reminder.py

import time
import sys

import sched
from pync import Notifier

def main():
    seconds = int(sys.argv[1]) * 60
    text = sys.argv[2]

    Notifier.notify(text, title="Reminder", sound="default")

    s = sched.scheduler(time.time, time.sleep)

    s.enter(seconds, 1, showNotifier, ())
    s.run()

if __name__ == '__main__':
    if len(sys.argv) < 3:
        raise ValueError("Two positional arguments required")

    main()