Mailman 3 April 2015 - Python-checkins

peps: pep-0492: Add invalid syntax examples; fix typo.
by yury.selivanov 29 Apr '15

29 Apr '15

https://hg.python.org/peps/rev/d048458307b7 changeset: 5805:d048458307b7 user: Yury Selivanov <yselivanov(a)sprymix.com> date: Wed Apr 29 12:09:19 2015 -0400 summary: pep-0492: Add invalid syntax examples; fix typo. files: pep-0492.txt | 14 ++++++++++++-- 1 files changed, 12 insertions(+), 2 deletions(-) diff --git a/pep-0492.txt b/pep-0492.txt --- a/pep-0492.txt +++ b/pep-0492.txt @@ -171,7 +171,7 @@ from``. The main difference is that *await expressions* do not require parentheses around them most of the times. -Examples: +Valid syntax examples: ================================== ================================== Expression Will be parsed as @@ -187,6 +187,16 @@ ``await foo() + await bar()`` ``(await foo()) + (await bar())`` ================================== ================================== +Invalid syntax examples: + +================================== ================================== +Expression Should be written as +================================== ================================== +``await await coro()`` ``await (await coro())`` +``await -coro()`` ``await (-coro())`` +================================== ================================== + + See `Grammar Updates`_ section for details. @@ -718,7 +728,7 @@ async def foo(): # 2 return (await fut) -This limitation will go away as soon as ``async`` and ``await`` ate +This limitation will go away as soon as ``async`` and ``await`` are proper keywords. Or if it's decided to use a future import for this PEP. -- Repository URL: https://hg.python.org/peps

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Daily reference leaks (293d9964cf6e): sum=3
by solipsis＠pitrou.net 29 Apr '15

29 Apr '15

results for 293d9964cf6e on branch "default" -------------------------------------------- test_functools leaked [0, 0, 3] memory blocks, sum=3 Command line was: ['./python', '-m', 'test.regrtest', '-uall', '-R', '3:3:/home/psf-users/antoine/refleaks/reflogQQ9CxX', '--timeout', '7200']

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Daily reference leaks (293d9964cf6e): sum=3
by solipsis＠pitrou.net 28 Apr '15

28 Apr '15

results for 293d9964cf6e on branch "default" -------------------------------------------- test_functools leaked [0, 0, 3] memory blocks, sum=3 Command line was: ['./python', '-m', 'test.regrtest', '-uall', '-R', '3:3:/home/psf-users/antoine/refleaks/reflogToKr6v', '--timeout', '7200']

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cpython: remove deleted method
by benjamin.peterson 28 Apr '15

28 Apr '15

https://hg.python.org/cpython/rev/293d9964cf6e changeset: 95822:293d9964cf6e user: Benjamin Peterson <benjamin(a)python.org> date: Tue Apr 28 00:04:53 2015 -0400 summary: remove deleted method files: Doc/library/symtable.rst | 4 ---- 1 files changed, 0 insertions(+), 4 deletions(-) diff --git a/Doc/library/symtable.rst b/Doc/library/symtable.rst --- a/Doc/library/symtable.rst +++ b/Doc/library/symtable.rst @@ -71,10 +71,6 @@ Return ``True`` if the block uses ``exec``. - .. method:: has_import_star() - - Return ``True`` if the block uses a starred from-import. - .. method:: get_identifiers() Return a list of names of symbols in this table. -- Repository URL: https://hg.python.org/cpython

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peps: pep-0492: Add one more 'await' syntax example
by yury.selivanov 28 Apr '15

28 Apr '15

https://hg.python.org/peps/rev/4110da8ae758 changeset: 5804:4110da8ae758 user: Yury Selivanov <yselivanov(a)sprymix.com> date: Mon Apr 27 23:24:26 2015 -0400 summary: pep-0492: Add one more 'await' syntax example files: pep-0492.txt | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/pep-0492.txt b/pep-0492.txt --- a/pep-0492.txt +++ b/pep-0492.txt @@ -184,6 +184,7 @@ ``return await coro()`` ``return ( await coro() )`` ``res = await coro() ** 2`` ``res = (await coro()) ** 2`` ``func(a1=await coro(), a2=0)`` ``func(a1=(await coro()), a2=0)`` +``await foo() + await bar()`` ``(await foo()) + (await bar())`` ================================== ================================== See `Grammar Updates`_ section for details. -- Repository URL: https://hg.python.org/peps

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peps: pep-0492: Rename section
by yury.selivanov 28 Apr '15

28 Apr '15

https://hg.python.org/peps/rev/c6cedc4620f9 changeset: 5803:c6cedc4620f9 user: Yury Selivanov <yselivanov(a)sprymix.com> date: Mon Apr 27 23:05:58 2015 -0400 summary: pep-0492: Rename section files: pep-0492.txt | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/pep-0492.txt b/pep-0492.txt --- a/pep-0492.txt +++ b/pep-0492.txt @@ -948,8 +948,8 @@ with the existing grammar. -Why "async for/with" instead of "await for/with" ------------------------------------------------- +Why not "await for" and "await with" +------------------------------------ ``async`` is an adjective, and hence it is a better choice for a *statement qualifier* keyword. ``await for/with`` would imply that -- Repository URL: https://hg.python.org/peps

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peps: pep-0492: Fix markup
by yury.selivanov 28 Apr '15

28 Apr '15

https://hg.python.org/peps/rev/5cc9ca92d9db changeset: 5802:5cc9ca92d9db user: Yury Selivanov <yselivanov(a)sprymix.com> date: Mon Apr 27 23:02:31 2015 -0400 summary: pep-0492: Fix markup files: pep-0492.txt | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/pep-0492.txt b/pep-0492.txt --- a/pep-0492.txt +++ b/pep-0492.txt @@ -171,7 +171,7 @@ from``. The main difference is that *await expressions* do not require parentheses around them most of the times. -Examples:: +Examples: ================================== ================================== Expression Will be parsed as -- Repository URL: https://hg.python.org/peps

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peps: pep-0492: v3; tp_await, noiter, new await syntax, etc
by yury.selivanov 28 Apr '15

28 Apr '15

https://hg.python.org/peps/rev/4f50594e091e changeset: 5801:4f50594e091e user: Yury Selivanov <yselivanov(a)sprymix.com> date: Mon Apr 27 22:40:36 2015 -0400 summary: pep-0492: v3; tp_await, noiter, new await syntax, etc files: pep-0492.txt | 130 ++++++++++++++++++++++++++++++-------- 1 files changed, 101 insertions(+), 29 deletions(-) diff --git a/pep-0492.txt b/pep-0492.txt --- a/pep-0492.txt +++ b/pep-0492.txt @@ -8,7 +8,7 @@ Content-Type: text/x-rst Created: 09-Apr-2015 Python-Version: 3.5 -Post-History: 17-Apr-2015, 21-Apr-2015 +Post-History: 17-Apr-2015, 21-Apr-2015, 27-Apr-2015 Abstract @@ -155,12 +155,40 @@ It is a ``TypeError`` if ``__await__`` returns anything but an iterator. +* Objects defined with CPython C API with a ``tp_await`` function, + returning an iterator (similar to ``__await__`` method). + It is a ``SyntaxError`` to use ``await`` outside of a coroutine. It is a ``TypeError`` to pass anything other than an *awaitable* object to an ``await`` expression. +Syntax of "await" expression +'''''''''''''''''''''''''''' + +``await`` keyword is defined differently from ``yield`` and ``yield +from``. The main difference is that *await expressions* do not require +parentheses around them most of the times. + +Examples:: + +================================== ================================== +Expression Will be parsed as +================================== ================================== +``if await fut: pass`` ``if (await fut): pass`` +``if await fut + 1: pass`` ``if (await fut) + 1: pass`` +``pair = await fut, 'spam'`` ``pair = (await fut), 'spam'`` +``with await fut, open(): pass`` ``with (await fut), open(): pass`` +``await foo()['spam'].baz()()`` ``await ( foo()['spam'].baz()() )`` +``return await coro()`` ``return ( await coro() )`` +``res = await coro() ** 2`` ``res = (await coro()) ** 2`` +``func(a1=await coro(), a2=0)`` ``func(a1=(await coro()), a2=0)`` +================================== ================================== + +See `Grammar Updates`_ section for details. + + Asynchronous Context Managers and "async with" ---------------------------------------------- @@ -487,6 +515,49 @@ unsets the wrapper. +inspect.iscoroutine() and inspect.iscoroutineobject() +----------------------------------------------------- + +Two new functions are added to the ``inspect`` module: + +* ``inspect.iscoroutine(obj)`` returns ``True`` if ``obj`` is a + coroutine object. + +* ``inspect.iscoroutinefunction(obj)`` returns ``True`` is ``obj`` is a + coroutine function. + + +Differences between coroutines and generators +--------------------------------------------- + +A great effort has been made to make sure that coroutines and +generators are separate concepts: + +1. Coroutine objects do not implement ``__iter__`` and ``__next__`` + methods. Therefore they cannot be iterated over or passed to + ``iter()``, ``list()``, ``tuple()`` and other built-ins. They + also cannot be used in a ``for..in`` loop. + +2. ``yield from`` does not accept coroutine objects (unless it is used + in a generator-based coroutine decorated with ``types.coroutine``.) + +3. ``yield from`` does not accept coroutine objects from plain Python + generators (*not* generator-based coroutines.) + +4. ``inspect.isgenerator()`` and ``inspect.isgeneratorfunction()`` + return ``False`` for coroutine objects and coroutine functions. + + +Coroutine objects +----------------- + +Coroutines are based on generators internally, thus they share the +implementation. Similarly to generator objects, coroutine objects have +``throw``, ``send`` and ``close`` methods. ``StopIteration`` and +``GeneratorExit`` play the same role for coroutine objects (although +PEP 479 is enabled by default for coroutines). + + Glossary ======== @@ -500,11 +571,12 @@ details. :Future-like object: - An object with an ``__await__`` method returning an iterator. Can - be consumed by an ``await`` expression in a coroutine. A coroutine - waiting for a Future-like object is suspended until the Future-like - object's ``__await__`` completes, and returns the result. See - `Await Expression`_ for details. + An object with an ``__await__`` method, or a C object with + ``tp_await`` function, returning an iterator. Can be consumed by + an ``await`` expression in a coroutine. A coroutine waiting for a + Future-like object is suspended until the Future-like object's + ``__await__`` completes, and returns the result. See `Await + Expression`_ for details. :Awaitable: A *Future-like* object or a *coroutine object*. See `Await @@ -602,29 +674,16 @@ Grammar changes are also fairly minimal:: - await_expr: AWAIT test - await_stmt: await_expr - decorated: decorators (classdef | funcdef | async_funcdef) async_funcdef: ASYNC funcdef + compound_stmt: (if_stmt | while_stmt | for_stmt | try_stmt | with_stmt + | funcdef | classdef | decorated | async_stmt) + async_stmt: ASYNC (funcdef | with_stmt | for_stmt) - compound_stmt: (if_stmt | while_stmt | for_stmt | try_stmt | - with_stmt | funcdef | classdef | decorated | - async_stmt) - - flow_stmt: (break_stmt | continue_stmt | return_stmt | - raise_stmt | yield_stmt | await_stmt) - - atom: ('(' [yield_expr|await_expr|testlist_comp] ')' | - '[' [testlist_comp] ']' | - '{' [dictorsetmaker] '}' | - NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False’) - - expr_stmt: testlist_star_expr - (augassign (yield_expr|await_expr|testlist) | - ('=' (yield_expr|await_expr|testlist_star_expr))*) + power: atom_expr ['**' factor] + atom_expr: [AWAIT] atom trailer* Transition Period Shortcomings @@ -889,6 +948,15 @@ with the existing grammar. +Why "async for/with" instead of "await for/with" +------------------------------------------------ + +``async`` is an adjective, and hence it is a better choice for a +*statement qualifier* keyword. ``await for/with`` would imply that +something is awaiting for a completion of a ``for`` or ``with`` +statement. + + Why "async def" and not "def async" ----------------------------------- @@ -946,11 +1014,13 @@ * it would not be possible to create an object that works in both ``with`` and ``async with`` statements; -* it would look confusing and would require some implicit magic behind - the scenes in the interpreter; +* it would break backwards compatibility, as nothing prohibits from + returning a Future-like objects from ``__enter__`` and/or + ``__exit__`` in Python <= 3.4; * one of the main points of this proposal is to make coroutines as - simple and foolproof as possible. + simple and foolproof as possible, hence the clear separation of the + protocols. Why not reuse existing "for" and "with" statements @@ -1074,7 +1144,8 @@ 1. New syntax for defining coroutines: ``async def`` and new ``await`` keyword. -2. New ``__await__`` method for Future-like objects. +2. New ``__await__`` method for Future-like objects, and new + ``tp_await`` slot in ``PyTypeObject``. 3. New syntax for asynchronous context managers: ``async with``. And associated protocol with ``__aenter__`` and ``__aexit__`` methods. @@ -1087,7 +1158,8 @@ ``Await``. 6. New functions: ``sys.set_coroutine_wrapper(callback)``, - ``sys.get_coroutine_wrapper()``, and ``types.coroutine(gen)``. + ``sys.get_coroutine_wrapper()``, ``types.coroutine(gen)``, + ``inspect.iscoroutinefunction()``, and ``inspect.iscoroutine()``. 7. New ``CO_COROUTINE`` bit flag for code objects. -- Repository URL: https://hg.python.org/peps

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cpython: remove the concept of an unoptimized function scope from the compiler, since it
by benjamin.peterson 28 Apr '15

28 Apr '15

https://hg.python.org/cpython/rev/3c143f60177c changeset: 95821:3c143f60177c user: Benjamin Peterson <benjamin(a)python.org> date: Mon Apr 27 21:44:22 2015 -0400 summary: remove the concept of an unoptimized function scope from the compiler, since it can't happen anymore files: Include/symtable.h | 5 ----- Lib/symtable.py | 9 ++------- Modules/symtablemodule.c | 3 --- Python/compile.c | 7 ++----- Python/symtable.c | 16 ---------------- 5 files changed, 4 insertions(+), 36 deletions(-) diff --git a/Include/symtable.h b/Include/symtable.h --- a/Include/symtable.h +++ b/Include/symtable.h @@ -43,7 +43,6 @@ PyObject *ste_children; /* list of child blocks */ PyObject *ste_directives;/* locations of global and nonlocal statements */ _Py_block_ty ste_type; /* module, class, or function */ - int ste_unoptimized; /* false if namespace is optimized */ int ste_nested; /* true if block is nested */ unsigned ste_free : 1; /* true if block has free variables */ unsigned ste_child_free : 1; /* true if a child block has free vars, @@ -108,10 +107,6 @@ #define FREE 4 #define CELL 5 -/* The following two names are used for the ste_unoptimized bit field */ -#define OPT_IMPORT_STAR 1 -#define OPT_TOPLEVEL 2 /* top-level names, including eval and exec */ - #define GENERATOR 1 #define GENERATOR_EXPRESSION 2 diff --git a/Lib/symtable.py b/Lib/symtable.py --- a/Lib/symtable.py +++ b/Lib/symtable.py @@ -2,7 +2,7 @@ import _symtable from _symtable import (USE, DEF_GLOBAL, DEF_LOCAL, DEF_PARAM, - DEF_IMPORT, DEF_BOUND, OPT_IMPORT_STAR, SCOPE_OFF, SCOPE_MASK, FREE, + DEF_IMPORT, DEF_BOUND, SCOPE_OFF, SCOPE_MASK, FREE, LOCAL, GLOBAL_IMPLICIT, GLOBAL_EXPLICIT, CELL) import weakref @@ -74,8 +74,7 @@ return self._table.lineno def is_optimized(self): - return bool(self._table.type == _symtable.TYPE_FUNCTION - and not self._table.optimized) + return bool(self._table.type == _symtable.TYPE_FUNCTION) def is_nested(self): return bool(self._table.nested) @@ -87,10 +86,6 @@ """Return true if the scope uses exec. Deprecated method.""" return False - def has_import_star(self): - """Return true if the scope uses import *""" - return bool(self._table.optimized & OPT_IMPORT_STAR) - def get_identifiers(self): return self._table.symbols.keys() diff --git a/Modules/symtablemodule.c b/Modules/symtablemodule.c --- a/Modules/symtablemodule.c +++ b/Modules/symtablemodule.c @@ -84,9 +84,6 @@ PyModule_AddIntConstant(m, "TYPE_CLASS", ClassBlock); PyModule_AddIntConstant(m, "TYPE_MODULE", ModuleBlock); - PyModule_AddIntMacro(m, OPT_IMPORT_STAR); - PyModule_AddIntMacro(m, OPT_TOPLEVEL); - PyModule_AddIntMacro(m, LOCAL); PyModule_AddIntMacro(m, GLOBAL_EXPLICIT); PyModule_AddIntMacro(m, GLOBAL_IMPLICIT); diff --git a/Python/compile.c b/Python/compile.c --- a/Python/compile.c +++ b/Python/compile.c @@ -2753,8 +2753,7 @@ optype = OP_FAST; break; case GLOBAL_IMPLICIT: - if (c->u->u_ste->ste_type == FunctionBlock && - !c->u->u_ste->ste_unoptimized) + if (c->u->u_ste->ste_type == FunctionBlock) optype = OP_GLOBAL; break; case GLOBAL_EXPLICIT: @@ -4185,9 +4184,7 @@ int flags = 0; Py_ssize_t n; if (ste->ste_type == FunctionBlock) { - flags |= CO_NEWLOCALS; - if (!ste->ste_unoptimized) - flags |= CO_OPTIMIZED; + flags |= CO_NEWLOCALS | CO_OPTIMIZED; if (ste->ste_nested) flags |= CO_NESTED; if (ste->ste_generator) diff --git a/Python/symtable.c b/Python/symtable.c --- a/Python/symtable.c +++ b/Python/symtable.c @@ -47,7 +47,6 @@ ste->ste_directives = NULL; ste->ste_type = block; - ste->ste_unoptimized = 0; ste->ste_nested = 0; ste->ste_free = 0; ste->ste_varargs = 0; @@ -113,7 +112,6 @@ {"symbols", T_OBJECT, OFF(ste_symbols), READONLY}, {"varnames", T_OBJECT, OFF(ste_varnames), READONLY}, {"children", T_OBJECT, OFF(ste_children), READONLY}, - {"optimized",T_INT, OFF(ste_unoptimized), READONLY}, {"nested", T_INT, OFF(ste_nested), READONLY}, {"type", T_INT, OFF(ste_type), READONLY}, {"lineno", T_INT, OFF(ste_lineno), READONLY}, @@ -271,7 +269,6 @@ } st->st_top = st->st_cur; - st->st_cur->ste_unoptimized = OPT_TOPLEVEL; switch (mod->kind) { case Module_kind: seq = mod->v.Module.body; @@ -1245,21 +1242,9 @@ break; case Import_kind: VISIT_SEQ(st, alias, s->v.Import.names); - /* XXX Don't have the lineno available inside - visit_alias */ - if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno) { - st->st_cur->ste_opt_lineno = s->lineno; - st->st_cur->ste_opt_col_offset = s->col_offset; - } break; case ImportFrom_kind: VISIT_SEQ(st, alias, s->v.ImportFrom.names); - /* XXX Don't have the lineno available inside - visit_alias */ - if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno) { - st->st_cur->ste_opt_lineno = s->lineno; - st->st_cur->ste_opt_col_offset = s->col_offset; - } break; case Global_kind: { int i; @@ -1615,7 +1600,6 @@ Py_DECREF(store_name); return 0; } - st->st_cur->ste_unoptimized |= OPT_IMPORT_STAR; Py_DECREF(store_name); return 1; } -- Repository URL: https://hg.python.org/cpython

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cpython (3.4): Issue #21354: PyCFunction_New function is exposed by python DLL again.
by andrew.svetlov 27 Apr '15

27 Apr '15

https://hg.python.org/cpython/rev/69951573cb0e changeset: 95819:69951573cb0e branch: 3.4 parent: 95817:5850f0c17c34 user: Andrew Svetlov <andrew.svetlov(a)gmail.com> date: Mon Apr 27 17:48:50 2015 +0300 summary: Issue #21354: PyCFunction_New function is exposed by python DLL again. files: Misc/NEWS | 2 ++ Objects/methodobject.c | 2 +- 2 files changed, 3 insertions(+), 1 deletions(-) diff --git a/Misc/NEWS b/Misc/NEWS --- a/Misc/NEWS +++ b/Misc/NEWS @@ -34,6 +34,8 @@ - Issue #24044: Fix possible null pointer dereference in list.sort in out of memory conditions. +- Issue #21354: PyCFunction_New function is exposed by python DLL again. + Library ------- diff --git a/Objects/methodobject.c b/Objects/methodobject.c --- a/Objects/methodobject.c +++ b/Objects/methodobject.c @@ -16,7 +16,7 @@ /* undefine macro trampoline to PyCFunction_NewEx */ #undef PyCFunction_New -PyObject * +PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *ml, PyObject *self) { return PyCFunction_NewEx(ml, self, NULL); -- Repository URL: https://hg.python.org/cpython

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