Pidfile featuring stale detection and file-locking, can also be used as context-manager or decorator
PidFile class featuring:
pidfile locking (fcntl)
chmod (default is 0o644)
PidFile can be used as a context manager:
from pid import PidFile with PidFile(): do_something()
PidFile can also be used a a decorator:
from pid.decorator import pidfile @pidfile() def main(): pass if __name__ == "__main__": main()
In default mode PidFile will try to acquire a file lock before anything else. This means that normally you get a PidFileAlreadyLockedError instead of the PidFileAlreadyRunningError when running a program twice.
If you just want to know if a program is already running its easiest to catch just PidFileError since it will capture all possible PidFile exceptions.
Changes in version 2.0.0 and going forward:
pid is now friendly with daemon context managers such as python-daemon where the PidFile context manager is passed as a parameter. The new corrected behaviour will ensure the process environment is determinde at the time of acquiring/checking the lock. Prior behaviour would determine the process environment when instancing the class which may result in incorrect determination of the PID in the case of a process forking after instancing PidFile.
Cleanup of pidfile on termination is done using atexit module. The default SIGTERM handler doesn’t cleanly exit and therefore the atexit registered functions will not execute. A custom handler which triggers the atexit registered functions for cleanup will override the default SIGTERM handler. If a prior signal handler has been configured, then it will not be overridden.
Release history Release notifications | RSS feed
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.