ACTIONS = {
  1 : "Created",
  2 : "Deleted",
  3 : "Updated",
  4 : "Renamed from something",
  5 : "Renamed to something"
}
FILE_LIST_DIRECTORY = 0x0001

class myThread (threading.Thread):
    def __init__(self, threadID, fileName, directory, origin):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.fileName = fileName
        self.daemon = True
        self.dir = directory
        self.originalFile = origin
    def run(self):
        startMonitor(self.fileName, self.dir, self.originalFile)

def startMonitor(fileMonitoring,dirPath,originalFile):
    hDir = win32file.CreateFile (
        dirPath,
        FILE_LIST_DIRECTORY,
        win32con.FILE_SHARE_READ | win32con.FILE_SHARE_WRITE,
        None,
        win32con.OPEN_EXISTING,
        win32con.FILE_FLAG_BACKUP_SEMANTICS,
        None
    )
    # Wait for new data and call ProcessNewData for each new chunk that's
    # written
    while 1:
        # Wait for a change to occur
        results = win32file.ReadDirectoryChangesW (
            hDir,
            1024,
            False,
            win32con.FILE_NOTIFY_CHANGE_LAST_WRITE,
            None,
            None
        )
        # For each change, check to see if it's updating the file we're
        # interested in
        for action, file_M in results:
            full_filename = os.path.join (dirPath, file_M)
            #print file, ACTIONS.get (action, "Unknown")
            if len(full_filename) == len(fileMonitoring) and action == 3:
                #copy to main file
                ...

为了用轮询和最小依赖来观察单个文件，下面是一个完整的例子，基于Deestan的回答(上面):

import os
import sys 
import time

class Watcher(object):
    running = True
    refresh_delay_secs = 1

    # Constructor
    def __init__(self, watch_file, call_func_on_change=None, *args, **kwargs):
        self._cached_stamp = 0
        self.filename = watch_file
        self.call_func_on_change = call_func_on_change
        self.args = args
        self.kwargs = kwargs

    # Look for changes
    def look(self):
        stamp = os.stat(self.filename).st_mtime
        if stamp != self._cached_stamp:
            self._cached_stamp = stamp
            # File has changed, so do something...
            print('File changed')
            if self.call_func_on_change is not None:
                self.call_func_on_change(*self.args, **self.kwargs)

    # Keep watching in a loop        
    def watch(self):
        while self.running: 
            try: 
                # Look for changes
                time.sleep(self.refresh_delay_secs) 
                self.look() 
            except KeyboardInterrupt: 
                print('\nDone') 
                break 
            except FileNotFoundError:
                # Action on file not found
                pass
            except: 
                print('Unhandled error: %s' % sys.exc_info()[0])

# Call this function each time a change happens
def custom_action(text):
    print(text)

watch_file = 'my_file.txt'

# watcher = Watcher(watch_file)  # simple
watcher = Watcher(watch_file, custom_action, text='yes, changed')  # also call custom action function
watcher.watch()  # start the watch going

ACTIONS = {
  1 : "Created",
  2 : "Deleted",
  3 : "Updated",
  4 : "Renamed from something",
  5 : "Renamed to something"
}
FILE_LIST_DIRECTORY = 0x0001

class myThread (threading.Thread):
    def __init__(self, threadID, fileName, directory, origin):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.fileName = fileName
        self.daemon = True
        self.dir = directory
        self.originalFile = origin
    def run(self):
        startMonitor(self.fileName, self.dir, self.originalFile)

def startMonitor(fileMonitoring,dirPath,originalFile):
    hDir = win32file.CreateFile (
        dirPath,
        FILE_LIST_DIRECTORY,
        win32con.FILE_SHARE_READ | win32con.FILE_SHARE_WRITE,
        None,
        win32con.OPEN_EXISTING,
        win32con.FILE_FLAG_BACKUP_SEMANTICS,
        None
    )
    # Wait for new data and call ProcessNewData for each new chunk that's
    # written
    while 1:
        # Wait for a change to occur
        results = win32file.ReadDirectoryChangesW (
            hDir,
            1024,
            False,
            win32con.FILE_NOTIFY_CHANGE_LAST_WRITE,
            None,
            None
        )
        # For each change, check to see if it's updating the file we're
        # interested in
        for action, file_M in results:
            full_filename = os.path.join (dirPath, file_M)
            #print file, ACTIONS.get (action, "Unknown")
            if len(full_filename) == len(fileMonitoring) and action == 3:
                #copy to main file
                ...

它不应该在windows上工作(也许与cygwin ?)，但对于unix用户，您应该使用“fcntl”系统调用。下面是Python中的一个例子。如果你需要用C语言写的话，基本上是相同的代码(相同的函数名)

import time
import fcntl
import os
import signal

FNAME = "/HOME/TOTO/FILETOWATCH"

def handler(signum, frame):
    print "File %s modified" % (FNAME,)

signal.signal(signal.SIGIO, handler)
fd = os.open(FNAME,  os.O_RDONLY)
fcntl.fcntl(fd, fcntl.F_SETSIG, 0)
fcntl.fcntl(fd, fcntl.F_NOTIFY,
            fcntl.DN_MODIFY | fcntl.DN_CREATE | fcntl.DN_MULTISHOT)

while True:
    time.sleep(10000)

因为没有人提到它，所以我要把它放在那里:在标准库中有一个名为filecmp的Python模块，它有这个cmp()函数来比较两个文件。

只是要确保你没有使用from filecmp import cmp来掩盖Python 2.x中内置的cmp()函数。这在Python 3中是可以的。X，因为不再有这样的内置cmp()函数了。

不管怎样，它的用法是这样的:

import filecmp
filecmp.cmp(path_to_file_1, path_to_file_2, shallow=True)

参数shallow默认为True。如果参数的值为True，则只比较文件的元数据;但是，如果参数的值为False，则比较文件的内容。

也许这个信息对某人有用。

你试过用看门狗吗?

Python API库和shell实用程序来监视文件系统事件。 目录监视变得很容易 一个跨平台的API。 一个shell工具，用于在目录更改时运行命令。 用一个简单的例子开始快速入门…