CODEWITHSUNDEEP
pythonpython-2.7contextmanager
Denny Crane
Denny Crane

Reputation: 659

contextmanager fails with logging

I tried to write a lock functionto have only one instance of my script running at the same time. But contextmanager doesn't like it when I add debug messages or other functions into my code.

Any ideas how to workaround this with the same functionality and log messages?

Lock function:

@contextmanager
def lockfile(lock_file='/run/lock/my_script.lock'):
    if os.path.exists(lock_file):
        logging.INFO('Found lock file with pid')
        lf = open(lock_file)
        pid = lf.readline()

        try:
            os.kill(pid, 0)
        except OSError:
            logging.INFO('Removing stale lock file')
            os.remove(lock_file)
        else:
            logging.INFO('Process still running. Aborting')
            sys.exit(1)

    if not os.path.exists(lock_file):
        pid = os.getpid()
        open(lock_file, 'w').write(pid)
        try:
            yield
        finally:
            os.remove(lock_file)

call function

with lockfile():
    do something

Traceback:

Traceback (most recent call last):
  File "/home/vagrant/.pycharm_helpers/pydev/pydevd.py", line 1733, in <module>
    debugger.run(setup['file'], None, None)
  File "/home/vagrant/.pycharm_helpers/pydev/pydevd.py", line 1226, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "/vagrant/my_script", line 274, in <module>
    with lockfile():
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/vagrant/my_script", line 56, in lockfile
    logging.INFO('Found lock file with pid')
TypeError: 'int' object is not callable

Upvotes: 0

Views: 365

Answers (1)

falsetru
falsetru

Reputation: 369054

logging.INFO is not a function. It's an int object that represent logging level which is not callable.

You may want to use logging.info instead.

...
logging.info('Removing stale lock file')

...
logging.info('Process still running. Aborting')

Upvotes: 1

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