friendly reminders on Linux

remind_me.py

#!/usr/bin/env python3
# 
# alias remind-me="$HOME/bin/remind_me.py"

from sys import argv, exit, stderr
import subprocess
import time

USAGE_STRING = """
usage: remind-me @time "your message goes here"
"""
try:
    from gi.repository import Notify
except ImportError:
    print("""
Library gi.repository not found. Install PyGObject for your distro from here:
  https://wiki.gnome.org/action/show/Projects/PyGObject#Downloads""",
        file=stderr)
    exit(2)

def usage():
    print(USAGE_STRING, file=stderr)
    exit(1)

# there's probably a better way to get the date, but this one works, so ...
try:
    scheduled_time_string = argv[1]
    scheduled_time = float(subprocess.check_output(["date", "+%s", "--date", scheduled_time_string]))
except IndexError:
    usage()
except subprocess.CalledProcessError:
    print("GNU `date` is good at parsing datestrings, but it couldn't make heads or tails of {}".format(argv[1]),
            file=sys.stderr)
    exit(1)

try:
    message = argv[2]
except IndexError:
    print("No message given, but the reminder will fire off. Hopefully you remember what you were thinking of!",
            file=sys.stderr)
    message = "[no message]"

delta = scheduled_time - time.time()
if delta < 0:
    print("Time {} is in the past.".format(time.strftime("%Y-%m-%d %H:%M:%S %Z", time.localtime(scheduled_time))))
    exit(3)

time.sleep(delta)
Notify.init("reminder")
notification = Notify.Notification.new("reminder", message, "face-monkey")
notification.show()