From ArchWiki

Newschecker.py

This is a little script that I wrote to check the rss feeds of various websites for updates, ect. It uses python's urllib, and can be somewhat slow for somewebsites. The output is plain text; the script below displays the dates that websites were last updated.

To use it, do the following:

1. Edit the pre variable, adding your username. By default, the script will create a configureation file in ~/.newsrc. This can be changed to anywhere where you would like to save this file.
2. Declare any feeds that you would like to check. This is accomplished by adding a dictionary following this template:

Feed_Name = {"name":"Feed's Name", \
             "feed":"URL of the feed's location", \
             "n1":"", \
             "n2":"", \
             "update":0}

Don't edit the last three entries.

1. Add your feed to the sites list
2. This is the tricky part, since rss feeds are not standardized across all websites, you need to add a new function for processing your feed. I won't go into details how to do that here, however, good tutorials can be found here and here. You will also need to add a call for the function inside of the check() function.
3. The print_filler() function can be edited to customize what is displayed if a feed has not been updated.
4. Whenever you add a new feed, you must delete the old newsrc file.

I personally use this program in conjunction with conky, having it executed with a command like this:

${execi 1800 python /path/to/newscheck.py}

This function will find the current version of a sourceforge project:

def process_sourceforge(urlxml):
        reflist = urlxml.getElementsByTagName("item")
        sites[2]["n2"] = reflist[0].childNodes[1].childNodes[0].nodeValue[a:b]

where a is the number of letters in the project's name plus 1 and the difference between a and b is the number of digits in the projects version number (including any periods, hyphens, etc).

This function will return the last time a sourceforge project was updated:

def process_sourceforge(urlxml):
        reflist = urlxml.getElementsByTagName("item")
        sites[2]["n2"] = reflist[0].childNodes[11].childNodes[0].nodeValue

#!/usr/bin/env python

#   Copywrite 2006 Peter Garceau
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
# 
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#  
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 
#   USA.
#

import os
from xml.dom import minidom
import xml.dom.ext
import urllib

#Defines the path to rc file
pre = "/home/username"
rc = os.path.join(pre,".newsrc")
    
#Declair feeds here
swiftfox = {"name":"Swiftfox", \
               "feed":"http://rss.getswiftfox.com/rss.xml", \
               "n1":"", \
               "n2":"", \
               "update":0}

quodlibet = {"name":"Quodlibet", \
               "feed":"http://www.sacredchao.net/quodlibet/timeline?daysback=90&max=50&milestone=on&format=rss", \
               "n1":"", \
               "n2":"", \
               "update":0}

#Add feeds to this list
sites = [swiftfox, quodlibet]

#Creates a new config file
def makerc():
    doc = xml.dom.minidom.Document()
    root_element = doc.createElement("newsrc")
    doc.appendChild(root_element)
    for a in sites:
           site_element = doc.createElement("site")
           root_element.appendChild(site_element)
           site_element.setAttribute("name",a["name"])
           blank = doc.createTextNode("Initialized")
           site_element.appendChild(blank)
           xml.dom.ext.PrettyPrint(doc, open(rc, "w"))
    
#Loads an rc file
def load():
    doc = minidom.parse(rc)
    reflist = doc.getElementsByTagName('site')
    for a in sites:
           for b in reflist:
                   if a["name"] == b.getAttribute("name"):
                           a["n1"] = b.childNodes[0].nodeValue 

#Checks the feed on the internet
def check():
       for a in sites:
               try:
                       urlget = urllib.urlopen(a["feed"])
                       urlxml = minidom.parse(urlget)
                       urlget.close()
                       if a["name"] == "Swiftfox":
                               process_swiftfox(urlxml)
                       if a["name"] == "Quodlibet":
                               process_quodlibet(urlxml)
               except IOError:
                       print "Cannot Connect to Website"

#Processes the swiftfox feed
def process_swiftfox(urlxml):
       reflist = urlxml.getElementsByTagName("item")
       for a in reflist:
               if a.childNodes[9].childNodes[0].nodeValue[:8] == "Swiftfox":
                       sites[0]["n2"] = a.childNodes[7].childNodes[0].nodeValue


#Process the quodlibet feed
def process_quodlibet(urlxml):
       reflist = urlxml.getElementsByTagName("item")
       sites[1]["n2"] = reflist[0].childNodes[3].childNodes[0].nodeValue


#checks if feed has been updated
def check_update():
       for a in sites:
               if a["n1"] == a["n2"]:
                       a["update"] = 0
               else:
                       a["update"] = 1

#prints final output of program
def final_print():
       doc = minidom.parse(rc)
       for a in sites:
               if a["update"] == 1:
                       for b in doc.childNodes[0].childNodes:
                               try:
                                       if b.getAttribute("name") == a["name"]:
                                               b.childNodes[0].nodeValue = a["n2"]
                               except AttributeError:
                                       pass
                       print " " + "NEW" + " " + a["name"] + " updated " + a["n2"] 
       xml.dom.ext.PrettyPrint(doc, open(rc, "w"))

#prints filler at the end of the program, for formatting purposes
def print_filler():
       for a in sites:
               if a["update"] == 0:
                       print " " + a["name"] + " updated " + a["n1"]

try:
       isitthere = open(rc)
       isitthere.close()
except IOError:
       makerc()

load()
check()
check_update()
final_print()
print_filler()