Support MultiKernelManager (#51)

nbclient/client.py

@@ -363,25 +363,41 @@ async def async_start_new_kernel_client(self, **kwargs):
  -------
  kc : KernelClient
  Kernel client as created by the kernel manager `km`.
+ kernel_id : string-ized version 4 uuid
+ The id of the started kernel.
  """
  resource_path = self.resources.get('metadata', {}).get('path') or None
  if resource_path and 'cwd' not in kwargs:
  kwargs["cwd"] = resource_path
 
- if self.km.ipykernel and self.ipython_hist_file:
+ # if self.km is a MultiKernelManager, it doesn't have an ipykernel attribute
+ # so no extra_arguments can be passed
+ if hasattr(self.km, 'ipykernel') and self.km.ipykernel and self.ipython_hist_file:
  self.extra_arguments += ['--HistoryManager.hist_file={}'.format(self.ipython_hist_file)]
 
- await ensure_async(self.km.start_kernel(extra_arguments=self.extra_arguments, **kwargs))
+ kernel_id = await ensure_async(self.km.start_kernel(extra_arguments=self.extra_arguments,
+ **kwargs))
 
- self.kc = self.km.client()
+ # if self.km is not a KernelManager, it's probably a MultiKernelManager
+ try:
+ self.km.client
+ km = self.km
+ except AttributeError:
+ try:
+ km = self.km.get_kernel(kernel_id)
+ except AttributeError:
+ raise AttributeError('self.km={} has no client() or get_kernel() method, '
+ 'what is this?'.format(self.km))
+
+ self.kc = km.client()
  await ensure_async(self.kc.start_channels())
  try:
  await ensure_async(self.kc.wait_for_ready(timeout=self.startup_timeout))
  except RuntimeError:
  await self._async_cleanup_kernel()
  raise
  self.kc.allow_stdin = False
- return self.kc
+ return self.kc, kernel_id
 
  start_new_kernel_client = run_sync(async_start_new_kernel_client)
 

nbclient/tests/test_client.py

@@ -20,6 +20,7 @@
 import IPython
 from traitlets import TraitError
 from nbformat import NotebookNode
+from jupyter_client import KernelManager, MultiKernelManager
 from jupyter_client.kernelspec import KernelSpecManager
 from nbconvert.filters import strip_ansi
 from testpath import modified_env
@@ -400,6 +401,43 @@ def test_synchronous_setup_kernel():
  assert executor.kc is None
 
 
+def test_startnewkernel_with_kernelmanager():
+ nb = nbformat.v4.new_notebook()
+ km = KernelManager()
+ executor = NotebookClient(nb, km=km)
+ kc, kernel_id = executor.start_new_kernel_client()
+ # no kernel_id for a single kernel manager
+ assert kernel_id is None
+ # prove it initalized client
+ assert kc is not None
+ # since we are not using the setup_kernel context manager,
+ # cleanup has to be done manually
+ kc.shutdown()
+ km.cleanup()
+ kc.stop_channels()
+
+
+def test_startnewkernel_with_multikernelmanager():
+ nb = nbformat.v4.new_notebook()
+ km = MultiKernelManager()
+ executor = NotebookClient(nb, km=km)
+ kc, kernel_id = executor.start_new_kernel_client()
+ # a multi kernel manager always gives back an id to the started kernel
+ assert kernel_id is not None
+ # prove it initalized client
+ assert kc is not None
+ # since we are not using the setup_kernel context manager,
+ # cleanup has to be done manually
+ kc.shutdown()
+ km.cleanup(kernel_id)
+ km.remove_kernel(kernel_id)
+ # check that the kernel doesn't exist anymore
+ with pytest.raises(KeyError) as e_info:
+ km.get_kernel(kernel_id)
+ assert str(e_info.value) == "'Kernel with id not found: {}'".format(kernel_id)
+ kc.stop_channels()
+
+
 class TestExecute(NBClientTestsBase):
  """Contains test functions for execute.py"""
 

requirements-dev.txt

@@ -1,6 +1,7 @@
 codecov
 coverage
 ipython
+ipykernel
 ipywidgets
 pytest>=4.1
 pytest-cov>=2.6.1