run_task.py

#!/usr/bin/env python3

from time import sleep
from tasks import add

result = add.delay(4,4)
sleep(0.1) # wait 0.1s
result.ready()
print(result.get())

tasks.py

#!/usr/bin/env python3

from celery import Celery

app = Celery('tasks', backend='redis://localhost', broker='redis://localhost')

@app.task
def add(x, y):
    return x + y