如何在没有上下文管理器的情况下连接WebSocket？

import websocket

def on_message(ws, message):
    print(message)

def on_error(ws, error):
    print(error)

def on_close(ws):
    print("WebSocket closed")

def on_open(ws):
    # 连接成功后发送消息
    ws.send("Hello, WebSocket!")

if __name__ == "__main__":
    # 创建WebSocket连接
    ws = websocket.WebSocketApp("ws://example.com/ws",
                                on_message=on_message,
                                on_error=on_error,
                                on_close=on_close)
    ws.on_open = on_open

    # 开始监听WebSocket消息
    ws.run_forever()