https://hg.python.org/cpython/rev/313e8fdb0d0c changeset: 102498:313e8fdb0d0c user: Nick Coghlan <ncoghlan@gmail.com> date: Sun Jul 31 12:42:49 2016 +1000 summary: Issue 27366: PEP 487 docs updates - Porting note for type keyword arg handling - __init_subclass__ note regarding metaclass hint files: Doc/reference/datamodel.rst | 7 +++++++ Doc/whatsnew/3.6.rst | 9 +++++++++ 2 files changed, 16 insertions(+), 0 deletions(-) diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -1672,6 +1672,13 @@ The default implementation ``object.__init_subclass__`` does nothing, but raises an error if it is called with any arguments. + .. note:: + + The metaclass hint ``metaclass`` is consumed by the rest of the type + machinery, and is never passed to ``__init_subclass__`` implementations. + The actual metaclass (rather than the explicit hint) can be accessed as + ``type(cls)``. + .. versionadded:: 3.6 diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst --- a/Doc/whatsnew/3.6.rst +++ b/Doc/whatsnew/3.6.rst @@ -759,6 +759,15 @@ <keyword-only_parameter>`. (Contributed by Serhiy Storchaka in :issue:`18726`.) +* As part of :pep:`487`, the handling of keyword arguments passed to + :class:`type` (other than the metaclass hint, ``metaclass``) is now + consistently delegated to :meth:`object.__init_subclass__`. This means that + :meth:`type.__new__` and :meth:`type.__init__` both now accept arbitrary + keyword arguments, but :meth:`object.__init_subclass__` (which is called from + :meth:`type.__new__`) will reject them by default. Custom metaclasses + accepting additional keyword arguments will need to adjust their calls to + :meth:`type.__new__` (whether direct or via :class:`super`) accordingly. + Changes in the C API -------------------- -- Repository URL: https://hg.python.org/cpython