mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-11-02 03:01:58 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 15

PEP 465: a dedicated infix operator for matrix multiplication (closes #21176)

Browse source
This commit is contained in:
Benjamin Peterson 2014-04-09 23:55:56 -04:00
parent 2aad6ef774
commit d51374ed78
42 changed files with 803 additions and 442 deletions
Download patch file Download diff file Expand all files Collapse all files

60
Doc/reference/datamodel.rst
View file

@ -1970,6 +1970,7 @@ left undefined.
.. method:: object.__add__(self, other)
object.__sub__(self, other)
object.__mul__(self, other)
object.__matmul__(self, other)
object.__truediv__(self, other)
object.__floordiv__(self, other)
object.__mod__(self, other)
@ -1986,15 +1987,16 @@ left undefined.
builtin: pow
builtin: pow
These methods are called to implement the binary arithmetic operations (``+``,
``-``, ``*``, ``/``, ``//``, ``%``, :func:`divmod`, :func:`pow`, ``**``, ``<<``,
``>>``, ``&``, ``^``, ``|``). For instance, to evaluate the expression
``x + y``, where *x* is an instance of a class that has an :meth:`__add__`
method, ``x.__add__(y)`` is called. The :meth:`__divmod__` method should be the
equivalent to using :meth:`__floordiv__` and :meth:`__mod__`; it should not be
related to :meth:`__truediv__`. Note that :meth:`__pow__` should be defined
to accept an optional third argument if the ternary version of the built-in
:func:`pow` function is to be supported.
These methods are called to implement the binary arithmetic operations
(``+``, ``-``, ``*``, ``@``, ``/``, ``//``, ``%``, :func:`divmod`,
:func:`pow`, ``**``, ``<<``, ``>>``, ``&``, ``^``, ``|``). For instance, to
evaluate the expression ``x + y``, where *x* is an instance of a class that
has an :meth:`__add__` method, ``x.__add__(y)`` is called. The
:meth:`__divmod__` method should be the equivalent to using
:meth:`__floordiv__` and :meth:`__mod__`; it should not be related to
:meth:`__truediv__`. Note that :meth:`__pow__` should be defined to accept
an optional third argument if the ternary version of the built-in :func:`pow`
function is to be supported.
If one of those methods does not support the operation with the supplied
arguments, it should return ``NotImplemented``.
@ -2003,6 +2005,7 @@ left undefined.
.. method:: object.__radd__(self, other)
object.__rsub__(self, other)
object.__rmul__(self, other)
object.__rmatmul__(self, other)
object.__rtruediv__(self, other)
object.__rfloordiv__(self, other)
object.__rmod__(self, other)
@ -2018,14 +2021,14 @@ left undefined.
builtin: divmod
builtin: pow
These methods are called to implement the binary arithmetic operations (``+``,
``-``, ``*``, ``/``, ``//``, ``%``, :func:`divmod`, :func:`pow`, ``**``,
``<<``, ``>>``, ``&``, ``^``, ``|``) with reflected (swapped) operands.
These functions are only called if the left operand does not support the
corresponding operation and the operands are of different types. [#]_ For
instance, to evaluate the expression ``x - y``, where *y* is an instance of
a class that has an :meth:`__rsub__` method, ``y.__rsub__(x)`` is called if
``x.__sub__(y)`` returns *NotImplemented*.
These methods are called to implement the binary arithmetic operations
(``+``, ``-``, ``*``, ``@``, ``/``, ``//``, ``%``, :func:`divmod`,
:func:`pow`, ``**``, ``<<``, ``>>``, ``&``, ``^``, ``|``) with reflected
(swapped) operands. These functions are only called if the left operand does
not support the corresponding operation and the operands are of different
types. [#]_ For instance, to evaluate the expression ``x - y``, where *y* is
an instance of a class that has an :meth:`__rsub__` method, ``y.__rsub__(x)``
is called if ``x.__sub__(y)`` returns *NotImplemented*.
.. index:: builtin: pow
@ -2043,6 +2046,7 @@ left undefined.
.. method:: object.__iadd__(self, other)
object.__isub__(self, other)
object.__imul__(self, other)
object.__imatmul__(self, other)
object.__itruediv__(self, other)
object.__ifloordiv__(self, other)
object.__imod__(self, other)
@ -2054,17 +2058,17 @@ left undefined.
object.__ior__(self, other)
These methods are called to implement the augmented arithmetic assignments
(``+=``, ``-=``, ``*=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``, ``>>=``,
``&=``, ``^=``, ``|=``). 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 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 ``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 part of the data model.
(``+=``, ``-=``, ``*=``, ``@=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``,
``>>=``, ``&=``, ``^=``, ``|=``). 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
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
``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
part of the data model.
.. method:: object.__neg__(self)

17
Doc/reference/expressions.rst
View file

@ -892,8 +892,9 @@ from the power operator, there are only two levels, one for multiplicative
operators and one for additive operators:
.. productionlist::
m_expr: `u_expr` | `m_expr` "*" `u_expr` | `m_expr` "//" `u_expr` | `m_expr` "/" `u_expr`
: | `m_expr` "%" `u_expr`
m_expr: `u_expr` | `m_expr` "*" `u_expr` | `m_expr` "@" `m_expr` |
: `m_expr` "//" `u_expr`| `m_expr` "/" `u_expr` |
: `m_expr` "%" `u_expr`
a_expr: `m_expr` | `a_expr` "+" `m_expr` | `a_expr` "-" `m_expr`
.. index:: single: multiplication
@ -904,6 +905,13 @@ the other must be a sequence. In the former case, the numbers are converted to a
common type and then multiplied together. In the latter case, sequence
repetition is performed; a negative repetition factor yields an empty sequence.
.. index:: single: matrix multiplication
The ``@`` (at) operator is intended to be used for matrix multiplication. No
builtin Python types implement this operator.
.. versionadded:: 3.5
.. index::
exception: ZeroDivisionError
single: division
@ -1346,8 +1354,9 @@ groups from right to left).
+-----------------------------------------------+-------------------------------------+
| ``+``, ``-`` | Addition and subtraction |
+-----------------------------------------------+-------------------------------------+
| ``*``, ``/``, ``//``, ``%`` | Multiplication, division, remainder |
| | [#]_ |
| ``*``, ``@``, ``/``, ``//``, ``%`` | Multiplication, matrix |
| | multiplication division, |
| | remainder [#]_ |
+-----------------------------------------------+-------------------------------------+
| ``+x``, ``-x``, ``~x`` | Positive, negative, bitwise NOT |
+-----------------------------------------------+-------------------------------------+

2
Doc/reference/simple_stmts.rst
View file

@ -267,7 +267,7 @@ operation and an assignment statement:
.. productionlist::
augmented_assignment_stmt: `augtarget` `augop` (`expression_list` | `yield_expression`)
augtarget: `identifier` | `attributeref` | `subscription` | `slicing`
augop: "+=" | "-=" | "*=" | "/=" | "//=" | "%=" | "**="
augop: "+=" | "-=" | "*=" | "@=" | "/=" | "//=" | "%=" | "**="
: | ">>=" | "<<=" | "&=" | "^=" | "|="
(See section :ref:`primaries` for the syntax definitions for the last three