title: Detect file creation with watchdog
body: <p>I am trying to detect when a file with a given name is created in a directory. I am doing it thanks to <a href="http://pypi.python.org/pypi/watchdog/" rel="noreferrer">watchdog</a>. The creation is correctly detected but I don't know how to terminate the application properly once the detection is done.</p>
  
  <p>My piece of code is the following:</p>
  
  <pre><code>#!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import logging
  import sys
  import time
  
  from watchdog.events import FileSystemEventHandler
  from watchdog.observers import Observer
  
  logging.basicConfig(level=logging.ERROR)
  
  class MyEventHandler(FileSystemEventHandler):
      def __init__(self, observer, filename):
          self.observer = observer
          self.filename = filename
  
      def on_created(self, event):
          print "e=", event
          if not event.is_directory and event.src_path.endswith(self.filename):
              print "file created"
              self.observer.unschedule_all()
              self.observer.stop()
  
  def main(argv=None):
      path = argv[1]
      filename = argv[2]
      observer = Observer()
      event_handler = MyEventHandler(observer, filename)
      observer.schedule(event_handler, path, recursive=False)
      observer.start()
      observer.join()
      return 0
  
  if __name__ == "__main__":
      sys.exit(main(sys.argv))
  </code></pre>
  
  <p>I am new to python and I cannot figure out what is wrong. The detection seems to be scheduled in a dedicated thread and the join() method is waiting for this thread to terminate. Thus, I suppose that I am not calling the right method on the observer to stop waiting/looping, but the watchdog documentation seems really not clear to point out what are the methods that may be used.</p>
  
  <p>Does someone have an idea how I can achieve my goal?</p>