When running the celery worker then each line of the output of the pprint is always prefixed by the timestamp and also is being stripped. This makes it quite unreadable:

[2015-11-05 16:01:12,122: WARNING/Worker-2] {
[2015-11-05 16:01:12,122: WARNING/Worker-2] u'key1'
[2015-11-05 16:01:12,122: WARNING/Worker-2] :
[2015-11-05 16:01:12,122: WARNING/Worker-2] 'value1'
[2015-11-05 16:01:12,122: WARNING/Worker-2] ,
u'_id':
[2015-11-05 16:01:12,122: WARNING/Worker-2] ObjectId('55fff3b74322c53d18ae4687')
...

Is there a way how to tell celery not to format the output of pprint?

UPDATE:

the question was placed a bit wrong. The desired output would look something like this:

[2015-11-05 16:01:12,122: WARNING/Worker-2] 
{u'key1': 'value1',u'_id': ObjectId('55fff3b74322c53d18ae4687'),...

As @xbirkettx mentioned the output format is deffined in the CELERYD_LOG_FORMAT setting, which defaults to [%(asctime)s: %(levelname)s/%(processName)s] %(message)s.

So, in your settings:

CELERYD_LOG_FORMAT = '[%(levelname)s/%(processName)s] %(message)s'

There's also a special setting for a in-task logger, which defaults to:

CELERYD_TASK_LOG_FORMAT = [%(asctime)s: %(levelname)s/%(processName)s]
[%(task_name)s(%(task_id)s)] %(message)s

Remove the asctime key to get rid of the timestamp. Docs on CELERYD_TASK_LOG_FORMAT.

Update

From the docs:

You can also use print(), as anything written to standard out/-errwill be redirected to the logging system (you can disable this, seeCELERY_REDIRECT_STDOUTS).

So, rather than calling pprint.pprint, it is better to format a string with pprint.pformat and then log it.

@periodic_task(run_every=timedelta(seconds=10))
def pprint_dict2():import pprintvalues = {u'key1': 'value1',u'_id1': "ObjectId('55fff3b74322c53d18ae4687')",u'key2': 'value2',u'_id2': "ObjectId('55fff3b74322c53d18ae4687')",u'key3': 'value3',u'_id3': "ObjectId('55fff3b74322c53d18ae4687')",u'key4': 'value4',u'_id3': "ObjectId('55fff3b74322c53d18ae4687')",}s = pprint.pformat(values, width=1)print(s)  # or even better logger.info(...)

Output:

[WARNING/Beat] {u'_id1': "ObjectId('55fff3b74322c53d18ae4687')",u'_id2': "ObjectId('55fff3b74322c53d18ae4687')",u'_id3': "ObjectId('55fff3b74322c53d18ae4687')",u'key1': 'value1',u'key2': 'value2',u'key3': 'value3',u'key4': 'value4'}