监视目录

方法1：周期性的查看指定目录下的文件及目录，一直保存前一个状态；当查看到当前状态与前一个状态不同时列出不同的内容。

Easy to write and to understand
Uses only standard modules
Works across any platform
Runs in respectable time for small-medium number of files
Doesn't scale well (although it's not too bad if you don't expect many changes)
Doesn't account for updated files (although you could get fancy with os.stat)

import os, timepath_to_watch = "."before = dict ([(f, None) for f in os.listdir (path_to_watch)])while 1:  time.sleep (10)  after = dict ([(f, None) for f in os.listdir (path_to_watch)])  added = [f for f in after if not f in before]  removed = [f for f in before if not f in after]  if added:    print "Added: ", ", ".join (added)  if removed:    print "Removed: ", ", ".join (removed)  before = after
方法2：使用Windows API(FindFirstChangeNotification)进行监控某个目录。

Notifies only when a directory actually changes, so no polling needed
Finer-grained tuning on the change-notification: you could notify on a size change, for example
The code is more complex to understand and manage
You still have to compare the directory listings to find out what's changed

#!/usr/bin/env python
import os
import win32file
import win32event
import win32con
path_to_watch = os.path.abspath (".")
#
# FindFirstChangeNotification sets up a handle for watching
#  file changes. The first parameter is the path to be
#  watched; the second is a boolean indicating whether the
#  directories underneath the one specified are to be watched;
#  the third is a list of flags as to what kind of changes to
#  watch for. We're just looking at file additions / deletions.
#
change_handle = win32file.FindFirstChangeNotification (
  path_to_watch,
  0,
  win32con.FILE_NOTIFY_CHANGE_FILE_NAME
)
#
# Loop forever, listing any file changes. The WaitFor... will
# time out every half a second allowing for keyboard interrupts
# to terminate the loop.
#
try:
  old_path_contents = dict ([(f, None) for f in os.listdir (path_to_watch)])
  while 1:
    result = win32event.WaitForSingleObject (change_handle, 500)
    #
    # If the WaitFor... returned because of a notification (as
    # opposed to timing out or some error) then look for the
    # changes in the directory contents.
    #
    if result == win32con.WAIT_OBJECT_0:
      new_path_contents = dict ([(f, None) for f in os.listdir (path_to_watch)])
      added = [f for f in new_path_contents if not f in old_path_contents]
      deleted = [f for f in old_path_contents if not f in new_path_contents]
      if added: print "Added: ", ", ".join (added)
      if deleted: print "Deleted: ", ", ".join (deleted)
      old_path_contents = new_path_contents
      win32file.FindNextChangeNotification (change_handle)
finally:
  win32file.FindCloseChangeNotification (change_handle)
方法3：使用Windows API(ReadDirectoryChanges)

Notifies only when a directory actually changes, so no polling needed
Finer-grained tuning on the change-notification: you could notify on a size change, for example
You know which files have been altered, and how (at least up to a point: you don't know howa file has been updated or by whom, merely that it has been).
The code is harder to write and understand (especially the initial handle) than the naive approach, but is still easier than the FindFirstChange approach.
Because it's a blocking call, it's difficult to get out of the loop if no change is made to the directory.

#!/usr/bin/env python
import os
import win32file
import win32con
ACTIONS = {
  1 : "Created",
  2 : "Deleted",
  3 : "Updated",
  4 : "Renamed from something",
  5 : "Renamed to something"
}
# Thanks to Claudio Grondi for the correct set of numbers
FILE_LIST_DIRECTORY = 0x0001
path_to_watch = "."
hDir = win32file.CreateFile (
  path_to_watch,
  FILE_LIST_DIRECTORY,
  win32con.FILE_SHARE_READ | win32con.FILE_SHARE_WRITE,
  None,
  win32con.OPEN_EXISTING,
  win32con.FILE_FLAG_BACKUP_SEMANTICS,
  None
)
while 1:
  #
  # ReadDirectoryChangesW takes a previously-created
  # handle to a directory, a buffer size for results,
  # a flag to indicate whether to watch subtrees and
  # a filter of what changes to notify.
  #
  # NB Tim Juchcinski reports that he needed to up
  # the buffer size to be sure of picking up all
  # events when a large number of files were
  # deleted at once.
  #
  results = win32file.ReadDirectoryChangesW (
    hDir,
    1024,
    True,
    win32con.FILE_NOTIFY_CHANGE_FILE_NAME |
     win32con.FILE_NOTIFY_CHANGE_DIR_NAME |
     win32con.FILE_NOTIFY_CHANGE_ATTRIBUTES |
     win32con.FILE_NOTIFY_CHANGE_SIZE |
     win32con.FILE_NOTIFY_CHANGE_LAST_WRITE |
     win32con.FILE_NOTIFY_CHANGE_SECURITY,
    None,
    None
  )
  for action, file in results:
    full_filename = os.path.join (path_to_watch, file)
    print full_filename, ACTIONS.get (action, "Unknown")