[BE][Easy] replace import pathlib with from pathlib import Path (#129426)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/129426
Approved by: https://github.com/malfet

test/test_serialization.py

@@ -1,40 +1,58 @@
 # Owner(s): ["module: serialization"]
 
-import torch
-import unittest
-import io
-import tempfile
-import os
-import gc
-import sys
-import zipfile
-import warnings
-import gzip
 import copy
+import gc
+import gzip
+import io
+import os
 import pickle
-import shutil
-import pathlib
 import platform
+import shutil
+import sys
+import tempfile
+import unittest
+import warnings
+import zipfile
 from collections import namedtuple, OrderedDict
 from copy import deepcopy
 from itertools import product
+from pathlib import Path
 
-from torch._utils_internal import get_file_path_2
+import torch
 from torch._utils import _rebuild_tensor
-from torch.utils._import_utils import import_dill
-from torch.serialization import check_module_version_greater_or_equal, get_default_load_endianness, \
-    set_default_load_endianness, LoadEndianness, SourceChangeWarning
-
-from torch.testing._internal.common_utils import (
-    IS_FILESYSTEM_UTF8_ENCODING, TemporaryDirectoryName,
-    TestCase, IS_FBCODE, IS_WINDOWS, TEST_DILL, run_tests, download_file, BytesIOContext, TemporaryFileName,
-    parametrize, instantiate_parametrized_tests, AlwaysWarnTypedStorageRemoval, serialTest, skipIfTorchDynamo)
+from torch._utils_internal import get_file_path_2
+from torch.serialization import (
+    check_module_version_greater_or_equal,
+    get_default_load_endianness,
+    LoadEndianness,
+    set_default_load_endianness,
+    SourceChangeWarning,
+)
 from torch.testing._internal.common_device_type import instantiate_device_type_tests
 from torch.testing._internal.common_dtype import all_types_and_complex_and
+from torch.testing._internal.common_utils import (
+    AlwaysWarnTypedStorageRemoval,
+    BytesIOContext,
+    download_file,
+    instantiate_parametrized_tests,
+    IS_FBCODE,
+    IS_FILESYSTEM_UTF8_ENCODING,
+    IS_WINDOWS,
+    parametrize,
+    run_tests,
+    serialTest,
+    skipIfTorchDynamo,
+    TemporaryDirectoryName,
+    TemporaryFileName,
+    TEST_DILL,
+    TestCase,
+)
 from torch.testing._internal.two_tensor import TwoTensor  # noqa: F401
+from torch.utils._import_utils import import_dill
+
 
 if not IS_WINDOWS:
-    from mmap import MAP_SHARED, MAP_PRIVATE
+    from mmap import MAP_PRIVATE, MAP_SHARED
 else:
     MAP_SHARED, MAP_PRIVATE = None, None
 
@@ -988,7 +1006,7 @@ class TestSerialization(TestCase, SerializationMixin):
         model = torch.nn.Conv2d(20, 3200, kernel_size=3)
 
         with TemporaryFileName() as fname:
-            path = pathlib.Path(fname)
+            path = Path(fname)
             torch.save(model.state_dict(), path)
             torch.load(path, weights_only=weights_only)
 
@@ -4008,7 +4026,7 @@ class TestSerialization(TestCase, SerializationMixin):
         finally:
             set_default_load_endianness(current_load_endian)
 
-    @parametrize('path_type', (str, pathlib.Path))
+    @parametrize('path_type', (str, Path))
     @parametrize('weights_only', (True, False))
     @unittest.skipIf(IS_WINDOWS, "NamedTemporaryFile on windows")
     def test_serialization_mmap_loading(self, weights_only, path_type):