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
Read the original article Hit count: 270

Filed under:

python

|

file

|

change

|

pywin32

|

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.

© Stack Overflow or respective owner

Related posts about python

unmet dependencies in Ubuntu 12.04

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried today to install a dvb-card on my Ubuntu 12.04 (Linux blauhai-linux 3.2.0-25-generic #40-Ubuntu SMP Wed May 23 20:30:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux ). The installation failed with an error. After that, i tried to install python (it was already installed but i got this error): linux:~$… >>> More
How can I get sikuli-ide to work?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed sikuli-ide with sudo apt-get install sikuli-ide Everything was fine until I tried to start it from the terminal. I typed sikuli-ide But the only response I got was [info] locale: en_US The application was not started, furthermore there is no desktop file and sikuli-ide does not… >>> More
Getting PATH right for python after MacPorts install

as seen on Super User - Search for 'Super User'
I can't import some python libraries (PIL, psycopg2) that I just installed with MacPorts. I looked through these forums, and tried to adjust my PATH variable in $HOME/.bash_profile in order to fix this but it did not work. I added the location of PIL and psycopg2 to PATH. I know that Terminal is… >>> More
call python with system() in R to run a python script emulating the python console

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to pass a chunk of Python code to Python in R with something like system('python ...'), and I'm wondering if there is an easy way to emulate the python console in this case. For example, suppose the code is "print 'hello world'", how can I get the output like this in R? >>> print… >>> More
Python - Calling a non python program from python?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am currently struggling to call a non python program from a python script. I have a ~1000 files that when passed through this C++ program will generate ~1000 outputs. Each output file must have a distinct name. The command I wish to run is of the form: program_name -input -output -o1 -o2… >>> More

Related posts about file

NTFS Corruption: Files created in Linux corrupted when Windows Boots

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I'm getting some file loss and corruption on my Win7/Ubuntu 12.04 dual boot setup. I have a large shared NTFS partition. I have my Windows Docs/Music/etc. directories on that file and have the comparable directors in Linux setup as a sym. link. I'm using ntfs-3g on the linux side of things to… >>> More
Prevent malicious vulnerability scan increasing load on a server

as seen on Server Fault - Search for 'Server Fault'
Hi all, this week we have been suffering some malicious vulnerability scans to our servers, increasing the load on them, making them nearly unusable. The attack is easy to defend, just blocking the offending ip, but only after discovering it. Is there any form of prevent it? Is it normal that… >>> More
yum update failed

as seen on Server Fault - Search for 'Server Fault'
I have problem doint yum update on my OpenVZ VPS i get this error message : (56/69): glibc-devel-2.5-81.el5_8.7.x86_64.rpm | 2.4 MB 00:00 (57/69): libstdc++-devel-4.1.2-52.el5_8.1.x86_64.rpm | 2.8 MB 00:00 (58/69): binutils-2.17.50.0.6-20.el5_8.3.x86_64.rpm | 2.9 MB … >>> More
Microsoft Management Console stops working when I add snap-in to it

as seen on Super User - Search for 'Super User'
I have Windows 7 Ultimate OS. I'm opening mmc.exe as administrator and trying add Certificates or any other snap-in, then while loading that snap-in MMC breaks and displays following message and after that it closes automatically once I click on close button on that message. What could be the problem… >>> More
Opening a file opens the folder the file is in, not the file itself

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Whenever I try to open a file (such as an .odt, or .doc) from say, the Dash or the Firefox Downloads, Ubuntu 11.10 opens Nautilus to the the folder where the file is, rather than just going to the application and loading the file straight away. In previous releases, when I clicked on a downloaded… >>> More