Function get_class_annotations

src/msgspec/_utils.py:109–150

Get the annotations for a class. This is similar to ``typing.get_type_hints``, except: - We maintain it - It leaves extras like ``Annotated``/``ClassVar`` alone - It resolves any parametrized generics in the class mro. The returned mapping may still include ``TypeVar`` values

(obj)

def get_class_annotations(obj):
    """Get the annotations for a class.

    This is similar to ``typing.get_type_hints``, except:

    - We maintain it
    - It leaves extras like ``Annotated``/``ClassVar`` alone
    - It resolves any parametrized generics in the class mro. The returned
      mapping may still include ``TypeVar`` values, but those should be treated
      as their unparametrized variants (i.e. equal to ``Any`` for the common case).

    Note that this function doesn't check that Generic types are being used
    properly - invalid uses of `Generic` may slip through without complaint.

    The assumption here is that the user is making use of a static analysis
    tool like ``mypy``/``pyright`` already, which would catch misuse of these
    APIs.
    """
    hints = {}
    mro, typevar_mappings = _get_class_mro_and_typevar_mappings(obj)

    for cls in mro:
        if cls in (typing.Generic, object):
            continue

        mapping = typevar_mappings.get(cls)
        cls_locals = dict(vars(cls))
        cls_globals = getattr(sys.modules.get(cls.__module__, None), "__dict__", {})

        ann = _get_class_annotations(cls)
        for name, value in ann.items():
            if name in hints:
                continue
            if isinstance(value, str):
                value = _forward_ref(value)
            value = _eval_type(value, cls_locals, cls_globals)
            if mapping is not None:
                value = _apply_params(value, mapping)
            if value is None:
                value = type(None)
            hints[name] = value
    return hints


# A mapping from a type annotation (or annotation __origin__) to the concrete