filelock

filelock is a platform-independent file locking library for Python that provides inter-process synchronization via OS-level primitives (fcntl on Unix, msvcrt on Windows) with automatic fallback to soft (file-existence) locking. It supports exclusive locks (FileLock, SoftFileLock), SQLite-backed read-write locks (ReadWriteLock, added in 3.21.0), and async variants (AsyncFileLock, AsyncReadWriteLock, added in 3.25.0). The current stable version is 3.25.2, released March 2026; the project ships multiple releases per month and requires Python ≥ 3.10.