Watchdog 幾種 Observer 型別

• InotifyObserver
• PollingObserver
• WindowsApiObserver
• FSEventsObserver
• KqueueObserver

InotifyObserver

Linux系統用的， 觀察目錄的排程事件，效率比較高。 預設使用

WindowsApiObserver

Windows系統用的， 觀察目錄的排程事件，效率比較高。 預設使用

PollingObserver

與平臺無關，輪詢目錄以檢測檔案的更改，效率比較低。 如果上兩種方式在Linux 或 windows中有問題，可以使用該方法。

其他：

• 不在做詳細講解

FSEventsObserver

用於 darwin(蘋果2000年開源一款操系統)

KqueueObserver

用於，darwin(蘋果2000年開源一款操系統) 和 bsd(伯克利Unix)

官方原始碼

# 是不是Linux系統
if platform.is_linux():
    try:
        from .inotify import InotifyObserver as Observer
    except UnsupportedLibc:
        from .polling import PollingObserver as Observer
# 判斷是不是darwin系統
 

elif platform.is_darwin():
    # FIXME: catching too broad. Error prone
    try:
        from .fsevents import FSEventsObserver as Observer
    except:
        try:
            from .kqueue import KqueueObserver as Observer
            warnings.warn("Failed to import fsevents. Fall back to kqueue")
 

        except:
            from .polling import PollingObserver as Observer
            warnings.warn("Failed to import fsevents and kqueue. Fall back to polling.")
# 判斷是不是bsd系統
elif platform.is_bsd():
    from .kqueue import KqueueObserver as Observer
# 判斷是不是windows系統
elif platform.is_windows():
    # TODO: find a reliable way of checking Windows version and import
    # polling explicitly for Windows XP
    try:
        from .read_directory_changes import WindowsApiObserver as Observer
    except:
        from .polling import PollingObserver as Observer
        warnings.warn("Failed to import read_directory_changes. Fall back to polling.")

else:
    from .polling import PollingObserver as Observer

注意

在Linux系統中,如果無法監聽到檔案目錄的變化可以手動的把Observer修改為PollingObserver
Linux系統中的，掛載的目錄無法正常監聽可以使用下列方法

程式碼如下：

import sys
import time
import logging
# from watchdog.observers import Observer
from watchdog.observers.polling import PollingObserver
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 = PollingObserver()
    observer.schedule(event_handler, path, recursive=True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()