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

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r"""
A tutorial example take you to experience pydolphinscheduler.

After tutorial.py file submit to Apache DolphinScheduler server a DAG would be create,
and workflow DAG graph as below:

                  --> task_child_one
                /                    \
task_parent -->                        -->  task_union
                \                    /
                  --> task_child_two

it will instantiate and run all the task it have.
"""

# [start tutorial]
# [start package_import]
# Import ProcessDefinition object to define your workflow attributes
from pydolphinscheduler.core.process_definition import ProcessDefinition

# Import task Shell object cause we would create some shell tasks later
from pydolphinscheduler.tasks.shell import Shell

# [end package_import]

# [start workflow_declare]
with ProcessDefinition(
    name="tutorial",
    schedule="0 0 0 * * ? *",
    start_time="2021-01-01",
    tenant="tenant_exists",
) as pd:
    # [end workflow_declare]
    # [start task_declare]
    task_parent = Shell(name="task_parent", command="echo hello pydolphinscheduler")
    task_child_one = Shell(name="task_child_one", command="echo 'child one'")
    task_child_two = Shell(name="task_child_two", command="echo 'child two'")
    task_union = Shell(name="task_union", command="echo union")
    # [end task_declare]

    # [start task_relation_declare]
    task_group = [task_child_one, task_child_two]
    task_parent.set_downstream(task_group)

    task_union << task_group
    # [end task_relation_declare]

    # [start submit_or_run]
    pd.run()
    # [end submit_or_run]
# [end tutorial]