bpo-46382 dataclass(slots=True) now takes inherited slots into account (GH-31980)

Do not include any members in __slots__ that are already in a base class's __slots__.

1 files changed, 10 insertions, 0 deletions

diff --git a/Doc/library/dataclasses.rst b/Doc/library/dataclasses.rst
index 0f6985f..08568da 100644
--- a/Doc/library/dataclasses.rst
+++ b/Doc/library/dataclasses.rst
@@ -188,6 +188,16 @@ Module contents
 
     .. versionadded:: 3.10
 
+    .. versionchanged:: 3.11
+       If a field name is already included in the ``__slots__``
+       of a base class, it will not be included in the generated ``__slots__``
+       to prevent `overriding them <https://docs.python.org/3/reference/datamodel.html#notes-on-using-slots>`_.
+       Therefore, do not use ``__slots__`` to retrieve the field names of a
+       dataclass. Use :func:`fields` instead.
+       To be able to determine inherited slots,
+       base class ``__slots__`` may be any iterable, but *not* an iterator.
+
+
    ``field``\s may optionally specify a default value, using normal
    Python syntax::