Jan-Philip Gehrcke added the comment: For Python 3.5, I have attached a patch that - adds relevant test cases to test_threading.py which probe the interpreter's stderr output for compliance with what the docs state. - makes sys.exit(msg) write msg to stderr, even if called from a non-primary thread, so that the tests succeed. If we take this path, the documentation for 3.5 does not need to be adjusted. The discussion in this thread diversified itself a bit:

Why don't threads have their own ThreadExit exception, rather than overloading the use, and therefore, the meaning, of the SystemExit exception? sys.exit and the SystemExit exception should *only* be used to exit the entire system, not just a thread!

While I absolutely agree that this would be conceptually cleaner, implementing this would be a larger refactoring task. Deciding whether this should be done or not slows this issue down, and I think this discussion should probably be taken elsewhere. ---------- versions: +Python 3.5 -Python 3.1, Python 3.2 Added file: http://bugs.python.org/file37986/issue6634_py35.patch _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue6634> _______________________________________