pylint-dev/astroid v4.3.2

on GitHub

What's new in astroid 4.3.2?

Release date: 2026-09-25

Bug Fixes

• Fix a crash when a namedtuple or Enum type name or field name
  contains str.format markup, as in namedtuple("{0}", "abc"). The name
  is interpolated into an error message that astroid then reformats, so
  building the message raised IndexError. Inference now falls back to its
  default.

  Closes #3199

• Infer a functional TypeVar or NewType whose name is not an identifier
  without splicing that name into the synthesized class source. A crafted value
  such as TypeVar("T(Base): #") no longer breaks out of the identifier
  position to inject bases or a body; the name is assigned to the class verbatim.

  Refs #3217

• Raise InferenceError instead of crashing with IndexError when a class
  uses six.with_metaclass() with no positional metaclass argument, both while
  building the module and when the call is inferred.

  Refs #3248

• ClassDef.slots() no longer crashes on a class that declares a PEP 695
  type parameter literally named __slots__ (e.g. class C[__slots__]:).
  The type parameter's TypeVar node was mistaken for the class's actual
  __slots__ value; slots() now returns None for such classes
  instead of raising AttributeError.

  Refs #3258

• Fix a crash when inferring an f-string or str.format() call whose c format
  spec gets an out-of-range code point, such as f"{-1:c}". These now infer to
  Uninferable, like the %c case fixed in #3254.

  Closes #3301

• The args attribute of an exception instance is now inferred as a tuple
  instance of unknown contents instead of a known empty tuple, so unpacking
  exc.args no longer looks unbalanced.

  Closes pylint-dev/pylint#11312