title: Equivalent of thread.interrupt_main() in Python 3
body: <p>In Python 2 there is a function <code>thread.interrupt_main()</code>, which raises a <code>KeyboardInterrupt</code> exception in the main thread when called from a subthread.</p>
  
  <p>This is also available through <code>_thread.interrupt_main()</code> in Python 3, but it's a low-level "support module", mostly for use within other standard modules.</p>
  
  <p>What is the modern way of doing this in Python 3, presumably through the <code>threading</code> module, if there is one?</p>