blob: c1bdb5e752c695ea8251cff5b2c7584312a7d738 [file] [log] [blame]
:py:mod:`airflow.operators.python`
==================================
.. py:module:: airflow.operators.python
Module Contents
---------------
Classes
~~~~~~~
.. autoapisummary::
airflow.operators.python.PythonOperator
airflow.operators.python.BranchPythonOperator
airflow.operators.python.ShortCircuitOperator
airflow.operators.python.PythonVirtualenvOperator
Functions
~~~~~~~~~
.. autoapisummary::
airflow.operators.python.task
airflow.operators.python.get_current_context
.. py:function:: task(python_callable: Optional[Callable] = None, multiple_outputs: Optional[bool] = None, **kwargs)
Deprecated function that calls @task.python and allows users to turn a python function into
an Airflow task. Please use the following instead:
from airflow.decorators import task
@task
def my_task()
:param python_callable: A reference to an object that is callable
:type python_callable: python callable
:param op_kwargs: a dictionary of keyword arguments that will get unpacked
in your function (templated)
:type op_kwargs: dict
:param op_args: a list of positional arguments that will get unpacked when
calling your callable (templated)
:type op_args: list
:param multiple_outputs: if set, function return value will be
unrolled to multiple XCom values. Dict will unroll to xcom values with keys as keys.
Defaults to False.
:type multiple_outputs: bool
:return:
.. py:class:: PythonOperator(*, python_callable: Callable, op_args: Optional[Collection[Any]] = None, op_kwargs: Optional[Mapping[str, Any]] = None, templates_dict: Optional[Dict] = None, templates_exts: Optional[List[str]] = None, **kwargs)
Bases: :py:obj:`airflow.models.BaseOperator`
Executes a Python callable
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:PythonOperator`
When running your callable, Airflow will pass a set of keyword arguments that can be used in your
function. This set of kwargs correspond exactly to what you can use in your jinja templates.
For this to work, you need to define ``**kwargs`` in your function header, or you can add directly the
keyword arguments you would like to get - for example with the below code your callable will get
the values of ``ti`` and ``next_ds`` context variables.
With explicit arguments:
.. code-block:: python
def my_python_callable(ti, next_ds):
pass
With kwargs:
.. code-block:: python
def my_python_callable(**kwargs):
ti = kwargs["ti"]
next_ds = kwargs["next_ds"]
:param python_callable: A reference to an object that is callable
:type python_callable: python callable
:param op_kwargs: a dictionary of keyword arguments that will get unpacked
in your function
:type op_kwargs: dict (templated)
:param op_args: a list of positional arguments that will get unpacked when
calling your callable
:type op_args: list (templated)
:param templates_dict: a dictionary where the values are templates that
will get templated by the Airflow engine sometime between
``__init__`` and ``execute`` takes place and are made available
in your callable's context after the template has been applied. (templated)
:type templates_dict: dict[str]
:param templates_exts: a list of file extensions to resolve while
processing templated fields, for examples ``['.sql', '.hql']``
:type templates_exts: list[str]
.. py:attribute:: template_fields
:annotation: = ['templates_dict', 'op_args', 'op_kwargs']
.. py:attribute:: template_fields_renderers
.. py:attribute:: BLUE
:annotation: = #ffefeb
.. py:attribute:: ui_color
.. py:attribute:: shallow_copy_attrs
:annotation: = ['python_callable', 'op_kwargs']
.. py:method:: execute(self, context: Dict)
This is the main method to derive when creating an operator.
Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
.. py:method:: determine_kwargs(self, context: Mapping[str, Any]) -> Mapping[str, Any]
.. py:method:: execute_callable(self)
Calls the python callable with the given arguments.
:return: the return value of the call.
:rtype: any
.. py:class:: BranchPythonOperator(*, python_callable: Callable, op_args: Optional[Collection[Any]] = None, op_kwargs: Optional[Mapping[str, Any]] = None, templates_dict: Optional[Dict] = None, templates_exts: Optional[List[str]] = None, **kwargs)
Bases: :py:obj:`PythonOperator`, :py:obj:`airflow.models.skipmixin.SkipMixin`
Allows a workflow to "branch" or follow a path following the execution
of this task.
It derives the PythonOperator and expects a Python function that returns
a single task_id or list of task_ids to follow. The task_id(s) returned
should point to a task directly downstream from {self}. All other "branches"
or directly downstream tasks are marked with a state of ``skipped`` so that
these paths can't move forward. The ``skipped`` states are propagated
downstream to allow for the DAG state to fill up and the DAG run's state
to be inferred.
.. py:method:: execute(self, context: Dict)
This is the main method to derive when creating an operator.
Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
.. py:class:: ShortCircuitOperator(*, python_callable: Callable, op_args: Optional[Collection[Any]] = None, op_kwargs: Optional[Mapping[str, Any]] = None, templates_dict: Optional[Dict] = None, templates_exts: Optional[List[str]] = None, **kwargs)
Bases: :py:obj:`PythonOperator`, :py:obj:`airflow.models.skipmixin.SkipMixin`
Allows a workflow to continue only if a condition is met. Otherwise, the
workflow "short-circuits" and downstream tasks are skipped.
The ShortCircuitOperator is derived from the PythonOperator. It evaluates a
condition and short-circuits the workflow if the condition is False. Any
downstream tasks are marked with a state of "skipped". If the condition is
True, downstream tasks proceed as normal.
The condition is determined by the result of `python_callable`.
.. py:method:: execute(self, context: Dict)
This is the main method to derive when creating an operator.
Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
.. py:class:: PythonVirtualenvOperator(*, python_callable: Callable, requirements: Optional[Iterable[str]] = None, python_version: Optional[Union[str, int, float]] = None, use_dill: bool = False, system_site_packages: bool = True, op_args: Optional[Collection[Any]] = None, op_kwargs: Optional[Mapping[str, Any]] = None, string_args: Optional[Iterable[str]] = None, templates_dict: Optional[Dict] = None, templates_exts: Optional[List[str]] = None, **kwargs)
Bases: :py:obj:`PythonOperator`
Allows one to run a function in a virtualenv that is created and destroyed
automatically (with certain caveats).
The function must be defined using def, and not be
part of a class. All imports must happen inside the function
and no variables outside of the scope may be referenced. A global scope
variable named virtualenv_string_args will be available (populated by
string_args). In addition, one can pass stuff through op_args and op_kwargs, and one
can use a return value.
Note that if your virtualenv runs in a different Python major version than Airflow,
you cannot use return values, op_args, op_kwargs, or use any macros that are being provided to
Airflow through plugins. You can use string_args though.
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:PythonVirtualenvOperator`
:param python_callable: A python function with no references to outside variables,
defined with def, which will be run in a virtualenv
:type python_callable: function
:param requirements: A list of requirements as specified in a pip install command
:type requirements: list[str]
:param python_version: The Python version to run the virtualenv with. Note that
both 2 and 2.7 are acceptable forms.
:type python_version: Optional[Union[str, int, float]]
:param use_dill: Whether to use dill to serialize
the args and result (pickle is default). This allow more complex types
but requires you to include dill in your requirements.
:type use_dill: bool
:param system_site_packages: Whether to include
system_site_packages in your virtualenv.
See virtualenv documentation for more information.
:type system_site_packages: bool
:param op_args: A list of positional arguments to pass to python_callable.
:type op_args: list
:param op_kwargs: A dict of keyword arguments to pass to python_callable.
:type op_kwargs: dict
:param string_args: Strings that are present in the global var virtualenv_string_args,
available to python_callable at runtime as a list[str]. Note that args are split
by newline.
:type string_args: list[str]
:param templates_dict: a dictionary where the values are templates that
will get templated by the Airflow engine sometime between
``__init__`` and ``execute`` takes place and are made available
in your callable's context after the template has been applied
:type templates_dict: dict of str
:param templates_exts: a list of file extensions to resolve while
processing templated fields, for examples ``['.sql', '.hql']``
:type templates_exts: list[str]
.. py:attribute:: BASE_SERIALIZABLE_CONTEXT_KEYS
.. py:attribute:: PENDULUM_SERIALIZABLE_CONTEXT_KEYS
.. py:attribute:: AIRFLOW_SERIALIZABLE_CONTEXT_KEYS
.. py:method:: execute(self, context: airflow.utils.context.Context)
This is the main method to derive when creating an operator.
Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
.. py:method:: determine_kwargs(self, context: Mapping[str, Any]) -> Mapping[str, Any]
.. py:method:: execute_callable(self)
Calls the python callable with the given arguments.
:return: the return value of the call.
:rtype: any
.. py:method:: get_python_source(self)
Returns the source of self.python_callable
@return:
.. py:method:: __deepcopy__(self, memo)
Hack sorting double chained task lists by task_id to avoid hitting
max_depth on deepcopy operations.
.. py:function:: get_current_context() -> airflow.utils.context.Context
Obtain the execution context for the currently executing operator without
altering user method's signature.
This is the simplest method of retrieving the execution context dictionary.
**Old style:**
.. code:: python
def my_task(**context):
ti = context["ti"]
**New style:**
.. code:: python
from airflow.operators.python import get_current_context
def my_task():
context = get_current_context()
ti = context["ti"]
Current context will only have value if this method was called after an operator
was starting to execute.