## Overview
Dagline is a package for executing multiple tasks of a DAG flow in parallel. The type of task can be python function and Windows bat script.
### System Requirements
* Python 3.10+
### Installation
* python -m pip install dagline
### Use-cases
* **Create a folder where you put the dag files locally. You can name your folder/py whatever you want:**
dags\\
└──dag\_example.py
* **Define the DAG, open** _**dag\_example.py**_ **and enter the following content:**
```python
from dagline.models.dag import DAG
from dagline.models.operators.winbat import WinbatOperator
from dagline.models.operators.python import PythonOperator
def read_excel():
'''Do your works here'''
print('call this func read_excel')
def read_csv():
'''Do your works here'''
print('call this func read_csv')
def load_to_db():
'''Do your works here'''
print('call this func load_to_db')
task1 = PythonOperator(task_id = 'read_excel', python_callable = read_excel)
task2 = PythonOperator(task_id = 'read_csv', python_callable = read_csv)
task3 = PythonOperator(task_id = 'load_to_db', python_callable = load_to_db)
task4 = WinbatOperator(task_id = 'housekeep', bat_command = r"C:\xxx\housekeep.bat")
'''DAG graph, child task : [parent tasks]'''
tasks_flow ={
task1 : [],
task2 : [],
task3 : [task1, task2],
task4 : [task3]
}
with DAG(
dag_id = 'dag_example',
tasks_flow = tasks_flow,
logfile = "C:\xxx\dag_example.log"
) as dag:
pass
```
* **Run a DAG in parallel or run a DAG from some specified tasks**
_python -m dagline dags run \<dag\_files\_home> \<dag\_id> \< --start\_with\_task\_ids >_
dag\_files\_home The folder of the DAG files
dag\_id The id of the dag
--start\_with\_task\_ids A list of the task ids, if it was provided, the DAG will start from these tasks, not from the beginning of the DAG
```python
>python -m dagline dags run C:\xxx\dags_tasks\dags dag_example1
>python -m dagline dags run C:\xxx\dags_tasks\dags dag_example1 --start_with_task_ids read_csv
```
* **Run a task of the DAG**
_python -m dagline tasks run \<dag\_files\_home> \<dag\_id> \<task\_id>_
dag\_files\_home The folder of the DAG files
dag\_id The id of the dag
task\_id The id of the task, only runs this task in the DAG
```python
>python -m dagline tasks run C:\xxx\dags_tasks\dags dag_example read_csv
```
* **Visualize a DAG on the html page**
_python -m dagline dags show \<dag\_files\_home> \<dag\_id>_
dag\_files\_home The folder of the DAG files
dag\_id The id of the dag
```python
>python -m dagline dags show C:\xxx\dags_tasks\dags dag_example
```
