Source code for airflow.operators.branch

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"""Branching operators."""

from __future__ import annotations

from typing import TYPE_CHECKING, Iterable

from airflow.models.baseoperator import BaseOperator
from airflow.models.skipmixin import SkipMixin

    from airflow.utils.context import Context

[docs]class BranchMixIn(SkipMixin): """Utility helper which handles the branching as one-liner."""
[docs] def do_branch(self, context: Context, branches_to_execute: str | Iterable[str]) -> str | Iterable[str]: """Implement the handling of branching including logging.""""Branch into %s", branches_to_execute) self.skip_all_except(context["ti"], branches_to_execute) return branches_to_execute
[docs]class BaseBranchOperator(BaseOperator, BranchMixIn): """ A base class for creating operators with branching functionality, like to BranchPythonOperator. Users should create a subclass from this operator and implement the function `choose_branch(self, context)`. This should run whatever business logic is needed to determine the branch, and return either the task_id for a single task (as a str) or a list of task_ids. The operator will continue with the returned task_id(s), and all other tasks directly downstream of this operator will be skipped. """
[docs] def choose_branch(self, context: Context) -> str | Iterable[str]: """ Abstract method to choose which branch to run. Subclasses should implement this, running whatever logic is necessary to choose a branch and returning a task_id or list of task_ids. :param context: Context dictionary as passed to execute() """ raise NotImplementedError
[docs] def execute(self, context: Context): return self.do_branch(context, self.choose_branch(context))

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