It provides a way to register a Kernel Comm implementation, as per the Jupyter kernel protocol. It also provides a base Comm implementation and a default CommManager that can be used.
We provide default implementations for usage in IPython:
import comm class MyCustomComm(comm.base_comm.BaseComm): def publish_msg(self, msg_type, data=None, metadata=None, buffers=None, **keys): # TODO implement the logic for sending comm messages through the iopub channel pass comm.create_comm = MyCustomComm
This is typically what ipykernel and JupyterLite's pyolite kernel will do.
import comm comm.create_comm = custom_create_comm comm.get_comm_manager = custom_comm_manager_getter
This is typically what xeus-python does (it has its own manager implementation using xeus's C++ messaging logic).
Libraries like ipywidgets can then use the comms implementation that has been registered by the kernel:
from comm import create_comm, get_comm_manager # Create a comm comm_manager = get_comm_manager() comm = create_comm() comm_manager.register_comm(comm)