refactor: remove string interpolation in favour of exception chaining

Author: a-ungurianu

kazoo/protocol/connection.py

@@ -806,11 +806,11 @@ def _authenticate_with_sasl(self, host, timeout):
             try:
                 response = sasl_cli.process(challenge=challenge)
             except puresasl.SASLError as err:
-                raise SASLException("library error: %s" % err) from err
-            except puresasl.SASLProtocolException as err:
-                raise AuthFailedError("protocol error: %s" % err) from err
-            except Exception as err:
-                raise AuthFailedError("Unknown error: %s" % err) from err
+                raise SASLException("library error") from err
+            except puresasl.SASLProtocolException as exc:
+                raise AuthFailedError("protocol error") from exc
+            except Exception as exc:
+                raise AuthFailedError("Unknown error") from exc
 
             if sasl_cli.complete and not response:
                 break
@@ -824,9 +824,9 @@ def _authenticate_with_sasl(self, host, timeout):
 
             try:
                 header, buffer, offset = self._read_header(timeout)
-            except ConnectionDropped as ex:
+            except ConnectionDropped as exc:
                 # Zookeeper simply drops connections with failed authentication
-                raise AuthFailedError("Connection dropped in SASL") from ex
+                raise AuthFailedError("Connection dropped in SASL") from exc
 
             if header.xid != xid:
                 raise RuntimeError(

kazoo/recipe/lock.py

@@ -190,12 +190,12 @@ def acquire(self, blocking=True, timeout=None, ephemeral=True):
                 )
             except RetryFailedError:
                 pass
-            except KazooException as ex:
+            except KazooException:
                 # if we did ultimately fail, attempt to clean up
                 if not already_acquired:
                     self._best_effort_cleanup()
                     self.cancelled = False
-                raise ex
+                raise
             if gotten:
                 self.is_acquired = gotten
             if not gotten and not already_acquired: