Ctrl-C i.e. KeyboardInterrupt to kill threads in Python

Question

I read somewhere that KeyboardInterrupt exception is only raised in the main thread in Python. I also read that the main thread is blocked while the child thread executes. So, does this mean that CTRL+C can never reach to the child thread. I tried the following code:

def main():
    try:
        thread = threading.Thread(target=f)
        thread.start()  # thread is totally blocking (e.g., while True)
        thread.join()
    except KeyboardInterrupt:
        print "Ctrl+C pressed..."
        sys.exit(1)

def f():
    while True:
        pass  # do the actual work

In this case there is no effect of CTRL+C on the execution. It is like it is not able to listen to the signal. Am I understanding this the wrong way? Is there any other way to kill the thread using CTRL+C?

Answer 1

If you want to have main thread to receive the CTRL+C signal while joining, it can be done by adding timeout to join() call.

The following seems to be working (don't forget to add daemon=True if you want main to actually end):

thread1.start()
while True:
    thread1.join(600)
    if not thread1.isAlive():
        break