lesson05_future_cancel.py

# SuperFastPython.com
# example of canceling a task via it's future
from time import sleep
from concurrent.futures import ThreadPoolExecutor

# custom function executed in a worker thread
def work(sleep_time):
 # block for a moment
 sleep(sleep_time)

# protect the entry point
if __name__ == '__main__':
 # create a thread pool
 with ThreadPoolExecutor(1) as exe:
 # start a long running task
 future1 = exe.submit(work, 2)
 running = future1.running()
 print(f'First task running={running}')
 # start a second
 future2 = exe.submit(work, 0.1)
 running = future2.running()
 print(f'Second task running={running}')
 # cancel the second task
 canceled = future2.cancel()
 print(f'Second task was canceled: {canceled}')