如何使用Python Watchdog在目录中发生任何变化时运行函数？

Question

我试图使用看门狗在dir中发生任何变化时运行同步脚本(除了一个特定文件).我只是复制了自述文件中的代码(粘贴在下面),它完成了它所说的内容; 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()

我现在想要在任何变化时运行一个函数(它将整个文件夹同步到远程机器).所以我只event_handler用我自己的功能代替了.但是这给了我以下错误:

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'

有谁知道我在这里做错了什么？欢迎所有提示!

PS.我还想排除文件夹中的一个文件被观看.任何想法我应该怎么做？

Answer 1

您需要子类化并在发送时执行任何操作:

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,Foobar只要检测到更改,您就会看到输出,忽略您可能需要使用的文件[events.PatternMatchingEventHandler] [1].每种方法都有各种方法

要在修改某些内容时执行某些操作,我们可以覆盖on_modified:

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

使用上面的类运行代码event_handler = Event() 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]:您可以覆盖的http://pythonhosted.org/watchdog/api.html#watchdog.events.PatternMatchingEventHandler EventHandler类,这一切都取决于您想要做什么.该LoggingEventHandler班itslef是的子类watchdog.events.FileSystemEventHandler:

class watchdog.events.FileSystemEventHandler Bases:object

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

dispatch(event)将事件 调度到适当的方法.

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

on_any_event(event) Catch-all事件处理程序.

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

on_created(event) 在创建文件或目录时调用.

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

on_deleted(event) 删除文件或目录时调用.

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

on_modified(event) 在修改文件或目录时调用.

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

on_moved(event) 在移动或重命名文件或目录时调用.

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

Answer 2

python 中有很多方法可以跟踪目录中所做的更改。一种这样的方法是使用该watchdog模块。

• 所需模块
  • 要安装看门狗，请在终端中运行此命令。

pip install watchdog

如果您想在创建或修改文件/目录时进行更改（当前在根目录中 - "."），可以使用以下代码来执行此操作：

import time
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler


class Watcher:
    def __init__(self, path):
        self.observer = Observer()
        self.path = path

    def run(self):
        event_handler = Handler()
        self.observer.schedule(event_handler, self.path, recursive=True)
        self.observer.start()
        try:
            while True:
                time.sleep(1)
        except:
            self.observer.stop()
            print("Error")

        self.observer.join()


class Handler(FileSystemEventHandler):
    @staticmethod
    def on_any_event(event):
        # if event.is_directory:
        #     return None
        print(
            "[{}] noticed: [{}] on: [{}] ".format(
                time.asctime(), event.event_type, event.src_path
            )
        )


if __name__ == "__main__":
    w = Watcher(".")
    w.run()

• event.src_path将是完整的文件路径
• event.event_type将被创建、移动等。

如果您想忽略目录更改，只需删除注释即可。

输出：

[Tue Feb  9 00:16:02 2021] noticed: [created] on: [/Users/mt/Documents/stackoverflow/test.txt] 
[Tue Feb  9 00:16:02 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 
[Tue Feb  9 00:16:19 2021] noticed: [created] on: [/Users/mt/Documents/stackoverflow/download.jpg] 
[Tue Feb  9 00:16:19 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 
[Tue Feb  9 00:16:30 2021] noticed: [created] on: [/Users/mt/Documents/stackoverflow/new_folder] 
[Tue Feb  9 00:16:30 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 
[Tue Feb  9 00:16:46 2021] noticed: [deleted] on: [/Users/mt/Documents/stackoverflow/new_folder] 
[Tue Feb  9 00:16:46 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 
[Tue Feb  9 00:16:52 2021] noticed: [deleted] on: [/Users/mt/Documents/stackoverflow/download.jpg] 
[Tue Feb  9 00:16:52 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 
[Tue Feb  9 00:17:00 2021] noticed: [deleted] on: [/Users/mt/Documents/stackoverflow/test.txt] 
[Tue Feb  9 00:17:00 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow] 

该类Observer监视任何文件系统更改，然后将事件分派给事件处理程序。它监视文件系统并查找任何更改。

这EventHandler是一个当文件系统发生问题时将收到通知的对象。一般来说，编写脚本是为了监视创建或修改的任何类型的新文件，例如 csv、txt、xml、jpg 等。

例如，在下面的代码中，PatternMatchingEventHandler继承自该类FileSystemEventHandler并用于执行此操作。这个类的一些有用的方法是：

• on_any_event: 将对任何事件执行。
• on_created：创建文件或目录时执行。
• on_modified：当文件被修改或目录被重命名时执行。
• on_deleted：删除文件或目录时执行。
• on_moved：移动文件或目录时执行。

以下脚本用于使用 .csv 文件仅观察.csvPatternMAtchingEventHandler文件。如果您想观察不止一种类型的文件，您可以进一步扩展模式列表。

import watchdog.events
import watchdog.observers
import time
import sys


class Handler(watchdog.events.PatternMatchingEventHandler):
    def __init__(self):
        # Set the patterns for PatternMatchingEventHandler
        watchdog.events.PatternMatchingEventHandler.__init__(
            self,
            patterns=["*.csv"],
            ignore_directories=True,
            case_sensitive=False,
        )

    def on_any_event(self, event):
        print(
            "[{}] noticed: [{}] on: [{}] ".format(
                time.asctime(), event.event_type, event.src_path
            )
        )


if __name__ == "__main__":
    path = sys.argv[1] if len(sys.argv) > 1 else "."
    event_handler = Handler()
    observer = watchdog.observers.Observer()
    observer.schedule(event_handler, path=path, recursive=True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()

• 在这里，在 的帮助下，PatternMAtchingEventHandler我们可以仅处理与扩展名为.csv 的文件相关的事件。

输出：

[Tue Feb  9 00:18:51 2021] noticed: [created] on: [/Users/mt/Documents/stackoverflow/test.csv] 
[Tue Feb  9 00:18:59 2021] noticed: [modified] on: [/Users/mt/Documents/stackoverflow/test.csv] 
[Tue Feb  9 00:19:12 2021] noticed: [deleted] on: [/Users/mt/Documents/stackoverflow/test.csv]