Fix silently fails if path is file gorakhargosh#1034 (Windows only) i…

…ssue by testing if it's a file.

src/watchdog/observers/read_directory_changes.py

@@ -55,7 +55,10 @@ def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT, event_fi
         self._handle = None
 
     def on_thread_start(self):
-        self._handle = get_directory_handle(self.watch.path)
+        watch_path = self.watch.path
+        if os.path.isfile(watch_path):
+            watch_path = os.path.dirname(watch_path)
+        self._handle = get_directory_handle(watch_path)
 
     if platform.python_implementation() == "PyPy":