How do I watch a file for changes using Python?

Posted by Jon Cage on Stack Overflow See other posts from Stack Overflow or by Jon Cage
Published on 2008-10-08T11:12:55Z Indexed on 2010/06/13 5:22 UTC
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Filed under:

python

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file

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change

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pywin32

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watch

I have a log file being written by another process which I want to watch for changes. Each time a change occurrs 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.

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