In python, how can a main thread catch the exception from a background thread?

Question

I'm playing around with a simple thread program found in this post: http://pymotw.com/2/Queue/#using-queues-with-threads

The program runs OK, but if modify the worker thread to raise an exception, the main thread doesn't catch it and terminate properly. How do I catch the exception from main thread and terminate the program gracefully?

Answer 1

It is not possible to catch an exception raised on a different thread. You will have to catch the exception on the thread that causes it, and then send a message of some kind to the main thread. You can of course include the actual exception object in the message you send.