Fix: Filter private stdlib modules and fix --brief output consistency

- Skip private stdlib modules (single underscore) but keep dunder modules like __future__
- Make --brief output only item names, not redundant indented members
- Now --all --brief | wc -l matches --count output
- Add tests for private module filtering

Co-authored-by: Amp <amp@ampcode.com>

Author: heikkitoivonen

scripts/introspect.py

@@ -118,6 +118,9 @@ def build_item_list() -> list[tuple[str, object]]:
     for module_name in get_stdlib_modules():
         if module_name == "builtins" or module_name in skip_modules:
             continue
+        # Skip private modules (single underscore) but keep dunder modules like __future__
+        if module_name.startswith("_") and not module_name.startswith("__"):
+            continue
         try:
             with suppress_stdout():
                 module = importlib.import_module(module_name)
@@ -136,10 +139,10 @@ def build_item_list() -> list[tuple[str, object]]:
 
 def format_module(module: ModuleType, brief: bool) -> list[str]:
     """Format a module's contents."""
-    contents = get_module_contents(module)
     if brief:
-        return [f"  {c}" for c in contents]
+        return []
 
+    contents = get_module_contents(module)
     lines = ["Type: module"]
     if contents:
         lines.append("")
@@ -150,11 +153,10 @@ def format_module(module: ModuleType, brief: bool) -> list[str]:
 
 def format_class(cls: type, brief: bool) -> list[str]:
     """Format a class's methods and attributes."""
-    methods, attributes = get_direct_members(cls)
-
     if brief:
-        return [f"  {name}" for name in (methods + attributes)]
+        return []
 
+    methods, attributes = get_direct_members(cls)
     lines = ["Type: class"]
 
     if methods:

tests/test_introspect.py

@@ -248,6 +248,21 @@ def test_no_duplicate_names(self) -> None:
         names = [name for name, _ in items]
         assert len(names) == len(set(names))
 
+    def test_excludes_private_stdlib_modules(self) -> None:
+        """Private stdlib modules (single underscore) should be excluded."""
+        items = build_item_list()
+        names = [name for name, _ in items]
+        # These are private stdlib modules that should be filtered out
+        private_modules = ["_thread", "_abc", "_collections", "_io"]
+        for mod in private_modules:
+            assert mod not in names, f"Private module {mod} should be excluded"
+
+    def test_includes_dunder_stdlib_modules(self) -> None:
+        """Dunder modules like __future__ should be included."""
+        items = build_item_list()
+        names = [name for name, _ in items]
+        assert "__future__" in names
+
 
 class TestFormatModule:
     """Tests for format_module function."""
@@ -272,14 +287,12 @@ def test_includes_module_contents(self) -> None:
         assert "Counter" in output
         assert "deque" in output
 
-    def test_brief_outputs_names_only(self) -> None:
+    def test_brief_returns_empty_list(self) -> None:
+        """In brief mode, format_module returns empty list (members listed separately)."""
         import collections
 
         lines = format_module(collections, True)
-        output = "\n".join(lines)
-        assert "Type: module" not in output
-        assert "Contents:" not in output
-        assert "Counter" in output
+        assert lines == []
 
 
 class TestFormatClass:
@@ -306,12 +319,10 @@ class EmptyClass:
         lines = format_class(EmptyClass, False)
         assert "(no public direct members)" in lines
 
-    def test_brief_outputs_names_only(self) -> None:
+    def test_brief_returns_empty_list(self) -> None:
+        """In brief mode, format_class returns empty list (members listed separately)."""
         lines = format_class(list, True)
-        output = "\n".join(lines)
-        assert "Type: class" not in output
-        assert "Methods:" not in output
-        assert "append" in output
+        assert lines == []
 
 
 class TestFormatItem: