Python: two loops at once

Question

This problem has been solved!

I've got a problem: I am new to Python and I want to do multiple loops. I want to run a WebSocket client (Autobahn) and I want to run a loop which shows the filed which are edited in a specific folder (pyinotify or else Watchdog).

Both are running forever, Great. Is there a way to run them at once and send a message via the WebSocket connection while I'm running the FileSystemWatcher, like with callbacks, multithreading, multiprocessing or just separate files?

    factory = WebSocketClientFactory("ws://localhost:8888/ws", debug=False)
    factory.protocol = self.webSocket
    connectWS(factory)
    reactor.run()

If we run this, it will have success. But if we run this:

    factory = WebSocketClientFactory("ws://localhost:8888/ws", debug=False)
    factory.protocol = self.webSocket
    connectWS(factory)
    reactor.run()

    # Websocket client running now,running the filewatcher     

    wm = pyinotify.WatchManager()

    mask = pyinotify.IN_DELETE | pyinotify.IN_CREATE  # watched events

    class EventHandler(pyinotify.ProcessEvent):
        def process_IN_CREATE(self, event):
            print "Creating:", event.pathname

        def process_IN_DELETE(self, event):
            print "Removing:", event.pathname
    handler = EventHandler()
    notifier = pyinotify.Notifier(wm, handler)
    wdd = wm.add_watch('/tmp', mask, rec=True)
    notifier.loop()

This will create 2 loops, but since we already have a loop, the code after 'reactor.run()' will not run at all..

For your information: this project is going to be a sync client.

Thanks a lot!

edit: There is an error. ( http://pastebin.com/zHNG2c6U ) I have no idea what to do now..

webSocket Class:

class webSocket(WebSocketClientProtocol):
    def sendHello(self):
        pass

    def onOpen(self):
        self.sendHello()

    def onMessage(self, msg, binary):
        print "Got echo: " + msg
        reactor.callLater(1, self.sendHello)

    def notify(ignore, filepath, mask):
        print "CALLBACK"
        #print "event %s on %s" % (', '.join(inotify.humanReadableMask(mask)), filepath)

edit2: you are able to see the full code here: http://pastebin.com/iHKRcLVA

Final edit: Everyone, thanks for giving me response! Putting the callback 'def' out of the classes worked well!

Answer 1

Autobahn is built on Twisted, which is an asynchronous app framework. You don't need explicit threading to get this all working. You can instead implement a FileSystemWatcher class using twisted.internet.inotify (there's an example here).

I have no idea how the two components would talk to each other, since I haven't used Twisted for years. But there's an example of bridging to and from a serial port here.

Answer 2

There is a complete demo for notify based watching and publishing over WebSocket in the Autobahn repo here.

This is for Windows, and runs the watching on a background thread. For Unix, you should follow Marcelo's advice and use something asynch which comes with Twisted.