based on project name.
Something like:

    def _default_task_accounting_type_id(self):
         if self.project_id.???? == 'Marketing':
            domain = [('name', '=', 'Développement')]
         else:
            domain = [('name', '=', 'Développement')]
        return self.env['account.analytic.tag'].search(domain, limit=1)

How could I get the project name related to a task in my function?