notify.py

#!/usr/bin/python
import sys
import gi
gi.require_version('Gio', '2.0')
from gi.repository import Gio
Application = Gio.Application.new("hello.world", Gio.ApplicationFlags.FLAGS_NONE)
Application.register()
Notification = Gio.Notification.new(sys.argv[1])
Notification.set_body(sys.stdin.read())
Icon = Gio.ThemedIcon.new("dialog-information")
Notification.set_icon(Icon)
Application.send_notification(None, Notification)