Do not use bare except

ipykernel/comm/comm.py

@@ -94,7 +94,7 @@ def open(self, data=None, metadata=None, buffers=None):
                               target_module=self.target_module,
                               )
             self._closed = False
-        except:
+        except Exception:
             comm_manager.unregister_comm(self)
             raise
 

ipykernel/comm/manager.py

@@ -94,7 +94,7 @@ def comm_open(self, stream, ident, msg):
         # Failure.
         try:
             comm.close()
-        except:
+        except Exception:
             self.log.error("""Could not close comm during `comm_open` failure
                 clean-up.  The comm may not have been opened yet.""", exc_info=True)
 

ipykernel/debugger.py

@@ -241,7 +241,7 @@ def _handle_event(self, msg):
         elif msg['event'] == 'continued':
             try:
                 self.stopped_threads.remove(msg['body']['threadId'])
-            except:
+            except Exception:
                 pass
         self.event_callback(msg)
 

ipykernel/eventloops.py

@@ -327,7 +327,7 @@ def handle_int(etype, value, tb):
                 if kernel.shell_stream.flush(limit=1):
                     # events to process, return control to kernel
                     return
-            except:
+            except BaseException:
                 raise
         except KeyboardInterrupt:
             # Ctrl-C shouldn't crash the kernel

ipykernel/kernelapp.py

@@ -630,7 +630,7 @@ def initialize(self, argv=None):
         self.init_io()
         try:
             self.init_signal()
-        except:
+        except Exception:
             # Catch exception when initializing signal fails, eg when running the
             # kernel on a separate thread
             if self.log_level < logging.CRITICAL:

ipykernel/kernelbase.py

@@ -257,7 +257,7 @@ async def process_control(self, msg):
         idents, msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.deserialize(msg, content=True, copy=False)
-        except:
+        except Exception:
             self.log.error("Invalid Control Message", exc_info=True)
             return
 
@@ -309,7 +309,7 @@ async def dispatch_shell(self, msg):
         idents, msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.deserialize(msg, content=True, copy=False)
-        except:
+        except Exception:
             self.log.error("Invalid Message", exc_info=True)
             return
 
@@ -624,7 +624,7 @@ async def execute_request(self, stream, ident, parent):
             store_history = content.get('store_history', not silent)
             user_expressions = content.get('user_expressions', {})
             allow_stdin = content.get('allow_stdin', False)
-        except:
+        except Exception:
             self.log.error("Got bad msg: ")
             self.log.error("%s", parent)
             return
@@ -847,7 +847,7 @@ async def apply_request(self, stream, ident, parent):
             content = parent['content']
             bufs = parent['buffers']
             msg_id = parent['header']['msg_id']
-        except:
+        except Exception:
             self.log.error("Got bad msg: %s", parent, exc_info=True)
             return
 

ipykernel/parentpoller.py

@@ -3,7 +3,7 @@
 
 try:
     import ctypes
-except:
+except ImportError:
     ctypes = None
 import os
 import platform