# 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.fromabcimportabstractmethodfromtypingimportSequence,Union
[docs]classTaskMixin:""" Mixing implementing common chain methods like >> and <<. In the following functions we use: Task = Union[BaseOperator, XComArg] No type annotations due to cyclic imports. """@property
[docs]defroots(self):"""Should return list of root operator List[BaseOperator]"""raiseNotImplementedError()
@property
[docs]defleaves(self):"""Should return list of leaf operator List[BaseOperator]"""raiseNotImplementedError()
@abstractmethod
[docs]defset_upstream(self,other:Union["TaskMixin",Sequence["TaskMixin"]]):"""Set a task or a task list to be directly upstream from the current task."""raiseNotImplementedError()
@abstractmethod
[docs]defset_downstream(self,other:Union["TaskMixin",Sequence["TaskMixin"]]):"""Set a task or a task list to be directly downstream from the current task."""raiseNotImplementedError()
[docs]def__rrshift__(self,other:Union["TaskMixin",Sequence["TaskMixin"]]):"""Called for Task >> [Task] because list don't have __rshift__ operators."""self.__lshift__(other)returnself
[docs]def__rlshift__(self,other:Union["TaskMixin",Sequence["TaskMixin"]]):"""Called for Task << [Task] because list don't have __lshift__ operators."""self.__rshift__(other)returnself