[BE][Easy] use pathlib.Path instead of dirname / ".." / pardir (pytorch#129374)

Changes by apply order:

1. Replace all `".."` and `os.pardir` usage with `os.path.dirname(...)`.
2. Replace nested `os.path.dirname(os.path.dirname(...))` call with `str(Path(...).parent.parent)`.
3. Reorder `.absolute()` ~/ `.resolve()`~ and `.parent`: always resolve the path first.

    `.parent{...}.absolute()` -> `.absolute().parent{...}`

4. Replace chained `.parent x N` with `.parents[${N - 1}]`: the code is easier to read (see 5.)

    `.parent.parent.parent.parent` -> `.parents[3]`

5. ~Replace `.parents[${N - 1}]` with `.parents[${N} - 1]`: the code is easier to read and does not introduce any runtime overhead.~

    ~`.parents[3]` -> `.parents[4 - 1]`~

6. ~Replace `.parents[2 - 1]` with `.parent.parent`: because the code is shorter and easier to read.~

Pull Request resolved: pytorch#129374
Approved by: https://github.com/justinchuby, https://github.com/malfet

Author: XuehaiPan

.circleci/codegen_validation/normalize_yaml_fragment.py

@@ -7,7 +7,7 @@
 
 
 # Need to import modules that lie on an upward-relative path
-sys.path.append(os.path.join(sys.path[0], ".."))
+sys.path.append(os.path.dirname(sys.path[0]))
 
 import cimodel.lib.miniyaml as miniyaml
 

.github/scripts/delete_old_branches.py

@@ -22,7 +22,7 @@
 if not TOKEN:
     raise Exception("GITHUB_TOKEN is not set")  # noqa: TRY002
 
-REPO_ROOT = Path(__file__).parent.parent.parent
+REPO_ROOT = Path(__file__).parents[2]
 
 # Query for all PRs instead of just closed/merged because it's faster
 GRAPHQL_ALL_PRS_BY_UPDATED_AT = """

.github/scripts/ensure_actions_will_cancel.py

@@ -6,7 +6,7 @@
 import yaml
 
 
-REPO_ROOT = Path(__file__).resolve().parent.parent.parent
+REPO_ROOT = Path(__file__).resolve().parents[2]
 WORKFLOWS = REPO_ROOT / ".github" / "workflows"
 EXPECTED_GROUP_PREFIX = (
     "${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}"

.github/scripts/generate_binary_build_matrix.py

@@ -94,7 +94,7 @@ def get_nccl_submodule_version() -> str:
     from pathlib import Path
 
     nccl_version_mk = (
-        Path(__file__).absolute().parent.parent.parent
+        Path(__file__).absolute().parents[2]
         / "third_party"
         / "nccl"
         / "nccl"

.github/scripts/gitutils.py

@@ -32,7 +32,7 @@ def get_git_remote_name() -> str:
 def get_git_repo_dir() -> str:
     from pathlib import Path
 
-    return os.getenv("GIT_REPO_DIR", str(Path(__file__).resolve().parent.parent.parent))
+    return os.getenv("GIT_REPO_DIR", str(Path(__file__).resolve().parents[2]))
 
 
 def fuzzy_list_to_dict(items: List[Tuple[str, str]]) -> Dict[str, List[str]]:

.github/scripts/lint_native_functions.py

@@ -26,7 +26,7 @@ def fn(base: str) -> str:
     return str(base / Path("aten/src/ATen/native/native_functions.yaml"))
 
 
-with open(Path(__file__).parent.parent.parent / fn(".")) as f:
+with open(Path(__file__).parents[2] / fn(".")) as f:
     contents = f.read()
 
 yaml = ruamel.yaml.YAML()  # type: ignore[attr-defined]

.github/scripts/test_gitutils.py

@@ -68,7 +68,7 @@ def foo(x: int, y: int) -> int:
 
 class TestGitRepo(TestCase):
     def setUp(self) -> None:
-        repo_dir = BASE_DIR.parent.parent.absolute()
+        repo_dir = BASE_DIR.absolute().parent.parent
         if not (repo_dir / ".git").is_dir():
             raise SkipTest(
                 "Can't find git directory, make sure to run this test on real repo checkout"

benchmarks/dynamo/ci_expected_accuracy/update_expected.py

@@ -71,7 +71,7 @@
     "c1cdfadc-6bb2-4a91-bbf9-3d19e1981cd4/run?format=JSON"
 )
 CSV_LINTER = str(
-    Path(__file__).absolute().parent.parent.parent.parent
+    Path(__file__).absolute().parents[3]
     / "tools/linter/adapters/no_merge_conflict_csv_linter.py"
 )
 

docs/source/scripts/build_opsets.py

@@ -7,9 +7,9 @@
 from torchgen.gen import parse_native_yaml
 
 
-ROOT = Path(__file__).absolute().parent.parent.parent.parent
-NATIVE_FUNCTION_YAML_PATH = ROOT / Path("aten/src/ATen/native/native_functions.yaml")
-TAGS_YAML_PATH = ROOT / Path("aten/src/ATen/native/tags.yaml")
+ROOT = Path(__file__).absolute().parents[3]
+NATIVE_FUNCTION_YAML_PATH = ROOT / "aten/src/ATen/native/native_functions.yaml"
+TAGS_YAML_PATH = ROOT / "aten/src/ATen/native/tags.yaml"
 
 BUILD_DIR = "build/ir"
 ATEN_OPS_CSV_FILE = "aten_ops.csv"

docs/source/scripts/build_quantization_configs.py

@@ -15,7 +15,7 @@
 
 # Create a directory for the images, if it doesn't exist
 QUANTIZATION_BACKEND_CONFIG_IMAGE_PATH = os.path.join(
-    os.path.realpath(os.path.join(__file__, "..")), "quantization_backend_configs"
+    os.path.realpath(os.path.dirname(__file__)), "quantization_backend_configs"
 )
 
 if not os.path.exists(QUANTIZATION_BACKEND_CONFIG_IMAGE_PATH):