Locking a file in Python

Question

I need to lock a file for writing in Python. It will be accessed from multiple Python processes at once. I have found some solutions online, but most fail for my purposes as they are often only Unix based or Windows based.

Answer 1

Alright, so I ended up going with the code I wrote here, on my website^{link is dead, view on archive.org} (also available on GitHub). I can use it in the following fashion:

from filelock import FileLock  with FileLock("myfile.txt"):     # work with the file as it is now locked     print("Lock acquired.") 

Answer 2

There is a cross-platform file locking module here: Portalocker

Although as Kevin says, writing to a file from multiple processes at once is something you want to avoid if at all possible.

If you can shoehorn your problem into a database, you could use SQLite. It supports concurrent access and handles its own locking.