names.rst

xotl.tools.names -- Utilities for handling objects names

xotl.tools.names

nameof(*objects, depth=1, inner=False, typed=False, full=False, safe=False)

identifier_from(obj)

Use cases for getting the name of an object

The function nameof is useful for cases when you get a value and you need a name. This is a common need when doing framework-level code that tries to avoid repetition of concepts.

Solutions with nameof

Properly calculate the tasks' name in Celery applications

Celery warns about how to import the tasks. If in a module you import your task using an absolute import, and in another module you import it using a relative import, Celery regards them as different tasks. You must either use a consistent import style, or give a name for the task. Using nameof you can easily fix this problem.

Assume you create a celapp.tasks.basic module with this code:

celapp.tasks.basic

__name__ = 'celapp.tasks.basic'

celapp.tasks.basic

>>> def celery_task(celeryapp, args,kwargs): ... def decorator(func): ... from xotl.tools.names import nameof ... taskname = nameof(func, full=True, inner=True) ... return celeryapp.task(name=taskname,args, **kwargs)(func) ... return decorator

>>> from celery import Celery >>> app = Celery() >>> @celery_task(app) ... def add(x, y): ... return x + y

Then importing the task directly in a shell will have the correct name:

>>> from celapp.tasks.basic import add
>>> add.name
'celapp.tasks.basic.add'

Another module that imports the task will also see the proper name. Say you have the module celapp.consumer:

celapp.consumer

__name__ = 'celapp.consumer'

celapp.consumer

>>> from .tasks import basic

>>> def get_name(taskname): ... task = getattr(basic, taskname) ... return task.name

Then:

>>> from celapp.consumer import get_name >>> get_name('add') 'celapp.tasks.basic.add'

Despite that you imported the basic module with a relative import the name is fully calculated.