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Diffstat (limited to 'Doc/reference/expressions.rst')
| -rw-r--r-- | Doc/reference/expressions.rst | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index 29ef0b7766..5c33ce6f0d 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -390,6 +390,7 @@ on the right hand side of an assignment statement. to sub-generators easy. .. index:: object: generator +.. _generator-methods: Generator-iterator methods ^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -443,12 +444,12 @@ is already executing raises a :exc:`ValueError` exception. .. method:: generator.close() Raises a :exc:`GeneratorExit` at the point where the generator function was - paused. If the generator function then raises :exc:`StopIteration` (by - exiting normally, or due to already being closed) or :exc:`GeneratorExit` (by - not catching the exception), close returns to its caller. If the generator - yields a value, a :exc:`RuntimeError` is raised. If the generator raises any - other exception, it is propagated to the caller. :meth:`close` does nothing - if the generator has already exited due to an exception or normal exit. + paused. If the generator function then exits gracefully, is already closed, + or raises :exc:`GeneratorExit` (by not catching the exception), close + returns to its caller. If the generator yields a value, a + :exc:`RuntimeError` is raised. If the generator raises any other exception, + it is propagated to the caller. :meth:`close` does nothing if the generator + has already exited due to an exception or normal exit. .. index:: single: yield; examples @@ -811,6 +812,20 @@ a class instance: if that method was called. +.. _await: + +Await expression +================ + +Suspend the execution of :term:`coroutine` on an :term:`awaitable` object. +Can only be used inside a :term:`coroutine function`. + +.. productionlist:: + await: ["await"] `primary` + +.. versionadded:: 3.5 + + .. _power: The power operator @@ -820,7 +835,7 @@ The power operator binds more tightly than unary operators on its left; it binds less tightly than unary operators on its right. The syntax is: .. productionlist:: - power: `primary` ["**" `u_expr`] + power: `await` ["**" `u_expr`] Thus, in an unparenthesized sequence of power and unary operators, the operators are evaluated from right to left (this does not constrain the evaluation order @@ -891,8 +906,9 @@ 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 @@ -903,6 +919,13 @@ 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 @@ -1466,13 +1489,16 @@ precedence and have a left-to-right chaining feature as described in the +-----------------------------------------------+-------------------------------------+ | ``+``, ``-`` | Addition and subtraction | +-----------------------------------------------+-------------------------------------+ -| ``*``, ``/``, ``//``, ``%`` | Multiplication, division, remainder | -| | [#]_ | +| ``*``, ``@``, ``/``, ``//``, ``%`` | Multiplication, matrix | +| | multiplication division, | +| | remainder [#]_ | +-----------------------------------------------+-------------------------------------+ | ``+x``, ``-x``, ``~x`` | Positive, negative, bitwise NOT | +-----------------------------------------------+-------------------------------------+ | ``**`` | Exponentiation [#]_ | +-----------------------------------------------+-------------------------------------+ +| ``await`` ``x`` | Await expression | ++-----------------------------------------------+-------------------------------------+ | ``x[index]``, ``x[index:index]``, | Subscription, slicing, | | ``x(arguments...)``, ``x.attribute`` | call, attribute reference | +-----------------------------------------------+-------------------------------------+ |