python - Print statement in Celery scheduled task doesn't appear in terminal -

when run celery -a tasks2.celery worker -b want see "celery task" printed every second. nothing printed. why isn't working?

from app import app celery import celery datetime import timedelta  celery = celery(app.name, broker='amqp://guest:@localhost/', backend='amqp://guest:@localhost/') celery.conf.update(celery_task_result_expires=3600,)  @celery.task def add(x, y):     print "celery task"     return x + y  celerybeat_schedule = {     'add-every-30-seconds': {         'task': 'tasks2.add',         'schedule': timedelta(seconds=1),         'args': (16, 16)     }, } 

this output after staring worker , beat:

[tasks]   . tasks2.add  [info/beat] beat: starting... [info/mainprocess] connected amqp://guest:**@127.0.0.1:5672// [info/mainprocess] mingle: searching neighbors [info/mainprocess] mingle: alone 

you wrote schedule, didn't add celery config. beat saw no scheduled tasks send. example below uses celery.config_from_object(__name__) pick config values current module, can use other config method well.

once configure properly, see messages beat sending scheduled tasks, output tasks worker receives , runs them.

from celery import celery datetime import timedelta  celery = celery(__name__) celery.config_from_object(__name__)  @celery.task def say_hello():     print('hello, world!')  celerybeat_schedule = {     'every-second': {         'task': 'example.say_hello',         'schedule': timedelta(seconds=5),     }, } 

$ celery -a example.celery worker -b -l info  [tasks]   . example.say_hello  [2015-07-15 08:23:54,350: info/beat] beat: starting... [2015-07-15 08:23:54,366: info/mainprocess] connected amqp://guest:**@127.0.0.1:5672// [2015-07-15 08:23:54,377: info/mainprocess] mingle: searching neighbors [2015-07-15 08:23:55,385: info/mainprocess] mingle: alone [2015-07-15 08:23:55,411: warning/mainprocess] celery@netsec-ast-15 ready. [2015-07-15 08:23:59,471: info/beat] scheduler: sending due task every-second (example.say_hello) [2015-07-15 08:23:59,481: info/mainprocess] received task: example.say_hello[2a9d31cb-fe11-47c8-9aa2-51690d47c007] [2015-07-15 08:23:59,483: warning/worker-3] hello, world! [2015-07-15 08:23:59,484: info/mainprocess] task example.say_hello[2a9d31cb-fe11-47c8-9aa2-51690d47c007] succeeded in 0.0012782540870830417s: none