Python Forum

Hi there.

I'm looking into thread.interrupt_main() as a way to exit a thread and close an app irrespective of other threads running.

But, if I've started my app off with:
threads=[threading.Thread(target=func) for func in [ThreadOne, ThreadTwo$
[th.start() for th in threads]
[th.join() for th in threads]

Where does the keyboard handling code go? I don't have a loop anywhere in the main thread anymore?

Many thanks.

Did the last thread not help?

https://python-forum.io/Thread-starting-...8#pid60378

Use threading.Event()
Share this object across all threads you want to close. Instead of using while True, use while not event.is_set():

In the manager thread you set the event: event.set()
Then all threads which are still executing, leaves the loop.

Other possible way are signals. I never used them for threads...

(Oct-16-2018, 09:14 PM)MuntyScruntfundle Wrote: [ -> ]

  [th.start() for th in threads]
  [th.join() for th in threads]

Please, don't replace for loops with parasitic list comprehensions with side effects.

This code just starts threads

for th in threads:
    th.start()

This code starts threads - and builds a list of None values which is immediately discarded.

  [th.start() for th in threads]

While many adopted this style believing it to be Pythonic - it is essentially un-Pythonic, since you implicitly produces parasitic side effect.

Let me demonstrate on a simple function that does nothing

Output:
In [7]: def demo():
   ...:     pass
   ...: 
   ...: 

In [8]: %%timeit
   ...: for _ in range(10000):
   ...:     demo()
   ...: 
698 µs ± 5.5 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

In [9]: %timeit [demo() for _ in range(10000)]
838 µs ± 12.6 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

As you can clearly see, using comprehension instead of a loop (less sexy , I know) costs you about 12% overhead . Where did the resource go? It was wasted managing the redundant temporary list .

Do you comprehend ?