问题：

How do I watch a file for changes using Python?建议使用看门狗,但我发现它只能观看目录,而不是文件.

watchdog-test.py是看门狗的示例脚本：

$python watchdog-test.py ab_test_res.sh &

[1] 30628

fbt@fbt64:~/laike9m$Traceback (most recent call last):

File "watchdog-test.py", line 15, in

observer.start()

File "/usr/local/lib/python2.7/dist-packages/watchdog/observers/api.py", line 255, in start

emitter.start()

File "/usr/local/lib/python2.7/dist-packages/watchdog/utils/__init__.py", line 111, in start

self.on_thread_start()

File "/usr/local/lib/python2.7/dist-packages/watchdog/observers/inotify.py", line 121, in on_thread_start

self._inotify = InotifyBuffer(path, self.watch.is_recursive)

File "/usr/local/lib/python2.7/dist-packages/watchdog/observers/inotify_buffer.py", line 35, in __init__

self._inotify = Inotify(path, recursive)

File "/usr/local/lib/python2.7/dist-packages/watchdog/observers/inotify_c.py", line 187, in __init__

self._add_dir_watch(path, recursive, event_mask)

File "/usr/local/lib/python2.7/dist-packages/watchdog/observers/inotify_c.py", line 363, in _add_dir_watch

raise OSError('Path is not a directory')

OSError: Path is not a directory

那么什么是最好的解决方案？我正在使用Linux(Ubuntu 12.04).顺便说一下,我不想使用民意调查.