Refs #23919 -- Replaced six.reraise by raise

django/db/migrations/graph.py

@@ -1,10 +1,8 @@
-import sys
 import warnings
 from collections import deque
 from functools import total_ordering
 
 from django.db.migrations.state import ProjectState
-from django.utils import six
 from django.utils.datastructures import OrderedSet
 
 from .exceptions import CircularDependencyError, NodeNotFoundError
@@ -178,16 +176,12 @@ class MigrationGraph:
         replaced = set(replaced)
         try:
             replacement_node = self.node_map[replacement]
-        except KeyError as exc:
-            exc_value = NodeNotFoundError(
+        except KeyError as err:
+            raise NodeNotFoundError(
                 "Unable to find replacement node %r. It was either never added"
                 " to the migration graph, or has been removed." % (replacement, ),
                 replacement
-            )
-            exc_value.__cause__ = exc
-            if not hasattr(exc, '__traceback__'):
-                exc.__traceback__ = sys.exc_info()[2]
-            six.reraise(NodeNotFoundError, exc_value, sys.exc_info()[2])
+            ) from err
         for replaced_key in replaced:
             self.nodes.pop(replaced_key, None)
             replaced_node = self.node_map.pop(replaced_key, None)
@@ -218,16 +212,12 @@ class MigrationGraph:
         self.nodes.pop(replacement, None)
         try:
             replacement_node = self.node_map.pop(replacement)
-        except KeyError as exc:
-            exc_value = NodeNotFoundError(
+        except KeyError as err:
+            raise NodeNotFoundError(
                 "Unable to remove replacement node %r. It was either never added"
                 " to the migration graph, or has been removed already." % (replacement, ),
                 replacement
-            )
-            exc_value.__cause__ = exc
-            if not hasattr(exc, '__traceback__'):
-                exc.__traceback__ = sys.exc_info()[2]
-            six.reraise(NodeNotFoundError, exc_value, sys.exc_info()[2])
+            ) from err
         replaced_nodes = set()
         replaced_nodes_parents = set()
         for key in replaced:

django/db/migrations/loader.py

@@ -6,7 +6,6 @@ from django.apps import apps
 from django.conf import settings
 from django.db.migrations.graph import MigrationGraph
 from django.db.migrations.recorder import MigrationRecorder
-from django.utils import six
 
 from .exceptions import (
     AmbiguityError, BadMigrationError, InconsistentMigrationHistory,
@@ -256,7 +255,7 @@ class MigrationLoader:
                 is_replaced = any(candidate in self.graph.nodes for candidate in candidates)
                 if not is_replaced:
                     tries = ', '.join('%s.%s' % c for c in candidates)
-                    exc_value = NodeNotFoundError(
+                    raise NodeNotFoundError(
                         "Migration {0} depends on nonexistent node ('{1}', '{2}'). "
                         "Django tried to replace migration {1}.{2} with any of [{3}] "
                         "but wasn't able to because some of the replaced migrations "
@@ -264,11 +263,7 @@ class MigrationLoader:
                             exc.origin, exc.node[0], exc.node[1], tries
                         ),
                         exc.node
-                    )
-                    exc_value.__cause__ = exc
-                    if not hasattr(exc, '__traceback__'):
-                        exc.__traceback__ = sys.exc_info()[2]
-                    six.reraise(NodeNotFoundError, exc_value, sys.exc_info()[2])
+                    ) from exc
             raise exc
 
     def check_consistent_history(self, connection):