code: def run_and_exit(command_class):
      '''A shortcut for reading from sys.argv and exiting the interpreter'''
      cmd = command_class(sys.argv[1:])
      if cmd.error:
          print('error: {0}'.format(cmd.error))
          sys.exit(1)
      else:
          sys.exit(cmd.run()f run_and_exit(command_class):
      '''A shortcut for reading from sys.argv and exiting the interpreter'''
      cmd = command_class(sys.argv[1:])
      if cmd.error:
          print('error: {0}'.format(cmd.error))
          sys.exit(1)
      else:
          sys.exit(cmd.run())
docs: A shortcut for reading from sys.argv and exiting the interpreter