https://github.com/python/cpython/commit/9cd3c61f385ef65664404cf1caa70b57e5e626c7 commit: 9cd3c61f385ef65664404cf1caa70b57e5e626c7 branch: 3.14 author: Miss Islington (bot) <[email protected]> committer: hugovk <[email protected]> date: 2026-10-31T20:13:34+02:00 summary:
[3.14] Docs: gh-161005: simplify subtype notation in `numbers.rst` (GH-161006) (#161024) Co-authored-by: sai <[email protected]> Co-authored-by: Ned Batchelder <[email protected]> files: M Doc/library/numbers.rst diff --git a/Doc/library/numbers.rst b/Doc/library/numbers.rst index 0ed24b4e6c5225d..a0ef2fcc37ad4ea 100644 --- a/Doc/library/numbers.rst +++ b/Doc/library/numbers.rst @@ -93,7 +93,7 @@ them to the same values. This may be subtle if there are two different extensions of the real numbers. See also :ref:`numeric-hash`. -Adding More Numeric ABCs +Adding more numeric ABCs ~~~~~~~~~~~~~~~~~~~~~~~~ There are, of course, more possible ABCs for numbers, and this would @@ -143,11 +143,12 @@ defined as:: There are 5 different cases for a mixed-type operation on subclasses -of :class:`Complex`. I'll refer to all of the above code that doesn't -refer to ``MyIntegral`` and ``OtherTypeIKnowAbout`` as -"boilerplate". ``a`` will be an instance of ``A``, which is a subtype -of :class:`Complex` (``a : A <: Complex``), and ``b : B <: -Complex``. I'll consider ``a + b``: +of :class:`Complex`. All of the above code that doesn't refer to +``MyIntegral`` and ``OtherTypeIKnowAbout`` is referred to as "boilerplate". + +In this description, ``a`` is an instance of ``A`` and ``b`` is an +instance of ``B``, where ``A`` and ``B`` are both subtypes of :class:`Complex`. +Consider ``a + b``: 1. If ``A`` defines an :meth:`~object.__add__` which accepts ``b``, all is well. @@ -162,13 +163,14 @@ Complex``. I'll consider ``a + b``: 4. If it falls back to the boilerplate, there are no more possible methods to try, so this is where the default implementation should live. -5. If ``B <: A``, Python tries ``B.__radd__`` before +5. If ``B`` is a subtype of ``A``, Python tries ``B.__radd__`` before ``A.__add__``. This is ok, because it was implemented with knowledge of ``A``, so it can handle those instances before delegating to :class:`Complex`. -If ``A <: Complex`` and ``B <: Real`` without sharing any other knowledge, -then the appropriate shared operation is the one involving the built +If ``A`` is a subtype of :class:`Complex` and ``B`` is a subtype of +:class:`Real` without sharing any other knowledge, then the appropriate +shared operation is the one involving the built in :class:`complex`, and both :meth:`~object.__radd__` s land there, so ``a+b == b+a``. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
