https://github.com/python/cpython/commit/2713c2abc8d0f30cd0060cd307bb4ec92f1f04bf commit: 2713c2abc8d0f30cd0060cd307bb4ec92f1f04bf branch: main author: Gouvernathor <[email protected]> committer: erlend-aasland <[email protected]> date: 2024-03-01T16:51:47+01:00 summary:
gh-104219: Document that idunders can return NotImplemented (#104220) Co-authored-by: C.A.M. Gerlach <[email protected]> Co-authored-by: Jelle Zijlstra <[email protected]> files: M Doc/reference/datamodel.rst diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst index 1aef2668e82cd1..82106a41c4c4ed 100644 --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -3044,10 +3044,12 @@ left undefined. (``+=``, ``-=``, ``*=``, ``@=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``, ``>>=``, ``&=``, ``^=``, ``|=``). These methods should attempt to do the operation in-place (modifying *self*) and return the result (which could be, - but does not have to be, *self*). If a specific method is not defined, the + but does not have to be, *self*). If a specific method is not defined, or if + that method returns :data:`NotImplemented`, the augmented assignment falls back to the normal methods. For instance, if *x* is an instance of a class with an :meth:`__iadd__` method, ``x += y`` is - equivalent to ``x = x.__iadd__(y)`` . Otherwise, ``x.__add__(y)`` and + equivalent to ``x = x.__iadd__(y)`` . If :meth:`__iadd__` does not exist, or if ``x.__iadd__(y)`` + returns :data:`!NotImplemented`, ``x.__add__(y)`` and ``y.__radd__(x)`` are considered, as with the evaluation of ``x + y``. In certain situations, augmented assignment can result in unexpected errors (see :ref:`faq-augmented-assignment-tuple-error`), but this behavior is in fact _______________________________________________ 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]
