Python 即使删除了目录，被删除事件处理程序上的看门狗也始终将事件标记为文件

我正在用python创建一个看门狗，当我删除一个文件夹时，它会将其记录为文件删除，而不是目录被删除。我已经发布了一个完整的工作从我的代码。我唯一的问题是

event.is_directory

总是返回

false

filesystem.py

import sys 
import time
import logging 
import tkinter as tk
from tkinter import filedialog

from watchdog.observers import Observer 
from watchdog.events import LoggingEventHandler, FileSystemEventHandler

class OnMyWatch:

    def __init__(self, watch_src, watch_dest):
        self.observer = Observer()
        self.watch_src = watch_src
        self.watch_dest = watch_dest


    def run(self):
        event_handler = Handler()
        self.observer.schedule(event_handler, watch_src, recursive = True)
        self.observer.start()
        try:
            while True:
                time.sleep(5)
        except:
            self.observer.stop()
            print("Observer Stopped")

        self.observer.join()


class Handler(FileSystemEventHandler):

    def on_deleted(self, event):
        if event.is_directory:
            print("Watchdog has registered a deleted directory event")
        else:
            print("Watchdog has registered a deleted file event") 


if __name__ == "__main__":
    root = tk.Tk()
    root.withdraw()

    watch_src = filedialog.askdirectory()
    watch_dest = filedialog.askdirectory()

    watch = OnMyWatch(watch_src, watch_dest)
    watch.run()