__test__ = False def do_import(): import encodings.idna if __name__ == '__main__': import sys import eventlet eventlet.monkey_patch() threading = eventlet.patcher.original('threading') sys.modules.pop('encodings.idna', None) # call "import encodings.idna" in a new thread thread = threading.Thread(target=do_import) thread.start() # call "import encodings.idna" in the main thread do_import() thread.join() print('pass')