ModuleNotFoundError: No module named 'celery'

- Tasklist/
  - manage.py
  - Tasklist/
    - __init__.py
    - settings.py
    - celery.py
    - urls.py

from __future__ import absolute_import, unicode_literals

from .celery import app as celery_app

__all__ = ['celery_app']

from __future__ import absolute_import, unicode_literals
import os
from celery import Celery

app = Celery('')

@app.task(bind=True)
def debug_task(self):
    print('Request: {0!r}'.format(self.request))

BROKER_URL = 'redis://localhost:6379/0'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'