Celery: Is There A Way To Write Custom Json Encoder/decoder?

I have some objects I want to send to celery tasks on my application. Those objects are obviously not json serializable using the default json library. Is there a way to make celer

Solution 1:

A bit late here, but you should be able to define a custom encoder and decoder by registering them in the kombu serializer registry, as in the docs: http://docs.celeryproject.org/en/latest/userguide/calling.html#serializers.

For example, the following is a custom datetime serializer/deserializer (subclassing python's builtin json module) for Django:

myjson.py (put it in the same folder of your settings.py file)

import json
from datetime import datetime
from time import mktime

classMyEncoder(json.JSONEncoder):   
    defdefault(self, obj):
        ifisinstance(obj, datetime):
            return {
                '__type__': '__datetime__', 
                'epoch': int(mktime(obj.timetuple()))
            }
        else:
            return json.JSONEncoder.default(self, obj)

defmy_decoder(obj):
    if'__type__'in obj:
        if obj['__type__'] == '__datetime__':
            return datetime.fromtimestamp(obj['epoch'])
    return obj

# Encoder function      defmy_dumps(obj):
    return json.dumps(obj, cls=MyEncoder)

# Decoder functiondefmy_loads(obj):
    return json.loads(obj, object_hook=my_decoder)

settings.py

# Register your new serializer methods into kombufrom kombu.serialization import register
from .myjson import my_dumps, my_loads

register('myjson', my_dumps, my_loads, 
    content_type='application/x-myjson',
    content_encoding='utf-8') 

# Tell celery to use your new serializer:
CELERY_ACCEPT_CONTENT = ['myjson']
CELERY_TASK_SERIALIZER = 'myjson'
CELERY_RESULT_SERIALIZER = 'myjson'