The sched2 module extends the general purpose event scheduler sched from Python's standard library. sched2.scheduler is a subclass of sched.scheduler that adds new features such as the every and cron decorators. It's a practical tool for automating tasks that need to run repeatedly after certain time delays or at specific times.

Install

sched2 is available on PyPI.

pip install sched2

Examples

The code below uses the every decorator to schedule checking the public IP address every two minutes. Then every day at 9:00, the cron decorator is used to send a report via email. Finally, the on decorator is used to send an email when the IP address changes.

from smtplib import SMTP_SSL
from urllib.request import urlopen

from sched2 import scheduler

# Create a scheduler
sc = scheduler()

# we'll use this to remember the last IP address between runs
last_ip = None


@sc.every(30)  # Run every two minutes
def print_ip_address():
    global last_ip

    ip = urlopen("https://icanhazip.com/").read().decode("utf-8").strip()

    print(f"Public IP address: {ip}")

    last_ip = last_ip or ip  # reset last_ip
    if ip != last_ip:
        last_ip = ip

        # Emit an event when the IP address changes
        sc.emit("ip_changed", kwargs={"new_ip": ip})


@sc.cron("0 9 * * 1-5")  # Run every weekday at 9:00
def send_report():
    sendmail("Daily Report", "The numbers are up!")


@sc.on("ip_changed")  # Run when 'ip_changed' event is emitted
def send_email(new_ip):
    sendmail("IP Address Changed", f"New IP address: {ip}")


def sendmail(subject, body):
    """Send an email using SMTP_SSL."""
    with SMTP_SSL("smtp.example.com") as smtp:
        smtp.login("me@example.com", "password")
        smtp.sendmail(
            "me@example.com",
            "team@example.com",
            f"{subject}\n\n{body}",
        )


# Run the scheduler
sc.run()

Source Code and Issues

The source code for sched2 is available on GitHub at github.com/medecau/sched2.

You can help improve sched2 by reporting any issues or suggestions on the issue tracker at github.com/medecau/sched2/issues.