new_contents: import sys
  import random
  import argparse
  
  from gostop import GameState, HumanAgent, RandomAgent
  
  
  def main(argv):
      parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
  
      parser.add_argument('-f', '--fixed-random-seed', dest='fixed_random_seed',
                          help='Use a fixed random seed to play a predictable game')
  
      args = parser.parse_args()
  
      if args.fixed_random_seed:
          random.seed(args.fixed_random_seed)
  
      players = [HumanAgent('Human'), RandomAgent('Deep Pink')]
      state = GameState.new_game()
  
      while True:
          current_player = players[state.current_player]
          print('*** {0}'.format(current_player))
          print(state)
  
          possible_actions = state.get_possible_actions()
          if len(possible_actions) == 0:
              raise Exception('No more actions')
          action = current_player.get_action(state, possible_actions)
          print('*** {0} takes action {1}'.format(current_player, str(action)))
  
          last_player = state.current_player
          state = state.generate_successor(action)
          if (state.get_result(last_player) == 1):
              print('*** {0} wins!'.format(players[last_player]))
              break
  
  
  if __name__ == '__main__':
      main(sys.argv[1:])
  
subject: Add basic state machine and game mechanics.