BTW, I think there's a design mistake in the EnhancedThreadPoolExecutor that's worth avoiding in any std. lib. implementation: the initialiser and uninitialiser for the EnhancedThreadPoolExecutor accept no arguments. In retrospect, it would have been better to have them take the thread itself as a single argument.  We often found ourselves needing this - it's not hard to work around with a threading.current_thread() call, but it's mildly annoying to have to do so.