Task scheduling is essential for automating repetitive jobs like data backups, report generation, and notifications. Python offers multiple ways to schedule tasks, including schedule, APScheduler, Celery, and system-based schedulers like cron (Linux/Mac) or Task Scheduler (Windows).

---

Why Schedule Tasks?

Automate repetitive tasks
Run scripts at specific times (e.g., daily, weekly)
Improve efficiency and reduce manual workload
Schedule background jobs in web applications

---

1. Using schedule for Simple Task Scheduling

The schedule module allows running functions at a specific time.

Installation:

pip install schedule

Example: Run a Task Every 10 Seconds

import schedule
import time

def job():
    print("Task executed!")

# Schedule the job every 10 seconds
schedule.every(10).seconds.do(job)

while True:
    schedule.run_pending()
    time.sleep(1)

Now the task runs every 10 seconds automatically!

---

2. Scheduling Tasks at Specific Times

Run a Task Every Day at 9 AM

schedule.every().day.at("09:00").do(job)

Run a Task on Mondays

schedule.every().monday.at("08:00").do(job)

Run a Task Every Hour

schedule.every().hour.do(job)

Now the task executes at scheduled times!

---

3. Using APScheduler for Advanced Scheduling

APScheduler is more powerful and supports background jobs.

Installation:

pip install apscheduler

Example: Run a Job Every 5 Minutes

from apscheduler.schedulers.blocking import BlockingScheduler

def my_task():
    print("Task executed!")

scheduler = BlockingScheduler()
scheduler.add_job(my_task, 'interval', minutes=5)
scheduler.start()

Now the task runs every 5 minutes!

---

4. Using Celery for Distributed Task Scheduling

Celery is useful for handling background jobs in web applications.

Installation:

pip install celery

Example: Running a Background Task

from celery import Celery

app = Celery('tasks', broker='redis://localhost:6379/0')

@app.task
def my_task():
    print("Executing background task!")

Now Celery runs tasks asynchronously in the background!

---

5. Using cron (Linux/Mac) for Task Scheduling

cron allows running scripts at specific times.

Open crontab Editor:

crontab -e

Example: Run a Script Every Day at 7 AM

0 7 * * * /usr/bin/python3 /path/to/script.py

Now the Python script executes daily at 7 AM!

---

6. Using Windows Task Scheduler

On Windows, Task Scheduler can automate Python scripts.

Steps:

1️⃣ Open Task Scheduler → Click Create Basic Task
2️⃣ Set a trigger (e.g., daily, weekly)
3️⃣ Set the action → Start a Program
4️⃣ Browse and select python.exe
5️⃣ Add script path as an argument
6️⃣ Save and enable the task

Now the script runs automatically in Windows!