How to break out of a loop when a certain word is entered?

Question

Python

Let's say there is a while True loop and I need to exit it by entering text or pressing keys. In this case, the loop should run until I perform the above action. How can I implement this? Linux / Ubuntu

Answer 1

If you want a loop that doesn't ask for input each time, you can use a non-blocking read from stdin:

while True:
    try:
        stdin = sys.stdin.read()
        if "\n" in stdin or "\r" in stdin:
            break
    except IOError:
        pass
    time.sleep(1)

Answer 2

If you need a passive loop, in the spirit of "wait for input, enter exit - stop, otherwise we do something and wait again", then the solution above is suitable.
If you want an active loop that does something while the user hasn't entered anything, then input() won't work.
You can build something with threads:
1. the main thread starts the second thread, which executes the body of the loop
2. the main thread goes to input()
3. when input() exits, we send a signal to the second thread to stop and do join() to wait his.