example_02.py

from datetime import datetime

from airflow import DAG
from airflow.operators.dummy import DummyOperator
from airflow.operators.bash import BashOperator
from airflow.operators.python import PythonOperator
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults



with DAG(
    dag_id='example_dag_02',
    start_date=datetime(2024,10,16),
    schedule_interval='@daily'
) as dag:

    start = DummyOperator(task_id='start')
    end = DummyOperator(task_id='end')


    bash_task = BashOperator(
        task_id='run_bash_command',
        bash_command='echo "Hello, Airflow (bash)"'
    )


    def print_string():
        print("Hello, Airflow (python)")


    python_task = PythonOperator(
        task_id='run_python_function',
        python_callable=print_string
    )

    class CustomOperator(BaseOperator):
        @apply_defaults
        def __init__(self, param, *args, **kwargs):
            super(CustomOperator, self).__init__(*args, **kwargs)
            self.param = param
            
        def execute(self, context):
            print(f"Custom Operator : {param}")



    custom_task = CustomOperator(
        task_id='run_custom_task',
        param="Hello, Airflow (custom)"
    )


    start >> bash_task >> python_task >> custom_task >> end