kaxil commented on a change in pull request #14709: URL: https://github.com/apache/airflow/pull/14709#discussion_r593363124
########## File path: airflow/decorators/python.py ########## @@ -0,0 +1,104 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +from typing import Callable, Dict, Optional, TypeVar + +from airflow.decorators.base import BaseDecoratedOperator, task_decorator_factory +from airflow.exceptions import AirflowException +from airflow.utils.decorators import apply_defaults + +PYTHON_OPERATOR_UI_COLOR = '#ffefeb' + + +class _PythonDecoratedOperator(BaseDecoratedOperator): + """ + Wraps a Python callable and captures args/kwargs when called for execution. + + :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 + """ + + template_fields = ('op_args', 'op_kwargs') + template_fields_renderers = {"op_args": "py", "op_kwargs": "py"} + + ui_color = PYTHON_OPERATOR_UI_COLOR + + # since we won't mutate the arguments, we should just do the shallow copy + # there are some cases we can't deepcopy the objects (e.g protobuf). + shallow_copy_attrs = ('python_callable',) + + @apply_defaults + def __init__( + self, + **kwargs, + ) -> None: + super().__init__(**kwargs) + + def execute(self, context: Dict): + return_value = self.python_callable(*self.op_args, **self.op_kwargs) + self.log.debug("Done. Returned value was: %s", return_value) + if not self.multiple_outputs: + return return_value + if isinstance(return_value, dict): + for key in return_value.keys(): + if not isinstance(key, str): + raise AirflowException( + 'Returned dictionary keys must be strings when using ' + f'multiple_outputs, found {key} ({type(key)}) instead' + ) + for key, value in return_value.items(): + self.xcom_push(context, key, value) + else: + raise AirflowException( + f'Returned output was type {type(return_value)} expected dictionary ' 'for multiple_outputs' + ) + return return_value + + +T = TypeVar("T", bound=Callable) # pylint: disable=invalid-name + + +def python_task( + python_callable: Optional[Callable] = None, multiple_outputs: Optional[bool] = None, **kwargs +): + """ + Python operator decorator. Wraps a function into an Airflow operator. + Accepts kwargs for operator kwarg. Can be reused in a single DAG. + :param python_callable: Function to decorate Review comment: ```suggestion Accepts kwargs for operator kwarg. Can be reused in a single DAG. :param python_callable: Function to decorate ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
