class Kernel:
name: str
init_code: str = ""
language: str = ""
manager: Optional[KernelManager] = field(default=None, init=False)
client: Optional[KernelClient] = field(default=None, init=False)
report: Dict[str, Any] = field(default_factory=dict, init=False)
def __post_init__(self):
self.report["total"] = datetime.timedelta(0)
kernel_spec = get_kernel_spec(self.name)
self.language = kernel_spec.language
if self.language == "python":
self.init_code = (
"from pheasant.renderers.jupyter.ipython import register_formatters\n"
"register_formatters()")
def shutdown(): # pragma: no cover
if self.manager:
print(f"Shutting down kernel [{self.name}]...", end="")
self.manager.shutdown_kernel()
print("Done.")
atexit.register(shutdown)
def start(self, timeout=10, silent=True) -> KernelClient:
if self.manager:
if self.manager.is_alive():
return self.client
else: # pragma: no cover
raise RuntimeError(f"Kernel {self.name} is not alive.")
def start():
self.manager = KernelManager(kernel_name=self.name)
self.manager.start_kernel()
self.client = self.manager.blocking_client()
self.client.start_channels()
try:
self.client.wait_for_ready(timeout=timeout)
except TimeoutError: # pragma: no cover
self.manager.shutdown_kernel()
return False
else:
self.client.execute_interactive(self.init_code)
return self.client
init = f"Starting kernel [{self.name}]"
progress_bar = progress_bar_factory(total=3, init=init)
now = datetime.datetime.now()
def message(result):
dt = format_timedelta_human(datetime.datetime.now() - now)
return f"Kernel [{self.name}] started ({dt})" if result else "Retrying..."
for k in range(progress_bar.total):
if silent and start():
break
elif silent:
continue
elif progress_bar.progress(start, message):
progress_bar.finish()
break
else:
raise TimeoutError # pragma: no cover
return self.client
def shutdown(self) -> None:
if self.manager:
self.manager.shutdown_kernel()
del self.client
self.client = None
del self.manager
self.manager = None
def restart(self) -> None:
if self.manager:
self.manager.restart_kernel()
if self.client and self.init_code:
self.client.execute_interactive(self.init_code)
def execute(self, code: str, output_hook=None) -> List:
client = self.client or self.start()
outputs = []
def _output_hook(msg):
if output_hook:
output_hook(msg)
output = output_from_msg(msg)
if output:
outputs.append(output)
msg = client.execute_interactive(code, output_hook=_output_hook)
update_report(self.report, msg)
return list(stream_joiner(outputs))
def inspect(self,
code: str,
func: str = "getsource",
output_hook=None) -> List:
self.execute("import inspect")
self.execute(code, output_hook=output_hook)
outputs = self.execute(code_for_inspect(func))
if len(outputs) == 1 and outputs[0]["type"] == "execute_result":
source = ast.literal_eval(outputs[0]["data"]["text/plain"])
return [dict(type="stream", name="source", text=source)]
else:
return outputs
