cpython: b6ee02acaae9 (original) (raw)

Mercurial > cpython

changeset 93615:b6ee02acaae9

Issue22780: reword NotImplemented docs to emphasise should

Ethan Furman ethan@stoneleaf.us
date	Wed, 26 Nov 2014 21:17:53 -0800
parents	d502b5d60e00(current diff)ebb8865dcf54(diff)
children	1c97f373fe49
files	Doc/library/constants.rst Doc/reference/datamodel.rst
diffstat	3 files changed, 25 insertions(+), 4 deletions(-)[+] [-] Doc/library/constants.rst 20 Doc/library/numbers.rst 2 Doc/reference/datamodel.rst 7

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line diff

--- a/Doc/library/constants.rst +++ b/Doc/library/constants.rst @@ -26,9 +26,23 @@ A small number of constants live in the .. data:: NotImplemented

Special value which should be returned by the special methods
(:meth:__eq__, :meth:__lt__, :meth:__add__, etc.) to indicate
that the operation is not implemented with respect to the other type.

Special value which should be returned by the binary special methods
(e.g. :meth:__eq__, :meth:__lt__, :meth:__add__, :meth:__rsub__,
etc.) to indicate that the operation is not implemented with respect to
the other type; may be returned by the in-place binary special methods
(e.g. :meth:__imul__, :meth:__iand__, etc.) for the same purpose.
Its truth value is true. +

+.. note:: +

When NotImplemented is returned, the interpreter will then try the
reflected operation on the other type, or some other fallback, depending
on the operator. If all attempted operations return NotImplemented, the
interpreter will raise an appropriate exception. +
See
:ref:implementing-the-arithmetic-operations
for more details.

.. data:: Ellipsis

--- a/Doc/library/numbers.rst +++ b/Doc/library/numbers.rst @@ -110,6 +110,8 @@ those. You can add MyFoo between :cl MyFoo.register(Real) +.. _implementing-the-arithmetic-operations: + Implementing the arithmetic operations

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

--- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -154,11 +154,16 @@ NotImplemented This type has a single value. There is a single object with this value. This object is accessed through the built-in name NotImplemented. Numeric methods

and rich comparison methods may return this value if they do not implement the

and rich comparison methods should return this value if they do not implement the operation for the operands provided. (The interpreter will then try the reflected operation, or some other fallback, depending on the operator.) Its truth value is true.
See
:ref:implementing-the-arithmetic-operations
for more details. +

+ Ellipsis .. index:: object: Ellipsis