:mod:`airflow.sensors.external_task_sensor`
===========================================

.. py:module:: airflow.sensors.external_task_sensor







Module Contents
---------------






.. py:class:: ExternalTaskSensor(external_dag_id, external_task_id, allowed_states=None, execution_delta=None, execution_date_fn=None, check_existence=False, *args, **kwargs)

   Bases::class:`airflow.sensors.base_sensor_operator.BaseSensorOperator`

   

   Waits for a different DAG or a task in a different DAG to complete for a
   specific execution_date

   :param external_dag_id: The dag_id that contains the task you want to
       wait for
   :type external_dag_id: str
   :param external_task_id: The task_id that contains the task you want to
       wait for. If ``None`` the sensor waits for the DAG
   :type external_task_id: str
   :param allowed_states: list of allowed states, default is ``['success']``
   :type allowed_states: list
   :param execution_delta: time difference with the previous execution to
       look at, the default is the same execution_date as the current task or DAG.
       For yesterday, use [positive!] datetime.timedelta(days=1). Either
       execution_delta or execution_date_fn can be passed to
       ExternalTaskSensor, but not both.
   :type execution_delta: datetime.timedelta
   :param execution_date_fn: function that receives the current execution date
       and returns the desired execution dates to query. Either execution_delta
       or execution_date_fn can be passed to ExternalTaskSensor, but not both.
   :type execution_date_fn: callable
   :param check_existence: Set to `True` to check if the external task exists (when
       external_task_id is not None) or check if the DAG to wait for exists (when
       external_task_id is None), and immediately cease waiting if the external task
       or DAG does not exist (default value: False).
   :type check_existence: bool


   

   

   .. attribute:: template_fields
      :annotation: = ['external_dag_id', 'external_task_id'] 

      



   

   

   .. attribute:: ui_color
      :annotation: = #19647e 

      



   

   

   

   .. method:: poke(self, context, session=None)