What's New in astroid 4.0.0?

Release date: 2025-10-05

• Support constraints from ternary expressions in inference.

  Closes pylint-dev/pylint#9729

• Handle deprecated bool(NotImplemented) cast in const nodes.

• Add support for boolean truthiness constraints (x, not x) in inference.

  Closes pylint-dev/pylint#9515

• Fix false positive invalid-name on attrs classes with ClassVar annotated variables.

  Closes pylint-dev/pylint#10525

• Prevent crash when parsing deeply nested parentheses causing MemoryError in python's built-in ast.

  Closes #2643

• Fix crash when inferring namedtuple with invalid field name looking like f-string formatting.

  Closes #2519

• Fix false positive no-member in except * handler.

  Closes pylint-dev/pylint#9056

• Fix crash when comparing invalid dict literal

  Closes #2522

• Removed internal functions infer_numpy_member, name_looks_like_numpy_member, and
  attribute_looks_like_numpy_member from astroid.brain.brain_numpy_utils.

• To alleviate circular imports, the manager argument to AstroidBuilder() is now required.

• Constants now have a parent of nodes.SYNTHETIC_ROOT.

• Fix crashes with large positive and negative list multipliers.

  Closes #2521
  Closes #2523

• Fix precedence of path arg in modpath_from_file_with_callback to be higher than sys.path

• Following a deprecation period, the future argument was removed from statement() and frame().

• Improve consistency of JoinedStr inference by not raising InferenceError and
  returning either Uninferable or a fully resolved Const.

  Closes #2621

• Fix crash when typing._alias() call is missing arguments.

  Closes #2513

• Remove support for Python 3.9 (and constant PY310_PLUS).

• Include subclasses of standard property classes as property decorators

  Closes #10377

• Modify astroid.bases and tests.test_nodes to reflect that enum.property was added in Python 3.11, not 3.10

• Fix incorrect result in _get_relative_base_path when the target directory name starts with the base path

  Closes #2608

• The brain for nose was dropped. nose has been deprecated for 10 years and the brain required some maintenance.

  Refs #2765

• Fix a crash when the root of a node is not a module but is unknown.

  Closes #2672

• Add basic support for ast.TemplateStr and ast.Interpolationadded in Python 3.14.

  Refs #2789

• Add support for type parameter defaults added in Python 3.13.

• Improve as_string() representation for TypeVar, ParamSpec and TypeVarTuple nodes, as well as
  type parameter in ClassDef, FuncDef and TypeAlias nodes (PEP 695).

• Astroid now correctly supports the exceptions attribute of ExceptionGroup.

  Closes pylint-dev/pylint#8985
  Closes pylint-dev/pylint#10558

• Deprecate importing node classes from astroid directly. This will be removed in v5.
  It's recommended to import them from astroid.nodes instead.

  Refs #2837