Source code for airflow.models.taskmixin

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from abc import abstractmethod
from typing import Sequence, Union


[docs]class TaskMixin: """ 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] def roots(self): """Should return list of root operator List[BaseOperator]""" raise NotImplementedError()
@property
[docs] def leaves(self): """Should return list of leaf operator List[BaseOperator]""" raise NotImplementedError()
@abstractmethod
[docs] def set_upstream(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Set a task or a task list to be directly upstream from the current task.""" raise NotImplementedError()
@abstractmethod
[docs] def set_downstream(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Set a task or a task list to be directly downstream from the current task.""" raise NotImplementedError()
[docs] def update_relative(self, other: "TaskMixin", upstream=True) -> None:
""" Update relationship information about another TaskMixin. Default is no-op. Override if necessary. """
[docs] def __lshift__(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Implements Task << Task""" self.set_upstream(other) return other
[docs] def __rshift__(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Implements Task >> Task""" self.set_downstream(other) return other
[docs] def __rrshift__(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Called for Task >> [Task] because list don't have __rshift__ operators.""" self.__lshift__(other) return self
[docs] def __rlshift__(self, other: Union["TaskMixin", Sequence["TaskMixin"]]): """Called for Task << [Task] because list don't have __lshift__ operators.""" self.__rshift__(other) return self

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