style: Fix linter warnings and missing docstring args

Apply linter auto-fixes (unused imports, whitespace, line length) and
add missing batch_size/concurrent/max_workers arg descriptions to
sync_to() docstring.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jdrew82

diffsync/__init__.py

@@ -728,6 +728,9 @@ def sync_to(  # pylint: disable=too-many-arguments, too-many-positional-argument
             sync_attrs: Optional dict of {model_type: set_of_attr_names} to whitelist attributes for syncing.
             exclude_attrs: Optional dict of {model_type: set_of_attr_names} to exclude attributes from syncing.
             sync_filter: Optional callback (action, model_type, ids, attrs) -> bool to approve/reject each operation.
+            batch_size: Optional chunk size for batched sync execution.
+            concurrent: If True, sync independent top-level subtrees in parallel.
+            max_workers: Maximum number of threads for concurrent sync.
 
         Returns:
             Diff between origin object and target

diffsync/helpers.py

@@ -16,7 +16,6 @@
 """
 
 import threading
-from collections import defaultdict
 from collections.abc import Iterable as ABCIterable
 from collections.abc import Mapping as ABCMapping
 from concurrent.futures import ThreadPoolExecutor, as_completed
@@ -519,15 +518,11 @@ def sync_model(  # pylint: disable=too-many-branches, unused-argument
                 dst_model = self._local.model_class.create(adapter=self.dst_diffsync, ids=ids, attrs=attrs)
             elif self._local.action == DiffSyncActions.UPDATE:
                 if dst_model is None:
-                    raise ObjectNotUpdated(
-                        f"Failed to update {self._local.model_class.get_type()} {ids} - not found!"
-                    )
+                    raise ObjectNotUpdated(f"Failed to update {self._local.model_class.get_type()} {ids} - not found!")
                 dst_model = dst_model.update(attrs=attrs)
             elif self._local.action == DiffSyncActions.DELETE:
                 if dst_model is None:
-                    raise ObjectNotDeleted(
-                        f"Failed to delete {self._local.model_class.get_type()} {ids} - not found!"
-                    )
+                    raise ObjectNotDeleted(f"Failed to delete {self._local.model_class.get_type()} {ids} - not found!")
                 dst_model = dst_model.delete()
             else:
                 raise ObjectCrudException(f'Unknown action "{self._local.action}"!')
@@ -536,10 +531,7 @@ def sync_model(  # pylint: disable=too-many-branches, unused-argument
                 status, message = dst_model.get_status()
             else:
                 status = DiffSyncStatus.FAILURE
-                message = (
-                    f"{self._local.model_class.get_type()} "
-                    f"{self._local.action} did not return the model object."
-                )
+                message = f"{self._local.model_class.get_type()} {self._local.action} did not return the model object."
 
         except ObjectCrudException as exception:
             status = DiffSyncStatus.ERROR
@@ -557,9 +549,7 @@ def sync_model(  # pylint: disable=too-many-branches, unused-argument
                 model_type = self._local.model_class.get_type()
                 if model_type not in self.operations:
                     self.operations[model_type] = {"create": [], "update": [], "delete": []}
-                self.operations[model_type][self._local.action].append(
-                    {"ids": ids, "attrs": attrs, "model": dst_model}
-                )
+                self.operations[model_type][self._local.action].append({"ids": ids, "attrs": attrs, "model": dst_model})
 
         return (True, dst_model)
 

tests/unit/test_diff_filtering.py

@@ -15,9 +15,7 @@
 limitations under the License.
 """
 
-import pytest
 
-from diffsync.diff import Diff, DiffElement
 
 
 def test_diff_filter_by_action_create(diff_with_children):

tests/unit/test_diffsync_diff_and_sync_parameters.py

@@ -17,16 +17,14 @@
 
 from typing import Dict, List, Optional
 
-import pytest
-
 from diffsync import Adapter, DiffSyncModel
 from diffsync.enum import DiffSyncFlags
 
-
 # ---------------------------------------------------------------------------
 # Models and adapters used across this test module
 # ---------------------------------------------------------------------------
 
+
 class _Site(DiffSyncModel):
     _modelname = "site"
     _identifiers = ("name",)
@@ -97,6 +95,7 @@ def _make_adapter_pair():
 # model_types scoping
 # ---------------------------------------------------------------------------
 
+
 def test_diff_with_model_types_restricts_to_site_only():
     """Passing model_types={'site'} should exclude child device elements from the diff."""
     src, dst = _make_adapter_pair()
@@ -133,6 +132,7 @@ def test_sync_with_model_types_does_not_touch_excluded_types():
 # sync_attrs / exclude_attrs
 # ---------------------------------------------------------------------------
 
+
 def test_sync_attrs_limits_diff_to_whitelisted_attributes():
     """Only the attributes named in sync_attrs should appear in the diff."""
     src, dst = _make_adapter_pair()
@@ -179,6 +179,7 @@ def test_sync_attrs_and_exclude_attrs_applied_together():
 # filters (query predicates)
 # ---------------------------------------------------------------------------
 
+
 def test_filters_include_matching_objects():
     """Objects whose predicate returns True should be included in the diff."""
     src, dst = _make_adapter_pair()
@@ -190,8 +191,8 @@ def test_filters_include_matching_objects():
             if device_el.type == "device":
                 device_names.add(device_el.name)
 
-    assert "device1" in device_names   # spine in source
-    assert "device3" in device_names   # spine in source
+    assert "device1" in device_names  # spine in source
+    assert "device3" in device_names  # spine in source
     assert "device2" not in device_names  # leaf in source, filtered out
 
 
@@ -222,6 +223,7 @@ def test_filters_do_not_affect_unfiltered_types():
 # sync_filter callback
 # ---------------------------------------------------------------------------
 
+
 def test_sync_filter_blocks_delete_operations():
     """A sync_filter that rejects deletes should preserve objects that only exist in the destination."""
     src, dst = _make_adapter_pair()
@@ -280,6 +282,7 @@ def test_sync_filter_blocks_by_model_type():
 # sync_complete operations summary
 # ---------------------------------------------------------------------------
 
+
 class _TrackingAdapter(_SimpleAdapter):
     """Adapter that captures the operations dict passed to sync_complete."""
 
@@ -354,6 +357,7 @@ def sync_complete(self, source, diff, flags=DiffSyncFlags.NONE, logger=None):
 # concurrent sync
 # ---------------------------------------------------------------------------
 
+
 def test_concurrent_sync_matches_serial_sync():
     """Syncing with concurrent=True should produce the same result as a serial sync."""
     src, dst_serial = _make_adapter_pair()
@@ -377,6 +381,7 @@ def test_sync_defaults_to_serial():
 # Combinations of multiple parameters
 # ---------------------------------------------------------------------------
 
+
 def test_diff_filter_then_sync_with_sync_filter():
     """A pre-filtered Diff combined with a sync_filter should respect both layers."""
     src, dst = _make_adapter_pair()

tests/unit/test_diffsync_model_bulk.py

@@ -17,8 +17,6 @@
 
 from typing import List
 
-import pytest
-
 from diffsync import Adapter, DiffSyncModel