How do I watch a file for changes?

python file pywin32 watch
Jon Cage picture Jon Cage · Oct 8, 2008 · Viewed 307.9k times · Source

I have a log file being written by another process which I want to watch for changes. Each time a change occurs I'd like to read the new data in to do some processing on it.

What's the best way to do this? I was hoping there'd be some sort of hook from the PyWin32 library. I've found the win32file.FindNextChangeNotification function but have no idea how to ask it to watch a specific file.

If anyone's done anything like this I'd be really grateful to hear how...

[Edit] I should have mentioned that I was after a solution that doesn't require polling.

[Edit] Curses! It seems this doesn't work over a mapped network drive. I'm guessing windows doesn't 'hear' any updates to the file the way it does on a local disk.

Answer

simao picture simao · Jan 14, 2011

Did you try using Watchdog?

Python API library and shell utilities to monitor file system events.

Directory monitoring made easy with

  • A cross-platform API.
  • A shell tool to run commands in response to directory changes.

Get started quickly with a simple example in Quickstart...

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