python - 当 Python Watchdog 的目录发生任何变化时如何运行函数？

Question

我正在尝试使用 watchdog每当目录中发生任何更改时运行同步脚本(一个特定文件除外)。我只是从自述文件(粘贴在下面)中复制了代码，它按照它说的做；记录哪个文件已更改。

import sys
import time
import logging
from watchdog.observers import Observer
from watchdog.events import LoggingEventHandler

if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO,
                        format='%(asctime)s - %(message)s',
                        datefmt='%Y-%m-%d %H:%M:%S')
    path = sys.argv[1] if len(sys.argv) > 1 else '.'
    event_handler = LoggingEventHandler()
    observer = Observer()
    observer.schedule(event_handler, path, recursive=True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()

我现在想在有任何变化时运行一个函数(将整个文件夹同步到远程机器)。所以我只是用我自己的函数替换了 event_handler 。但这给了我以下错误:

Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/Library/Python/2.7/site-packages/watchdog/observers/api.py", line 199, in run
    self.dispatch_events(self.event_queue, self.timeout)
  File "/Library/Python/2.7/site-packages/watchdog/observers/api.py", line 368, in dispatch_events
    handler.dispatch(event)
AttributeError: 'function' object has no attribute 'dispatch'

有人知道我在这里做错了什么吗？欢迎所有提示!

附言。我还想排除文件夹中的一个文件被监视。我应该怎么做？

Answer 1

你需要继承并在 dispatch 中做任何你想做的事:

import sys
import time
import logging
from watchdog.observers import Observer
from watchdog.events import LoggingEventHandler

class Event(LoggingEventHandler):
    def dispatch(self, event):
        print("Foobar")

if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO,
                        format='%(asctime)s - %(message)s',
                        datefmt='%Y-%m-%d %H:%M:%S')
    path = sys.argv[1] if len(sys.argv) > 1 else '.'
    event_handler = Event()
    observer = Observer()
    observer.schedule(event_handler, path, recursive=True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()

如果您运行代码，您将在检测到更改时看到 Foobar 输出，要忽略您可能需要使用 [events.PatternMatchingEventHandler][1] 的文件。每个都有各种方法

要在某事被修改的情况下做某事，我们可以覆盖 on_modified:

class Event(LoggingEventHandler):
    def on_modified(self, event):
        print("Doh")

并使用上面的类和 event_handler = Event() 运行代码并更改文件将输出如下内容:

Doh
Doh
Doh
Doh
Doh
Doh
Doh
2015-10-03 15:33:55 - Created file: ./test.txt___jb_bak___
2015-10-03 15:33:55 - Moved file: from ./test.txt to ./test.txt___jb_old___
2015-10-03 15:33:55 - Moved file: from ./test.txt___jb_bak___ to ./test.txt
2015-10-03 15:33:55 - Deleted file: ./test.txt___jb_old___
Doh

[1]: http://pythonhosted.org/watchdog/api.html#watchdog.events.PatternMatchingEventHandler EventHandler 类你可以覆盖，这完全取决于你想做什么。 LoggingEventHandler 类 itslef 是 watchdog.events.FileSystemEventHandler 的子类:

类 watchdog.events.FileSystemEventHandler 基础:对象

Base file system event handler that you can override methods from.

调度(事件) 将事件分派(dispatch)到适当的方法。

Parameters: event (FileSystemEvent) – The event object representing the file system event.

on_any_event(事件) 捕获所有事件处理程序。

Parameters: event (FileSystemEvent) – The event object representing the file system event.

on_created(事件) 在创建文件或目录时调用。

Parameters: event (DirCreatedEvent or FileCreatedEvent) – Event representing file/directory creation.

on_deleted(事件) 删除文件或目录时调用。

Parameters: event (DirDeletedEvent or FileDeletedEvent) – Event representing file/directory deletion.

on_modified(事件) 修改文件或目录时调用。

Parameters: event (DirModifiedEvent or FileModifiedEvent) – Event representing file/directory modification.

on_moved(事件) 移动或重命名文件或目录时调用。

Parameters: event (DirMovedEvent or FileMovedEvent) – Event representing file/directory movement.