Alerts for NS issues by keyword.

ns.py

#!/usr/bin/env python3
# Koen Bollen, 2015

import sys
import urllib.request
import xml.etree.ElementTree

# Train stations you are interested in:
keywords = ("utrecht", "bijlmer", "amstel")
# If one of those keywords is found in the
# rss feed the status will be set to yellow
# and when two or more are found the status
# will be set to red.

# Leave like this (unless changed at NS):
rss = "http://www.ns.nl/storingen/index.rss"



def fetch_xml(url):
  try:
    h = urllib.request.urlopen(url)
    return xml.etree.ElementTree.fromstring(h.read())
  finally:
    h.close()
root = fetch_xml(rss)

found = set()
topics = set()

fields = ('title', 'description')
for item in root.iter('item'):
  texts = map(lambda f: item.find(f).text.strip(), fields)
  text = ' '.join(texts).lower()
  for key in keywords:
    if key in text:
      found.add( key )
      topics.add( item.find('title').text.strip() )

status = 'green'
no_found = len(found)
if no_found == 1:
  status = 'yellow'
elif no_found > 1:
  status = 'red'

if '-v' in sys.argv:
  print(status +':', ', '.join(topics))
  
# send your alert here (ex. using http://pushover.net)

This is my addition to send a notification using pushover:

if '-n' in sys.argv:
  sys.exit(0)

if status != 'green':
  usr_key = "..snip..snip.."
  app_key = "..snip..snip.."
  msg_url = "https://api.pushover.net/1/messages.json"

  data = urllib.parse.urlencode({
    'token': app_key,
    'user': usr_key,
    'priority': 1,
    'url': 'http://www.ns.nl/storingen/',
    'url_title': "NS.nl",
    'title': "NS status: {}".format(status),
    'message': "status {} at: {}".format(status, ', '.join(topics))
  }).encode('utf-8')
  req = urllib.request.Request(msg_url)
  req.add_header("Content-Type","application/x-www-form-urlencoded;charset=utf-8")
  f = urllib.request.urlopen(req, data)
  f.close()