sync.py

from java.io import File
from java.nio.file import Files
from java.nio.file import FileSystems
from java.nio.file.StandardWatchEventKinds import *
from java.nio.file.StandardCopyOption import *
from java.nio.file import Paths

source = '/source/file/path'
target = '/dest/file/path'

sourcef = File(source)

def copy(src, dest):
        counter = 1
        while dest.toFile().exists():
                dest = dest.getParent().resolve(
                                src.getFileName().toString() + ("-%d" % counter));
                counter += 1

        Files.copy(src, dest, [])

def copyFiles():
        for f in sourcef.list():
                src = Paths.get(source, [f])
                dest = Paths.get(target, [f])

                copy(src, dest)

watchService = FileSystems.getDefault().newWatchService()

ckey = Paths.get(source, []).register(watchService, [ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY])

copyFiles()

while 1:
        key = watchService.take()

        for event in key.pollEvents():
                if event.kind() == ENTRY_CREATE:
                        print 'File created = ', event.context(), '; copying it...'
                        src = Paths.get(source, [event.context().toString()])
                        dest =  Paths.get(target, [event.context().toString()])
                        copy(src, dest)
                elif event.kind() == ENTRY_MODIFY:
                        print 'File modified = ', event.context(), '; copying it...'
                        src = Paths.get(source, [event.context().toString()])
                        dest =  Paths.get(target, [event.context().toString()])
                        Files.copy(src, dest, [REPLACE_EXISTING])

        if not key.reset():
                break