Remove colorless theme monkeypatchfor argparse bug in 3.15.0b1 (#1674)

3.15.0b2 is out and available now in both uv and GitHub Actions.

Author: tleonhardt

cmd2/argparse_utils.py

@@ -423,30 +423,6 @@ def _validate_completion_callable(self: argparse.Action, value: Any) -> Any:
 register_argparse_argument_parameter("nargs_range")
 register_argparse_argument_parameter("suppress_tab_hint")
 
-############################################################################################################
-# Workaround for Python 3.15.0b1 argparse bug
-# _ColorlessTheme.__getattr__ incorrectly returns "" for non-public attributes, which breaks
-# protocols like copy.deepcopy().
-############################################################################################################
-
-if sys.version_info >= (3, 15):
-
-    def _ColorlessTheme_getattr(  # noqa: N802
-        _self: argparse._ColorlessTheme,  # type: ignore[name-defined]
-        name: str,
-    ) -> Any:
-        """Patched __getattr__ that allows non-public lookups to fail correctly.
-
-        This matches the implementation in CPython for their next release.
-        """
-        if name.startswith("_"):
-            raise AttributeError(name)
-        return ""
-
-    # If the bug still exists, then install the patch.
-    if getattr(argparse._ColorlessTheme(), "__deepcopy__", None) == "":  # type: ignore[attr-defined]
-        argparse._ColorlessTheme.__getattr__ = _ColorlessTheme_getattr  # type: ignore[attr-defined]
-
 
 ############################################################################################################
 # Patch _ActionsContainer.add_argument to support more arguments

tests/test_argparse_utils.py

@@ -863,22 +863,3 @@ def test_deprecated_subcommand() -> None:
     # Verify it was removed from _deprecated set
     assert "old" not in subparsers_action._deprecated  # type: ignore[attr-defined]
     assert "old_alias" not in subparsers_action._deprecated  # type: ignore[attr-defined]
-
-
-@pytest.mark.skipif(
-    sys.version_info < (3, 15),
-    reason="_ColorlessTheme only exists in 3.15+",
-)
-def test_colorless_theme_monkeypatch() -> None:
-    """Test the _ColorlessTheme.__getattr__ monkey patch."""
-
-    # If this assertion fails, then the bug no longer exists and our patch wasn't installed.
-    # We can remove the patch function and this test.
-    assert argparse._ColorlessTheme.__getattr__ == argparse_utils._ColorlessTheme_getattr
-
-    # Our patch raises an Attribute error for non-public.
-    with pytest.raises(AttributeError):
-        getattr(argparse._ColorlessTheme(), "_fake")  # noqa: B009
-
-    with pytest.raises(AttributeError):
-        getattr(argparse._ColorlessTheme(), "__deepcopy__")  # noqa: B009