Function _transform_attrs

src/attr/_make.py:379–504

Transform all `_CountingAttr`s on a class into `Attribute`s. If *these* is passed, use that and don't look for them on the class. If *collect_by_mro* is True, collect them in the correct MRO order, otherwise use the old -- incorrect -- order. See #428. Return an `_Attributes

(
    cls,
    these,
    auto_attribs,
    kw_only,
    collect_by_mro,
    field_transformer,
)

def _transform_attrs(
    cls,
    these,
    auto_attribs,
    kw_only,
    collect_by_mro,
    field_transformer,
) -> _Attributes:
    """
    Transform all `_CountingAttr`s on a class into `Attribute`s.

    If *these* is passed, use that and don't look for them on the class.

    If *collect_by_mro* is True, collect them in the correct MRO order,
    otherwise use the old -- incorrect -- order.  See #428.

    Return an `_Attributes`.
    """
    cd = cls.__dict__
    anns = _get_annotations(cls)

    if these is not None:
        ca_list = list(these.items())
    elif auto_attribs is True:
        ca_names = {
            name
            for name, attr in cd.items()
            if attr.__class__ is _CountingAttr
        }
        ca_list = []
        annot_names = set()
        for attr_name, type in anns.items():
            if _is_class_var(type):
                continue
            annot_names.add(attr_name)
            a = cd.get(attr_name, NOTHING)

            if a.__class__ is not _CountingAttr:
                a = attrib(a)
            ca_list.append((attr_name, a))

        unannotated = ca_names - annot_names
        if unannotated:
            raise UnannotatedAttributeError(
                "The following `attr.ib`s lack a type annotation: "
                + ", ".join(
                    sorted(unannotated, key=lambda n: cd.get(n).counter)
                )
                + "."
            )
    else:
        ca_list = sorted(
            (
                (name, attr)
                for name, attr in cd.items()
                if attr.__class__ is _CountingAttr
            ),
            key=lambda e: e[1].counter,