1  import multiprocessing, sys
       2  
       3  def foo():
       4      print("123")
       5  
       6  # Because "if __name__ == '__main__'" is missing this will not work
       7  # correctly on Windows.  However, we should get a RuntimeError rather
       8  # than the Windows equivalent of a fork bomb.
       9  
      10  if len(sys.argv) > 1:
      11      multiprocessing.set_start_method(sys.argv[1])
      12  else:
      13      multiprocessing.set_start_method('spawn')
      14  
      15  p = multiprocessing.Process(target=foo)
      16  p.start()
      17  p.join()
      18  sys.exit(p.exitcode)