@task(name="synchronize_library")
def synchronize_library(user_id):
    from api.models import User

    logger.info("Enter in function")
    user = User.objects.get(pk=user_id)

    attr = getattr(user, "has_soundcloud_account")
    logger.info(callable(attr))

    if user.has_soundcloud_account():
        logger.info("User has account")
        # Do some stuff
    else:
        logger.info("User has not account")
        # Do some stuff

synchronize_library(1)

synchronize_library.delay(1)

[2016-10-25 10:02:44,078: INFO/MainProcess] Received task: synchronize_library[3e8e8a67-c896-4d3e-96fe-0959abed749d]
[2016-10-25 10:02:44,081: INFO/Worker-1] synchronize_library[3e8e8a67-c896-4d3e-96fe-0959abed749d]: Enter in function
[2016-10-25 10:02:44,744: INFO/Worker-1] synchronize_library[3e8e8a67-c896-4d3e-96fe-0959abed749d]: True