NEWOBSERVER.py

#!/usr/bin/python

import objc
from Foundation import NSObject, NSKeyValueObservingOptionNew, NSKeyValueChangeNewKey

"""
Getting help from: 
https://nshipster.com/key-value-observing/
https://svn.red-bean.com/pyobjc/branches/pyobjc-1.4-branch/Examples/00ReadMe.html
https://stackoverflow.com/questions/8317338/how-to-use-kvo-to-detect-when-an-application-gets-active
https://stackoverflow.com/questions/52710089/macos-detect-all-application-launches-including-background-apps

"""

import Foundation
import AppKit
from PyObjCTools import AppHelper
import signal
import os

def takeaction(runningapp):
    if runningapp.bundleIdentifier() == 'com.twitch.desktop':
        os.kill(runningapp.processIdentifier(), signal.SIGKILL)
        print("TWITCH IS NOT ALLOWED!")
    elif runningapp.bundleIdentifier() == 'com.apple.DirectoryUtility':
        print "adrna"
        os.kill(runningapp.processIdentifier(), signal.SIGKILL)
    elif runningapp.bundleIdentifier() == 'com.jamfsoftware.selfservice.mac':
        print 1
        os.kill(runningapp.processIdentifier(), signal.SIGKILL)
class Observer(NSObject):
    def __init__(self):
        #self.currentbid = 0
        pass
    def observeValueForKeyPath_ofObject_change_context_(self, path, object, changeDescription, context):
        if NSKeyValueChangeNewKey == 'new':
            takeaction(object.runningApplications()[-1])
        #print changeDescription[NSKeyValueChangeNewKey]
        
    def willChangeValueForKey_(self, key):
        print "Changed" +key
        

observer = Observer.new()


workspace = Foundation.NSWorkspace.sharedWorkspace() # For runnning apps
#3nc = workspace.notificationCenter()

workspace.addObserver_forKeyPath_options_context_(observer, 'runningApplications', NSKeyValueObservingOptionNew, 0)

AppHelper.runConsoleEventLoop().run()