futures.py

from concurrent.futures import ThreadPoolExecutor
from time import sleep
 
def return_after_5_secs(message):
  sleep(5)
  return message
 
pool = ThreadPoolExecutor(3)
 
future = pool.submit(return_after_5_secs, 
                     ("Hello world"))

print(future.done())
# False
sleep(5)
print(future.done())
# True
print(future.result())
# Hello World