text: import pywebio, time
  from pywebio.output import *
  from pywebio.session import *
  
  goboard_size = 15
  # -1 -> none, 0 -> black, 1 -> white
  goboard = [
      [-1] * goboard_size
      for _ in range(goboard_size)
  ]
  
  def winner():  # return winner piece, return None if no winner
      for x in range(2, goboard_size - 2):
          for y in range(2, goboard_size - 2):
              # check if (x,y) is the win center
              if goboard[x][y] != -1 and any([
                  all(goboard[x][y] == goboard[m][n] for m, n in [(x - 2, y), (x - 1, y), (x + 1, y), (x + 2, y)]),
                  all(goboard[x][y] == goboard[m][n] for m, n in [(x, y - 2), (x, y - 1), (x, y + 1), (x, y + 2)]),
                  all(goboard[x][y] == goboard[m][n] for m, n in [(x - 2, y - 2), (x - 1, y - 1), (x + 1, y + 1), (x + 2, y + 2)]),
                  all(goboard[x][y] == goboard[m][n] for m, n in [(x - 2, y + 2), (x - 1, y + 1), (x + 1, y - 1), (x + 2, y - 2)]),
              ]):
                  return ['⚫', '⚪'][goboard[x][y]]
  
  session_id = 0          # auto incremented id for each session
  current_turn = 0        # 0 for black, 1 for white
  player_count = [0, 0]   # count of player for two roles
  def main():
      """Online Shared Gomoku Game
  
      A web based Gomoku (AKA GoBang, Five in a Row) game made with PyWebIO under 100 lines of Python code."""
      global session_id, current_turn, goboard
      if winner():  # The current game is over, reset game
          goboard = [[-1] * goboard_size for _ in range(goboard_size)]
          current_turn = 0
  
      my_turn = session_id % 2
      my_chess = ['⚫', '⚪'][my_turn]
      session_id += 1
      player_count[my_turn] += 1
  
      @defer_call
      def player_exit():
          player_count[my_turn] -= 1
  
      set_env(output_animation=False)
      put_html("""<style> table th, table td { padding: 0px !important;} button {padding: .75rem!important; margin:0!important} </style>""")  # Custom styles to make the board more beautiful
  
      put_markdown(f"""# Online Shared Gomoku Game
      All online players are assigned to two groups (black and white) and share this game. \nYou can open this page in multiple tabs of your browser to simulate multiple users.
      This application uses less than 100 lines of code, the source code is [here](https://github.com/wang0618/PyWebIO/blob/dev/demos/gomoku_game.py)
      Currently online player: {player_count[0]} for ⚫, {player_count[1]} for ⚪.
      Your role is {my_chess}.
      """, lstrip=True)
  
      def set_stone(pos):
          global current_turn
          if current_turn != my_turn:
              toast("It's not your turn!!", color='error')
              return
          x, y = pos
          goboard[x][y] = my_turn
          current_turn = (current_turn + 1) % 2
  
      @use_scope('goboard', clear=True)
      def show_goboard():
          table = [
              [
                  put_buttons([dict(label=' ', value=(x, y), color='light')], onclick=set_stone) if cell == -1 else [' ⚫', ' ⚪'][cell]
                  for y, cell in enumerate(row)
              ]
              for x, row in enumerate(goboard)
          ]
          put_table(table)
  
      show_goboard()
      while not winner():
          with use_scope('msg', clear=True):
              current_turn_copy = current_turn
              if current_turn_copy == my_turn:
                  put_text("It's your turn!")
              else:
                  put_row([put_text("Your opponent's turn, waiting... "), put_loading().style('width:1.5em; height:1.5em')], size='auto 1fr')
              while current_turn == current_turn_copy:  # wait for next move
                  time.sleep(0.2)
              show_goboard()
      with use_scope('msg', clear=True):
          put_text('Game over. The winner is %s!\nRefresh page to start a new round.' % winner())
  
  
  if __name__ == '__main__':
      pywebio.start_server(main, debug=True, port=8080, cdn=False)
  