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| -rw-r--r-- | Doc/howto/logging-cookbook.rst | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/Doc/howto/logging-cookbook.rst b/Doc/howto/logging-cookbook.rst index b979aa7..44718d5 100644 --- a/Doc/howto/logging-cookbook.rst +++ b/Doc/howto/logging-cookbook.rst @@ -94,6 +94,61 @@ The output looks like this:: 2005-03-23 23:47:11,673 - spam_application - INFO - done with auxiliary_module.some_function() +Logging from multiple threads +----------------------------- + +Logging from multiple threads requires no special effort. The following example +shows logging from the main (initIal) thread and another thread:: + + import logging + import threading + import time + + def worker(arg): + while not arg['stop']: + logging.debug('Hi from myfunc') + time.sleep(0.5) + + def main(): + logging.basicConfig(level=logging.DEBUG, format='%(relativeCreated)6d %(threadName)s %(message)s') + info = {'stop': False} + thread = threading.Thread(target=worker, args=(info,)) + thread.start() + while True: + try: + logging.debug('Hello from main') + time.sleep(0.75) + except KeyboardInterrupt: + info['stop'] = True + break + thread.join() + + if __name__ == '__main__': + main() + +When run, the script should print something like the following:: + + 0 Thread-1 Hi from myfunc + 3 MainThread Hello from main + 505 Thread-1 Hi from myfunc + 755 MainThread Hello from main + 1007 Thread-1 Hi from myfunc + 1507 MainThread Hello from main + 1508 Thread-1 Hi from myfunc + 2010 Thread-1 Hi from myfunc + 2258 MainThread Hello from main + 2512 Thread-1 Hi from myfunc + 3009 MainThread Hello from main + 3013 Thread-1 Hi from myfunc + 3515 Thread-1 Hi from myfunc + 3761 MainThread Hello from main + 4017 Thread-1 Hi from myfunc + 4513 MainThread Hello from main + 4518 Thread-1 Hi from myfunc + +This shows the logging output interspersed as one might expect. This approach +works for more threads than shown here, of course. + Multiple handlers and formatters -------------------------------- |