This module is a replacement for python-daemon pidfile module. TimeoutPIDLockFile class from pidfile implements "advisory" locking. Essentially, it does not really lock anything. It simply checks lock file existence and, as a result, it can't detect certain situations like server process crush and release the lock.
This module uses python's fcntl facility to lock the PID file. That means that is if daemon process is terminated unexpectedly, lock is automatically released and daemon can be restarted.
pip install pidlockfile
From the project top level directory execute:
python -m unittest discover -v
python-daemon-example is a minimalistic example that demonstrates how to use python-daemon with pidlockfile