comm

import comm import os # This example assumes it's running within a Jupyter kernel environment. # In a real Jupyter setup, the frontend would register a 'my_comm_target'. class MyKernelComm(comm.Comm): def __init__(self, target_name='my_comm_target', data=None, metadata=None, buffers=None): super().__init__(target_name, data, metadata, buffers) print(f"Kernel Comm '{target_name}' opened.") self.on_msg(self._handle_msg) def _handle_msg(self, msg): # msg['content']['data'] contains the message payload from the frontend print(f"Kernel received message: {msg['content']['data']}") if msg['content']['data'].get('action') == 'ping': self.send({'action': 'pong', 'value': msg['content']['data'].get('value')}) print("Kernel sent 'pong'.") def shutdown(self): self.close() print(f"Kernel Comm '{self.target_name}' closed.") # Instantiate the Comm (in a real scenario, this would interact with the frontend) # Note: Running this outside a Jupyter kernel will likely not connect to anything # and 'comm.Comm' might rely on 'get_ipython()' which would not exist. # To simulate, we'll just demonstrate the object creation and basic method calls. # In a live kernel, this object would be managed by the kernel's CommManager. try: # This part would only successfully run inside a live Jupyter kernel # where get_ipython() is available and the kernel manager is active. # For a standalone script, this will raise an error. if os.environ.get('SIMULATE_JUPYTER_KERNEL', 'false').lower() == 'true': my_comm_instance = MyKernelComm(target_name='test_target') my_comm_instance.send({'action': 'init', 'message': 'Hello from kernel!'}) # Simulate receiving a message # In reality, the _handle_msg is called by the kernel's message loop # This manual call is for demonstration purposes in a non-kernel environment my_comm_instance._handle_msg({'content': {'data': {'action': 'ping', 'value': 42}}}) my_comm_instance.shutdown() else: print("To run a more interactive quickstart, execute this code within a Jupyter Notebook or IPython kernel.") print("The 'comm' library provides the low-level API; higher-level libraries like ipywidgets are usually preferred.") except Exception as e: print(f"Could not fully demonstrate 'comm.Comm' outside a live Jupyter kernel. Error: {e}")