Small changes

ipykernel/iostream.py

@@ -170,10 +170,10 @@ async def _handle_event(self):
                 for _ in range(n_events):
                     event_f = self._events.popleft()
                     event_f()
-        except Exception as e:
+        except Exception:
             if self.thread.__stop.is_set():
                 return
-            raise e
+            raise
 
     def _setup_pipe_in(self):
         """setup listening pipe for IOPub from forked subprocesses"""
@@ -202,10 +202,10 @@ async def _handle_pipe_msgs(self):
         try:
             while True:
                 await self._handle_pipe_msg()
-        except Exception as e:
+        except Exception:
             if self.thread.__stop.is_set():
                 return
-            raise e
+            raise
 
     async def _handle_pipe_msg(self, msg=None):
         """handle a pipe message from a subprocess"""

ipykernel/kernelbase.py

@@ -262,10 +262,10 @@ async def process_control(self):
         try:
             while True:
                 await self.process_control_message()
-        except BaseException as e:
+        except BaseException:
             if self.control_stop.is_set():
                 return
-            raise e
+            raise
 
     async def process_control_message(self, msg=None):
         """dispatch control requests"""
@@ -392,10 +392,10 @@ async def shell_channel_thread_main(self):
                     socket.send_multipart(msg, copy=False)
                 except Exception:
                     self.log.error("Invalid message", exc_info=True)  # noqa: G201
-        except BaseException as e:
+        except BaseException:
             if self.shell_stop.is_set():
                 return
-            raise e
+            raise
 
     async def shell_main(self, subshell_id: str | None):
         """Main loop for a single subshell."""
@@ -426,10 +426,10 @@ async def process_shell(self, socket=None):
         try:
             while True:
                 await self.process_shell_message(socket=socket)
-        except BaseException as e:
+        except BaseException:
             if self.shell_stop.is_set():
                 return
-            raise e
+            raise
 
     async def process_shell_message(self, msg=None, socket=None):
         # If socket is None kernel subshells are not supported so use socket=shell_socket.
@@ -718,8 +718,7 @@ async def execute_request(self, socket, ident, parent):
             cell_meta = parent.get("metadata", {})
             cell_id = cell_meta.get("cellId")
         except Exception:
-            self.log.error("Got bad msg: ")
-            self.log.error("%s", parent)
+            self.log.error("Got bad msg from parent: %s", parent)
             return
 
         stop_on_error = content.get("stop_on_error", True)
@@ -1101,8 +1100,7 @@ async def delete_subshell_request(self, socket, ident, parent):
             content = parent["content"]
             subshell_id = content["subshell_id"]
         except Exception:
-            self.log.error("Got bad msg: ")
-            self.log.error("%s", parent)
+            self.log.error("Got bad msg from parent: %s", parent)
             return
 
         # This should only be called in the control thread if it exists.

ipykernel/subshell_manager.py

@@ -154,7 +154,7 @@ def subshell_id_from_thread_id(self, thread_id) -> str | None:
             for id, subshell in self._cache.items():
                 if subshell.thread.ident == thread_id:
                     return id
-            msg = f"Thread id '{thread_id} does not correspond to a subshell of this kernel"
+            msg = f"Thread id {thread_id!r} does not correspond to a subshell of this kernel"
             raise RuntimeError(msg)
 
     def _create_inproc_pair_socket(
@@ -235,11 +235,11 @@ async def _listen_for_subshell_reply(self, subshell_id: str | None) -> None:
                 msg = await shell_channel_socket.recv_multipart(copy=False)
                 with self._lock_shell_socket:
                     await self._shell_socket.send_multipart(msg)
-        except BaseException as e:
+        except BaseException:
             if not self._is_subshell(subshell_id):
                 # Subshell no longer exists so exit gracefully
                 return
-            raise e
+            raise
 
     async def _process_control_request(self, request, subshell_task) -> dict[str, t.Any]:
         """Process a control request message received on the control inproc
@@ -259,7 +259,7 @@ async def _process_control_request(self, request, subshell_task) -> dict[str, t.
             elif type == "list":
                 reply["subshell_id"] = self.list_subshell()
             else:
-                msg = f"Unrecognised message type {type}"
+                msg = f"Unrecognised message type {type!r}"
                 raise RuntimeError(msg)
         except BaseException as err:
             reply = {

ipykernel/zmqshell.py

@@ -16,9 +16,9 @@
 
 import os
 import sys
+import threading
 import warnings
 from pathlib import Path
-from threading import local
 
 from IPython.core import page, payloadpage
 from IPython.core.autocall import ZMQExitAutocall
@@ -69,7 +69,7 @@ def _flush_streams(self):
     @default("_thread_local")
     def _default_thread_local(self):
         """Initialize our thread local storage"""
-        return local()
+        return threading.local()
 
     @property
     def _hooks(self):
@@ -441,6 +441,9 @@ def autosave(self, arg_s):
 
     @line_magic
     def subshell(self, arg_s):
+        """
+        List all current subshells
+        """
         from ipykernel.kernelapp import IPKernelApp
 
         if not IPKernelApp.initialized():
@@ -454,8 +457,6 @@ def subshell(self, arg_s):
             print("Kernel does not support subshells")
             return
 
-        import threading
-
         thread_id = threading.current_thread().ident
         manager = kernel.shell_channel_thread.manager
         try: