🚀原文地址：https://airflow.apache.org/docs/apache-airflow/stable/macros-ref.html

Variables and macros can be used in templates (see the Jinja Templating section)

The following come for free out of the box with Airflow. Additional custom macros can be added globally through Plugins, or at a DAG level through the DAG.user_defined_macros argument.

1. Default Variables

The Airflow engine passes a few variables by default that are accessible in all templates

Variable Description
{{ ds }} the execution date as YYYY-MM-DD
{{ ds_nodash }} the execution date as YYYYMMDD
{{ prev_ds }} the previous execution date as YYYY-MM-DD if {{ ds }} is 2018-01-08 and schedule_interval is @weekly, {{ prev_ds }} will be 2018-01-01
{{ prev_ds_nodash }} the previous execution date as YYYYMMDD if exists, else None
{{ next_ds }} the next execution date as YYYY-MM-DD if {{ ds }} is 2018-01-01 and schedule_interval is @weekly, {{ next_ds }} will be 2018-01-08
{{ next_ds_nodash }} the next execution date as YYYYMMDD if exists, else None
{{ yesterday_ds }} the day before the execution date as YYYY-MM-DD
{{ yesterday_ds_nodash }} the day before the execution date as YYYYMMDD
{{ tomorrow_ds }} the day after the execution date as YYYY-MM-DD
{{ tomorrow_ds_nodash }} the day after the execution date as YYYYMMDD
{{ ts }} same as execution_date.isoformat(). Example: 2018-01-01T00:00:00+00:00
{{ ts_nodash }} same as ts without -, : and TimeZone info. Example: 20180101T000000
{{ ts_nodash_with_tz }} same as ts without - and :. Example: 20180101T000000+0000
{{ execution_date }} the execution_date (logical date) (pendulum.Pendulum)
{{ prev_execution_date }} the previous execution date (if available) (pendulum.Pendulum)
{{ prev_execution_date_success }} execution date from prior successful dag run (if available) (pendulum.Pendulum)
{{ prev_start_date_success }} start date from prior successful dag run (if available) (pendulum.Pendulum)
{{ next_execution_date }} the next execution date (pendulum.Pendulum)
{{ dag }} the DAG object
{{ task }} the Task object
{{ macros }} a reference to the macros package, described below
{{ task_instance }} the task_instance object
{{ ti }} ⭐same as {{ task_instance }}
{{ params }} a reference to the user-defined params dictionary which can be overridden by the dictionary passed through trigger_dag -c if you enabled dag_run_conf_overrides_params in airflow.cfg
{{ var.value.my_var }} global defined variables represented as a dictionary
{{ var.json.my_var.path }} global defined variables represented as a dictionary with deserialized JSON object, append the path to the key within the JSON object
{{ task_instance_key_str }} a unique, human-readable key to the task instance formatted {dag_id}__{task_id}__{ds_nodash}
{{ conf }} the full configuration object located at airflow.configuration.conf which represents the content of your airflow.cfg
{{ run_id }} the run_id of the current DAG run
{{ dag_run }} a reference to the DagRun object
{{ test_mode }} whether the task instance was called using the CLI’s test subcommand

Note that you can access the object’s attributes and methods with simple dot notation. Here are some examples of what is possible: {{ task.owner }}, {{ task.task_id }}, {{ ti.hostname }}, … Refer to the models documentation for more information on the objects’ attributes and methods.

The var template variable allows you to access variables defined in Airflow’s UI. You can access them as either plain-text or JSON. If you use JSON, you are also able to walk nested structures, such as dictionaries like: {{ var.json.my_dict_var.key1 }}.

It is also possible to fetch a variable by string if needed with {{ var.value.get('my.var', 'fallback') }} or {{ var.json.get('my.dict.var', {'key1': 'val1'}) }}. Defaults can be supplied in case the variable does not exist.

2. Macros

Macros are a way to expose objects to your templates and live under the macros namespace in your templates.

A few commonly used libraries and methods are made available.

Variable Description
macros.datetime The standard lib’s datetime.datetime
macros.timedelta The standard lib’s datetime.timedelta
macros.dateutil A reference to the dateutil package
macros.time The standard lib’s datetime.time
macros.uuid The standard lib’s uuid
macros.random The standard lib’s random

2.1 Common functions

  • airflow.macros.datetime_diff_for_humans(dt, since=None)
  • airflow.macros.ds_add(ds, days)
  • airflow.macros.random()
  • airflow.macros.hive.closest_ds_partition
  • airflow.macros.hive.max_partition