[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

src/lightning/fabric/utilities/distributed.py

@@ -322,8 +322,7 @@ def _get_default_process_group_backend_for_device(device: torch.device) -> str:
     device_backend_map = torch.distributed.Backend.default_device_backend_map
     if device.type in device_backend_map:
         return device_backend_map[device.type]
-    else:
-        return "gloo"
+    return "gloo"
 
 
 class _DatasetSamplerWrapper(Dataset):

tests/tests_fabric/utilities/test_distributed.py

@@ -17,9 +17,9 @@
 from lightning.fabric.utilities.distributed import (
     _destroy_dist_connection,
     _gather_all_tensors,
+    _get_default_process_group_backend_for_device,
     _InfiniteBarrier,
     _init_dist_connection,
-    _get_default_process_group_backend_for_device,
     _is_dtensor,
     _set_num_threads_if_needed,
     _suggested_max_num_threads,
@@ -246,13 +246,15 @@ def test_init_dist_connection_registers_destruction_handler(_, atexit_mock):
 def test_get_default_process_group_backend_for_device():
     # register a custom backend for test
     torch.utils.rename_privateuse1_backend("pcu")
+
     def mock_backend(store, group_rank, group_size, timeout):
         pass
+
     torch.distributed.Backend.register_backend(
-    "pccl",
-    lambda store, group_rank, group_size, timeout: mock_backend(store, group_rank, group_size, timeout
-    ),
-    devices=["pcu"])
+        "pccl",
+        lambda store, group_rank, group_size, timeout: mock_backend(store, group_rank, group_size, timeout),
+        devices=["pcu"],
+    )
 
     # test that the default backend is correctly set for each device
     devices = [torch.device("cpu"), torch.device("cuda:0"), torch.device("pcu:0")]