fileio

File I/O module.

exception wmflib.fileio.FileIOError

Bases: WmflibError

Custom exception class for errors of the BlockInFile class.

__annotations__ = {}

__doc__ = 'Custom exception class for errors of the BlockInFile class.'

__module__ = 'wmflib.fileio'

exception wmflib.fileio.LockError

Bases: FileIOError

Custom exception class raised when unable to exclusively lock a file.

__annotations__ = {}

__doc__ = 'Custom exception class raised when unable to exclusively lock a file.'

__module__ = 'wmflib.fileio'

wmflib.fileio.locked_open(file_path: PathLike, file_mode: str = 'r', *, timeout: int = 10) → Generator[IO, None, None]

Context manager to open a file with an exclusive lock on it and a retry logic.

Examples

from wmflib.fileio import locked_open

with locked_open("existing.file") as f:
    text = f.read()

with locked_open("new.out", "w") as f:
    f.write("Some text")

Parameters:

• file_path (os.PathLike) – the file path to open.

• file_mode (str, optional) – the mode in which the file is opened, see open() for details.

• timeout (int, optional) – the total timeout in seconds to wait to acquire the exclusive lock before giving up. Ten tries will be attempted to acquire the lock within the timeout.

Raises:

wmflib.fileio.LockError – on failure to acquire the exclusive lock on the file.

Yields:

file object – the open file with an exclusive lock on it.