Filter PEP 798 scanner inputs

scripts/find_and_fix_pep798.py

@@ -24,7 +24,9 @@
 The rewritten source uses Python 3.15+ syntax, so fixed files need 3.15+.
 
 Usage:
-    scripts/find_and_fix_pep798.py [--fix] PATH [PATH ...]
+    scripts/find_and_fix_pep798.py [--fix] [PATH ...]
+
+If no path is provided, the current working directory is searched.
 
 Without ``--fix`` the script only reports and exits with status 1 if any
 opportunities were found.
@@ -126,7 +128,7 @@
 
 def _segment(source: str, offsets: _Offsets, node: ast.expr, parens: tuple) -> str:
     start = offsets.offset(node.lineno, node.col_offset)
     end = offsets.offset(node.end_lineno, node.end_col_offset)
     text = source[start:end]
     return f"({text})" if isinstance(node, parens) else text
 
@@ -213,14 +215,26 @@
 def iter_python_files(paths: Iterable[Path]) -> Iterator[Path]:
     for path in paths:
         if path.is_dir():
-            yield from sorted(path.rglob("*.py"))
-        else:
+            yield from sorted(
+                candidate
+                for candidate in path.rglob("*.py")
+                if not any(part.startswith(".") for part in candidate.parent.parts)
+            )
+        elif path.suffix == ".py" and not any(
+            part.startswith(".") for part in path.parent.parts
+        ):
             yield path
 
 
 def main(argv: list[str] | None = None) -> int:
     parser = argparse.ArgumentParser(description=__doc__.split("\n\n")[0])
-    parser.add_argument("paths", nargs="+", type=Path, help="files or directories")
+    parser.add_argument(
+        "paths",
+        nargs="*",
+        type=Path,
+        default=[Path.cwd()],
+        help="Python files or directories (defaults to the current directory)",
+    )
     parser.add_argument("--fix", action="store_true", help="rewrite files in place")
     args = parser.parse_args(argv)
 

tests/test_find_and_fix_pep798.py

@@ -97,13 +97,16 @@ def test_multiline_comprehension() -> None:
 
 def test_iter_python_files(tmp_path: Path) -> None:
     (tmp_path / "sub").mkdir()
+    (tmp_path / ".hidden").mkdir()
     first = tmp_path / "a.py"
     second = tmp_path / "sub" / "b.py"
     other = tmp_path / "c.txt"
-    for path in (first, second, other):
+    hidden = tmp_path / ".hidden" / "hidden.py"
+    for path in (first, second, other, hidden):
         path.write_text("")
     assert list(iter_python_files([tmp_path])) == [first, second]
-    assert list(iter_python_files([other])) == [other]
+    assert list(iter_python_files([other])) == []
+    assert list(iter_python_files([hidden])) == []
 
 
 def test_main_reports_without_fixing(
@@ -137,6 +140,18 @@ def test_main_clean_file_returns_zero(
     assert "0 PEP 798 opportunities found" in capsys.readouterr().out
 
 
+def test_main_defaults_to_current_directory(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+) -> None:
+    path = tmp_path / "mod.py"
+    path.write_text("a = [y for x in xs for y in x]\n")
+    monkeypatch.chdir(tmp_path)
+    assert main([]) == 1
+    output = capsys.readouterr().out
+    assert f"{path}:1:" in output
+    assert "1 PEP 798 opportunity found" in output
+
+
 def test_main_skips_syntax_errors(
     tmp_path: Path, capsys: pytest.CaptureFixture[str]
 ) -> None: