Kunda

Install

pip install kunda

Select an interpreter

from kunda import python_for, find_pythons, venv_env

python_for('~/code/myrepo/src', stop='~/code/myrepo')
find_pythons(roots=['~/code'], current=...)
venv_env(python)

python_for searches parent folders up to stop. It then uses the supplied default or a virtual environment under roots. None means the current interpreter.

venv_env removes frozen-host interpreter variables before starting the child.

Run one kernel

from kunda import Kernel

k = Kernel(cwd='~/code/myrepo', python=..., kernel='ipymini')
await k.start()
out = await k.execute('df.head()', on_output=print)
out.ok, out.text, out.execution_count
await k.complete('df.he', 5)
await k.restart()
await k.shutdown()

ExecOutcome contains execution errors and leaves the kernel available. missing_kernel_module reports a missing launcher after startup fails. Local kernels use jupyter_client; gateway kernels use the same interface over WebSocket.

Keep several kernels alive

from kunda import KernelPool, RuntimeBroker

pool = KernelPool(broker=RuntimeBroker(max_kernels=12), idle=30*60)
k = await pool.get('notebook-1', cwd=..., python=..., inspect=True)
pool.peek('notebook-1')
await pool.close('notebook-1')
await pool.close_all()

Each key has at most one kernel. The pool discards failed starts and keeps busy kernels. idle=0 disables reaping.

RuntimeBroker enforces a process-wide limit. A host can also provide runners and known kernelspecs for other languages.

KernelPool(runner_for=lambda lang: MyRustRunner if lang == 'rust' else None,
           known_kernels={'julia': 'julia-1.10'})

Install kernel support

from kunda import kernel_support, install_kernel_support, installable

kernel_support(python)
installable(python)
install_kernel_support(python)

Installation uses the host’s installed package versions. It fails when either launcher still cannot import.

Inspect live variables

With inspect=True, Kunda starts Dhrishti inside the kernel and reads its registry. A matching Python minor version uses the host package. Other versions use the project installation.