DolphinScheduler/dolphinscheduler-python/pydolphinscheduler/examples/task_switch_example.py

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r"""
A example workflow for task switch.

This example will create four task in single workflow, with three shell task and one switch task. Task switch
have one upstream which we declare explicit with syntax `parent >> switch`, and two downstream automatically
set dependence by switch task by passing parameter `condition`. The graph of this workflow like:
                      --> switch_child_1
                    /
parent -> switch ->
                    \
                      --> switch_child_2
.
"""

from pydolphinscheduler.core.process_definition import ProcessDefinition
from pydolphinscheduler.tasks.shell import Shell
from pydolphinscheduler.tasks.switch import Branch, Default, Switch, SwitchCondition

with ProcessDefinition(
    name="task_switch_example",
    tenant="tenant_exists",
    param=[
        {
            "prop": "var",
            "direct": "IN",
            "type": "VARCHAR",
            "value": "1"
        }
    ]
) as pd:
    parent = Shell(name="parent", command="echo parent")
    switch_child_1 = Shell(name="switch_child_1", command="echo switch_child_1")
    switch_child_2 = Shell(name="switch_child_2", command="echo switch_child_2")
    switch_condition = SwitchCondition(
        Branch(condition="${var} > 1", task=switch_child_1),
        Default(task=switch_child_2),
    )

    switch = Switch(name="switch", condition=switch_condition)
    parent >> switch
    pd.submit()