#!/usr/bin/env python2

from icalendar import Calendar, Event, Alarm

input_file = 'Abfuhrtermine.ics'

output_file = 'Abfalltermine_mit_Erinnerung.ics'

ical_file = open(input_file,'r')

calendar = Calendar.from_ical(ical_file.read())

for component in calendar.walk('VEVENT'):

valarm_found = False

for k,v in component.property_items():

if k == 'BEGIN' and v == 'VALARM':

valarm_found = True

if valarm_found == False:

alarm = Alarm()

alarm.add('ACTION', 'DISPLAY')

alarm.add('DESCRIPTION', component.get('SUMMARY'))

alarm.add('TRIGGER;VALUE=DURATION', '-PT12H')

component.add_component(alarm)

ical_file.close()

ical_file_new = open(output_file,'w+')

ical_file_new.write(calendar.to_ical())

ical_file_new.close()