Mailman 3 April 2012 - Python-checkins

Daily reference leaks (d4fd58fff480): sum=0
by solipsis＠pitrou.net April 30, 2012

April 30, 2012

results for d4fd58fff480 on branch "default" -------------------------------------------- test_support leaked [0, -1, 1] references, sum=0 Command line was: ['./python', '-m', 'test.regrtest', '-uall', '-R', '3:3:/home/antoine/cpython/refleaks/reflogkVmW2m', '-x']

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cpython (merge default -> default): merge
by victor.stinner April 30, 2012

April 30, 2012

http://hg.python.org/cpython/rev/7319430a291d changeset: 76659:7319430a291d parent: 76658:08b54c635586 parent: 76656:d4fd58fff480 user: Victor Stinner <victor.stinner(a)gmail.com> date: Mon Apr 30 05:24:04 2012 +0200 summary: merge files: Doc/whatsnew/3.3.rst | 122 +++++++++++++++++++++++++++++++ Lib/functools.py | 21 ++-- 2 files changed, 133 insertions(+), 10 deletions(-) diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst --- a/Doc/whatsnew/3.3.rst +++ b/Doc/whatsnew/3.3.rst @@ -452,6 +452,89 @@ '<function C.D.meth at 0x7f46b9fe31e0>' +Using importlib as the Implementation of Import +=============================================== +:issue:`2377` - Replace __import__ w/ importlib.__import__ +:issue:`13959` - Re-implement parts of :mod:`imp` in pure Python +:issue:`14605` - Make import machinery explicit +:issue:`14646` - Require loaders set __loader__ and __package__ + +(Written by Brett Cannon) + +The :func:`__import__` function is now powered by :func:`importlib.__import__`. +This work leads to the completion of "phase 2" of :pep:`302`. There are +multiple benefits to this change. First, it has allowed for more of the +machinery powering import to be exposed instead of being implicit and hidden +within the C code. It also provides a single implementation for all Python VMs +supporting Python 3.3 to use, helping to end any VM-specific deviations in +import semantics. And finally it eases the maintenance of import, allowing for +future growth to occur. + +For the common user, this change should result in no visible change in +semantics. Any possible changes required in one's code to handle this change +should read the `Porting Python code`_ section of this document to see what +needs to be changed, but it will only affect those that currently manipulate +import or try calling it programmatically. + +New APIs +-------- +One of the large benefits of this work is the exposure of what goes into +making the import statement work. That means the various importers that were +once implicit are now fully exposed as part of the :mod:`importlib` package. + +In terms of finders, * :class:`importlib.machinery.FileFinder` exposes the +mechanism used to search for source and bytecode files of a module. Previously +this class was an implicit member of :attr:`sys.path_hooks`. + +For loaders, the new abstract base class :class:`importlib.abc.FileLoader` helps +write a loader that uses the file system as the storage mechanism for a module's +code. The loader for source files +(:class:`importlib.machinery.SourceFileLoader`), sourceless bytecode files +(:class:`importlib.machinery.SourcelessFileLoader`), and extension modules +(:class:`importlib.machinery.ExtensionFileLoader`) are now available for +direct use. + +:exc:`ImportError` now has ``name`` and ``path`` attributes which are set when +there is relevant data to provide. The message for failed imports will also +provide the full name of the module now instead of just the tail end of the +module's name. + +The :func:`importlib.invalidate_caches` function will now call the method with +the same name on all finders cached in :attr:`sys.path_importer_cache` to help +clean up any stored state as necessary. + +Visible Changes +--------------- +[For potential required changes to code, see the `Porting Python code`_ +section] + +Beyond the expanse of what :mod:`importlib` now exposes, there are other +visible changes to import. The biggest is that :attr:`sys.meta_path` and +:attr:`sys.path_hooks` now store all of the finders used by import explicitly. +Previously the finders were implicit and hidden within the C code of import +instead of being directly exposed. This means that one can now easily remove or +change the order of the various finders to fit one's needs. + +Another change is that all modules have a ``__loader__`` attribute, storing the +loader used to create the module. :pep:`302` has been updated to make this +attribute mandatory for loaders to implement, so in the future once 3rd-party +loaders have been updated people will be able to rely on the existence of the +attribute. Until such time, though, import is setting the module post-load. + +Loaders are also now expected to set the ``__package__`` attribute from +:pep:`366`. Once again, import itself is already setting this on all loaders +from :mod:`importlib` and import itself is setting the attribute post-load. + +``None`` is now inserted into :attr:`sys.path_importer_cache` when no finder +can be found on :attr:`sys.path_hooks`. Since :class:`imp.NullImporter` is not +directly exposed on :attr:`sys.path_hooks` it could no longer be relied upon to +always be available to use as a value representing no finder found. + +All other changes relate to semantic changes which should be taken into +consideration when updating code for Python 3.3, and thus should be read about +in the `Porting Python code`_ section of this document. + + Other Language Changes ====================== @@ -1283,6 +1366,45 @@ timestamp is out of range. :exc:`OSError` is now raised if C functions :c:func:`gmtime` or :c:func:`localtime` failed. +* The default finders used by import now utilize a cache of what is contained + within a specific directory. If you create a Python source file or sourceless + bytecode file, make sure to call :func:`importlib.invalidate_caches` to clear + out the cache for the finders to notice the new file. + +* :exc:`ImportError` now uses the full name of the module that was attemped to + be imported. Doctests that check ImportErrors' message will need to be + updated to use the full name of the module instead of just the tail of the + name. + +* The **index** argument to :func:`__import__` now defaults to 0 instead of -1 + and no longer support negative values. It was an oversight when :pep:`328` was + implemented that the default value remained -1. If you need to continue to + perform a relative import followed by an absolute import, then perform the + relative import using an index of 1, followed by another import using an + index of 0. It is preferred, though, that you use + :func:`importlib.import_module` rather than call :func:`__import__` directly. + +* :func:`__import__` no longer allows one to use an index value other than 0 + for top-level modules. E.g. ``__import__('sys', level=1)`` is now an error. + +* Because :attr:`sys.meta_path` and :attr:`sys.path_hooks` now have finders on + them by default, you will most likely want to use :meth:`list.insert` instead + of :meth:`list.append` to add to those lists. + +* Because ``None`` is now inserted into :attr:`sys.path_importer_cache`, if you + are clearing out entries in the dictionary of paths that do not have a + finder, you will need to remove keys paired with values of ``None`` **and** + :class:`imp.NullImporter` to be backwards-compatible. This will need to extra + overhead on older versions of Python that re-insert ``None`` into + :attr:`sys.path_importer_cache` where it repesents the use of implicit + finders, but semantically it should not change anything. + +* :meth:`importlib.abc.SourceLoader.path_mtime` is now deprecated in favour of + :meth:`importlib.abc.SourceLoader.path_stats` as bytecode files now store + both the modification time and size of the source file the bytecode file was + compiled from. + + Porting C code -------------- diff --git a/Lib/functools.py b/Lib/functools.py --- a/Lib/functools.py +++ b/Lib/functools.py @@ -168,15 +168,14 @@ # to allow the implementation to change (including a possible C version). # Constants shared by all lru cache instances: - kwd_mark = (object(),) # separate positional and keyword args - sentinel = object() # unique object used to signal cache misses - _len = len # localize the global len() function + kwd_mark = (object(),) # separate positional and keyword args + sentinel = object() # unique object used to signal cache misses PREV, NEXT, KEY, RESULT = 0, 1, 2, 3 # names for the link fields def decorating_function(user_function): cache = {} - hits = misses = 0 + hits = misses = currsize = 0 cache_get = cache.get # bound method to lookup a key or return None lock = Lock() # because linkedlist updates aren't threadsafe root = [] # root of the circular doubly linked list @@ -209,7 +208,7 @@ def wrapper(*args, **kwds): # simple caching without ordering or size limit - nonlocal hits, misses + nonlocal hits, misses, currsize key = make_key(args, kwds, typed) if kwds or typed else args result = cache_get(key, sentinel) if result is not sentinel: @@ -218,13 +217,14 @@ result = user_function(*args, **kwds) cache[key] = result misses += 1 + currsize += 1 return result else: def wrapper(*args, **kwds): # size limited caching that tracks accesses by recency - nonlocal root, hits, misses + nonlocal root, hits, misses, currsize key = make_key(args, kwds, typed) if kwds or typed else args with lock: link = cache_get(key) @@ -241,11 +241,12 @@ return result result = user_function(*args, **kwds) with lock: - if _len(cache) < maxsize: + if currsize < maxsize: # put result in a new link at the front of the queue last = root[PREV] link = [last, root, key, result] cache[key] = last[NEXT] = root[PREV] = link + currsize += 1 else: # use root to store the new key and result root[KEY] = key @@ -261,15 +262,15 @@ def cache_info(): """Report cache statistics""" with lock: - return _CacheInfo(hits, misses, maxsize, len(cache)) + return _CacheInfo(hits, misses, maxsize, currsize) def cache_clear(): """Clear the cache and cache statistics""" - nonlocal hits, misses + nonlocal hits, misses, currsize with lock: cache.clear() root[:] = [root, root, None, None] - hits = misses = 0 + hits = misses = currsize = 0 wrapper.cache_info = cache_info wrapper.cache_clear = cache_clear -- Repository URL: http://hg.python.org/cpython

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cpython: Issue #14687: Avoid an useless duplicated string in PyUnicode_Format()
by victor.stinner April 30, 2012

April 30, 2012

http://hg.python.org/cpython/rev/08b54c635586 changeset: 76658:08b54c635586 user: Victor Stinner <victor.stinner(a)gmail.com> date: Mon Apr 30 05:21:52 2012 +0200 summary: Issue #14687: Avoid an useless duplicated string in PyUnicode_Format() files: Objects/unicodeobject.c | 22 +++++++++------------- 1 files changed, 9 insertions(+), 13 deletions(-) diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -14051,20 +14051,16 @@ } } /* Copy all characters, preserving len */ - if (temp != NULL) { - assert(pbuf == PyUnicode_DATA(temp)); + if (pindex == 0 && len == PyUnicode_GET_LENGTH(temp)) { + r = _PyAccu_Accumulate(&acc, temp); + } + else { v = PyUnicode_Substring(temp, pindex, pindex + len); - } - else { - const char *p = (const char *) pbuf; - assert(pbuf != NULL); - p += kind * pindex; - v = PyUnicode_FromKindAndData(kind, p, len); - } - if (v == NULL) - goto onError; - r = _PyAccu_Accumulate(&acc, v); - Py_DECREF(v); + if (v == NULL) + goto onError; + r = _PyAccu_Accumulate(&acc, v); + Py_DECREF(v); + } if (r) goto onError; if (width > len && repeat_accumulate(&acc, blank, width - len)) -- Repository URL: http://hg.python.org/cpython

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cpython: Issue #14687: Cleanup PyUnicode_Format()
by victor.stinner April 30, 2012

April 30, 2012

http://hg.python.org/cpython/rev/42fbb4f9b540 changeset: 76657:42fbb4f9b540 parent: 76654:ad3d6010379b user: Victor Stinner <victor.stinner(a)gmail.com> date: Mon Apr 30 05:19:21 2012 +0200 summary: Issue #14687: Cleanup PyUnicode_Format() files: Objects/unicodeobject.c | 86 ++++++++++------------------ 1 files changed, 30 insertions(+), 56 deletions(-) diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -6986,8 +6986,6 @@ v = PyUnicode_New(size, 127); if (v == NULL) goto onError; - if (size == 0) - return v; kind = PyUnicode_KIND(v); data = PyUnicode_DATA(v); outpos = 0; @@ -13856,20 +13854,22 @@ "incomplete format"); goto onError; } - if (c != '%') { - v = getnextarg(args, arglen, &argidx); - if (v == NULL) - goto onError; - } + + if (c == '%') { + _PyAccu_Accumulate(&acc, percent); + continue; + } + + + v = getnextarg(args, arglen, &argidx); + if (v == NULL) + goto onError; + sign = 0; fill = ' '; fillobj = blank; switch (c) { - case '%': - _PyAccu_Accumulate(&acc, percent); - continue; - case 's': case 'r': case 'a': @@ -13884,26 +13884,7 @@ temp = PyObject_Repr(v); else temp = PyObject_ASCII(v); - if (temp == NULL) - goto onError; - if (PyUnicode_Check(temp)) - /* nothing to do */; - else { - Py_DECREF(temp); - PyErr_SetString(PyExc_TypeError, - "%s argument has non-string str()"); - goto onError; - } - } - if (PyUnicode_READY(temp) == -1) { - Py_CLEAR(temp); - goto onError; - } - pbuf = PyUnicode_DATA(temp); - kind = PyUnicode_KIND(temp); - len = PyUnicode_GET_LENGTH(temp); - if (prec >= 0 && len > prec) - len = prec; + } break; case 'i': @@ -13926,18 +13907,9 @@ if (iobj!=NULL) { if (PyLong_Check(iobj)) { isnumok = 1; + sign = 1; temp = formatlong(iobj, flags, prec, (c == 'i'? 'd': c)); Py_DECREF(iobj); - if (!temp) - goto onError; - if (PyUnicode_READY(temp) == -1) { - Py_CLEAR(temp); - goto onError; - } - pbuf = PyUnicode_DATA(temp); - kind = PyUnicode_KIND(temp); - len = PyUnicode_GET_LENGTH(temp); - sign = 1; } else { Py_DECREF(iobj); @@ -13962,21 +13934,12 @@ case 'F': case 'g': case 'G': - temp = formatfloat(v, flags, prec, c); - if (!temp) - goto onError; - if (PyUnicode_READY(temp) == -1) { - Py_CLEAR(temp); - goto onError; - } - pbuf = PyUnicode_DATA(temp); - kind = PyUnicode_KIND(temp); - len = PyUnicode_GET_LENGTH(temp); sign = 1; if (flags & F_ZERO) { fill = '0'; fillobj = zero; } + temp = formatfloat(v, flags, prec, c); break; case 'c': @@ -13985,11 +13948,6 @@ if (ch == (Py_UCS4) -1) goto onError; temp = _PyUnicode_FromUCS4(&ch, 1); - if (temp == NULL) - goto onError; - pbuf = PyUnicode_DATA(temp); - kind = PyUnicode_KIND(temp); - len = PyUnicode_GET_LENGTH(temp); break; } @@ -14002,6 +13960,22 @@ fmtpos - 1); goto onError; } + if (temp == NULL) + goto onError; + assert (PyUnicode_Check(temp)); + if (PyUnicode_READY(temp) == -1) { + Py_CLEAR(temp); + goto onError; + } + kind = PyUnicode_KIND(temp); + pbuf = PyUnicode_DATA(temp); + len = PyUnicode_GET_LENGTH(temp); + + if (c == 's' || c == 'r' || c == 'a') { + if (prec >= 0 && len > prec) + len = prec; + } + /* pbuf is initialized here. */ pindex = 0; if (sign) { -- Repository URL: http://hg.python.org/cpython

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peps: fix link
by benjamin.peterson April 30, 2012

April 30, 2012

http://hg.python.org/peps/rev/c3f2e2c4ebc2 changeset: 4325:c3f2e2c4ebc2 user: Benjamin Peterson <benjamin(a)python.org> date: Sun Apr 29 21:27:35 2012 -0400 summary: fix link files: pep-0415.txt | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/pep-0415.txt b/pep-0415.txt --- a/pep-0415.txt +++ b/pep-0415.txt @@ -70,7 +70,7 @@ ========== .. _issue 14133: - http://bugs.python.org/issue6210 + http://bugs.python.org/issue14133 Copyright ========= -- Repository URL: http://hg.python.org/peps

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cpython: Track the cache size directly.
by raymond.hettinger April 30, 2012

April 30, 2012

http://hg.python.org/cpython/rev/d4fd58fff480 changeset: 76656:d4fd58fff480 user: Raymond Hettinger <python(a)rcn.com> date: Sun Apr 29 18:09:02 2012 -0700 summary: Track the cache size directly. files: Lib/functools.py | 21 +++++++++++---------- 1 files changed, 11 insertions(+), 10 deletions(-) diff --git a/Lib/functools.py b/Lib/functools.py --- a/Lib/functools.py +++ b/Lib/functools.py @@ -168,15 +168,14 @@ # to allow the implementation to change (including a possible C version). # Constants shared by all lru cache instances: - kwd_mark = (object(),) # separate positional and keyword args - sentinel = object() # unique object used to signal cache misses - _len = len # localize the global len() function + kwd_mark = (object(),) # separate positional and keyword args + sentinel = object() # unique object used to signal cache misses PREV, NEXT, KEY, RESULT = 0, 1, 2, 3 # names for the link fields def decorating_function(user_function): cache = {} - hits = misses = 0 + hits = misses = currsize = 0 cache_get = cache.get # bound method to lookup a key or return None lock = Lock() # because linkedlist updates aren't threadsafe root = [] # root of the circular doubly linked list @@ -209,7 +208,7 @@ def wrapper(*args, **kwds): # simple caching without ordering or size limit - nonlocal hits, misses + nonlocal hits, misses, currsize key = make_key(args, kwds, typed) if kwds or typed else args result = cache_get(key, sentinel) if result is not sentinel: @@ -218,13 +217,14 @@ result = user_function(*args, **kwds) cache[key] = result misses += 1 + currsize += 1 return result else: def wrapper(*args, **kwds): # size limited caching that tracks accesses by recency - nonlocal root, hits, misses + nonlocal root, hits, misses, currsize key = make_key(args, kwds, typed) if kwds or typed else args with lock: link = cache_get(key) @@ -241,11 +241,12 @@ return result result = user_function(*args, **kwds) with lock: - if _len(cache) < maxsize: + if currsize < maxsize: # put result in a new link at the front of the queue last = root[PREV] link = [last, root, key, result] cache[key] = last[NEXT] = root[PREV] = link + currsize += 1 else: # use root to store the new key and result root[KEY] = key @@ -261,15 +262,15 @@ def cache_info(): """Report cache statistics""" with lock: - return _CacheInfo(hits, misses, maxsize, len(cache)) + return _CacheInfo(hits, misses, maxsize, currsize) def cache_clear(): """Clear the cache and cache statistics""" - nonlocal hits, misses + nonlocal hits, misses, currsize with lock: cache.clear() root[:] = [root, root, None, None] - hits = misses = 0 + hits = misses = currsize = 0 wrapper.cache_info = cache_info wrapper.cache_clear = cache_clear -- Repository URL: http://hg.python.org/cpython

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cpython: Write the What's New for the importlib stuff.
by brett.cannon April 30, 2012

April 30, 2012

http://hg.python.org/cpython/rev/add8b52db99b changeset: 76655:add8b52db99b user: Brett Cannon <brett(a)python.org> date: Sun Apr 29 20:59:41 2012 -0400 summary: Write the What's New for the importlib stuff. files: Doc/whatsnew/3.3.rst | 122 +++++++++++++++++++++++++++++++ 1 files changed, 122 insertions(+), 0 deletions(-) diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst --- a/Doc/whatsnew/3.3.rst +++ b/Doc/whatsnew/3.3.rst @@ -452,6 +452,89 @@ '<function C.D.meth at 0x7f46b9fe31e0>' +Using importlib as the Implementation of Import +=============================================== +:issue:`2377` - Replace __import__ w/ importlib.__import__ +:issue:`13959` - Re-implement parts of :mod:`imp` in pure Python +:issue:`14605` - Make import machinery explicit +:issue:`14646` - Require loaders set __loader__ and __package__ + +(Written by Brett Cannon) + +The :func:`__import__` function is now powered by :func:`importlib.__import__`. +This work leads to the completion of "phase 2" of :pep:`302`. There are +multiple benefits to this change. First, it has allowed for more of the +machinery powering import to be exposed instead of being implicit and hidden +within the C code. It also provides a single implementation for all Python VMs +supporting Python 3.3 to use, helping to end any VM-specific deviations in +import semantics. And finally it eases the maintenance of import, allowing for +future growth to occur. + +For the common user, this change should result in no visible change in +semantics. Any possible changes required in one's code to handle this change +should read the `Porting Python code`_ section of this document to see what +needs to be changed, but it will only affect those that currently manipulate +import or try calling it programmatically. + +New APIs +-------- +One of the large benefits of this work is the exposure of what goes into +making the import statement work. That means the various importers that were +once implicit are now fully exposed as part of the :mod:`importlib` package. + +In terms of finders, * :class:`importlib.machinery.FileFinder` exposes the +mechanism used to search for source and bytecode files of a module. Previously +this class was an implicit member of :attr:`sys.path_hooks`. + +For loaders, the new abstract base class :class:`importlib.abc.FileLoader` helps +write a loader that uses the file system as the storage mechanism for a module's +code. The loader for source files +(:class:`importlib.machinery.SourceFileLoader`), sourceless bytecode files +(:class:`importlib.machinery.SourcelessFileLoader`), and extension modules +(:class:`importlib.machinery.ExtensionFileLoader`) are now available for +direct use. + +:exc:`ImportError` now has ``name`` and ``path`` attributes which are set when +there is relevant data to provide. The message for failed imports will also +provide the full name of the module now instead of just the tail end of the +module's name. + +The :func:`importlib.invalidate_caches` function will now call the method with +the same name on all finders cached in :attr:`sys.path_importer_cache` to help +clean up any stored state as necessary. + +Visible Changes +--------------- +[For potential required changes to code, see the `Porting Python code`_ +section] + +Beyond the expanse of what :mod:`importlib` now exposes, there are other +visible changes to import. The biggest is that :attr:`sys.meta_path` and +:attr:`sys.path_hooks` now store all of the finders used by import explicitly. +Previously the finders were implicit and hidden within the C code of import +instead of being directly exposed. This means that one can now easily remove or +change the order of the various finders to fit one's needs. + +Another change is that all modules have a ``__loader__`` attribute, storing the +loader used to create the module. :pep:`302` has been updated to make this +attribute mandatory for loaders to implement, so in the future once 3rd-party +loaders have been updated people will be able to rely on the existence of the +attribute. Until such time, though, import is setting the module post-load. + +Loaders are also now expected to set the ``__package__`` attribute from +:pep:`366`. Once again, import itself is already setting this on all loaders +from :mod:`importlib` and import itself is setting the attribute post-load. + +``None`` is now inserted into :attr:`sys.path_importer_cache` when no finder +can be found on :attr:`sys.path_hooks`. Since :class:`imp.NullImporter` is not +directly exposed on :attr:`sys.path_hooks` it could no longer be relied upon to +always be available to use as a value representing no finder found. + +All other changes relate to semantic changes which should be taken into +consideration when updating code for Python 3.3, and thus should be read about +in the `Porting Python code`_ section of this document. + + Other Language Changes ====================== @@ -1283,6 +1366,45 @@ timestamp is out of range. :exc:`OSError` is now raised if C functions :c:func:`gmtime` or :c:func:`localtime` failed. +* The default finders used by import now utilize a cache of what is contained + within a specific directory. If you create a Python source file or sourceless + bytecode file, make sure to call :func:`importlib.invalidate_caches` to clear + out the cache for the finders to notice the new file. + +* :exc:`ImportError` now uses the full name of the module that was attemped to + be imported. Doctests that check ImportErrors' message will need to be + updated to use the full name of the module instead of just the tail of the + name. + +* The **index** argument to :func:`__import__` now defaults to 0 instead of -1 + and no longer support negative values. It was an oversight when :pep:`328` was + implemented that the default value remained -1. If you need to continue to + perform a relative import followed by an absolute import, then perform the + relative import using an index of 1, followed by another import using an + index of 0. It is preferred, though, that you use + :func:`importlib.import_module` rather than call :func:`__import__` directly. + +* :func:`__import__` no longer allows one to use an index value other than 0 + for top-level modules. E.g. ``__import__('sys', level=1)`` is now an error. + +* Because :attr:`sys.meta_path` and :attr:`sys.path_hooks` now have finders on + them by default, you will most likely want to use :meth:`list.insert` instead + of :meth:`list.append` to add to those lists. + +* Because ``None`` is now inserted into :attr:`sys.path_importer_cache`, if you + are clearing out entries in the dictionary of paths that do not have a + finder, you will need to remove keys paired with values of ``None`` **and** + :class:`imp.NullImporter` to be backwards-compatible. This will need to extra + overhead on older versions of Python that re-insert ``None`` into + :attr:`sys.path_importer_cache` where it repesents the use of implicit + finders, but semantically it should not change anything. + +* :meth:`importlib.abc.SourceLoader.path_mtime` is now deprecated in favour of + :meth:`importlib.abc.SourceLoader.path_stats` as bytecode files now store + both the modification time and size of the source file the bytecode file was + compiled from. + + Porting C code -------------- -- Repository URL: http://hg.python.org/cpython

1 0

peps (merge default -> default): merge
by brett.cannon April 30, 2012

April 30, 2012

http://hg.python.org/peps/rev/518e16177cce changeset: 4324:518e16177cce parent: 4323:f1b89efedc7e parent: 4322:a9a6a0851544 user: Brett Cannon <brett(a)python.org> date: Sun Apr 29 20:04:45 2012 -0400 summary: merge files: pep-0008.txt | 16 ++++++++----- pep-0418.txt | 46 ++++++++++++--------------------------- pep-0420.txt | 4 +- 3 files changed, 26 insertions(+), 40 deletions(-) diff --git a/pep-0008.txt b/pep-0008.txt --- a/pep-0008.txt +++ b/pep-0008.txt @@ -841,16 +841,20 @@ whenever they do something other than acquire and release resources. For example: - Yes: with conn.begin_transaction(): + Yes:: + + with conn.begin_transaction(): do_stuff_in_transaction(conn) - No: with conn: + No:: + + with conn: do_stuff_in_transaction(conn) - The latter example doesn't provide any information to indicate that - the __enter__ and __exit__ methods are doing something other than - closing the connection after a transaction. Being explicit is - important in this case. + The latter example doesn't provide any information to indicate that + the __enter__ and __exit__ methods are doing something other than + closing the connection after a transaction. Being explicit is + important in this case. - Use string methods instead of the string module. diff --git a/pep-0418.txt b/pep-0418.txt --- a/pep-0418.txt +++ b/pep-0418.txt @@ -114,20 +114,15 @@ * ``"process_time"``: ``time.process_time()`` * ``"time"``: ``time.time()`` -Return a dictionary with the following keys: +Return a ``time.clock_info`` object which has the following attributes: -* Mandatory keys: - - * ``"implementation"`` (str): name of the underlying operating system - function. Examples: ``"QueryPerformanceCounter()"``, - ``"clock_gettime(CLOCK_REALTIME)"``. - * ``"resolution"`` (float): resolution in seconds of the clock. - * ``"is_monotonic"`` (bool): True if the clock cannot go backward. - -* Optional keys: - - * ``"is_adjusted"`` (bool): True if the clock is adjusted (e.g. by a - NTP daemon). + * ``implementation`` (str): name of the underlying operating system + function. Examples: ``"QueryPerformanceCounter()"``, + ``"clock_gettime(CLOCK_REALTIME)"``. + * ``is_monotonic`` (bool): True if the clock cannot go backward. + * ``is_adjusted`` (bool): True if the clock is adjusted (e.g. by a + NTP daemon). + * ``resolution`` (float): resolution in seconds of the clock. time.monotonic() @@ -610,14 +605,14 @@ :Clock: An instrument for measuring time. Different clocks have different - characteristics; for example, a clock with <nanosecond> + characteristics; for example, a clock with nanosecond <precision> may start to <drift> after a few minutes, while a less precise clock remained accurate for days. This PEP is primarily concerned with clocks which use a unit of seconds. :Counter: A clock which increments each time a certain event occurs. A - counter is <strictly monotonic>, but not <clock_monotonic>. It can + counter is strictly monotonic, but not a monotonic clock. It can be used to generate a unique (and ordered) timestamp, but these timestamps cannot be mapped to <civil time>; tick creation may well be bursty, with several advances in the same millisecond followed @@ -630,12 +625,6 @@ when profiling, but they do not map directly to user response time, nor are they directly comparable to (real time) seconds. -:Duration: - Elapsed time. The difference between the starting and ending - times. A defined <epoch> creates an implicit (and usually large) - duration. More precision can generally be provided for a - relatively small <duration>. - :Drift: The accumulated error against "true" time, as defined externally to the system. Drift may be due to imprecision, or to a difference @@ -657,12 +646,7 @@ Moving in at most one direction; for clocks, that direction is forward. The <clock> should also be <steady>, and should be convertible to a unit of seconds. The tradeoffs often include lack - of a defined <epoch> or mapping to <Civil Time>, and being more - expensive (in <latency>, power usage, or <duration> spent within - calls to the clock itself) to use. For example, the clock may - represent (a constant multiplied by) ticks of a specific quartz - timer on a specific CPU core, and calls would therefore require - synchronization between cores. + of a defined <epoch> or mapping to <Civil Time>. :Precision: The amount of deviation among measurements of the same physical @@ -968,11 +952,9 @@ based on absolute elapsed time since system boot. It is not adjusted and cannot be set. -mach_timebase_info() gives a fraction to convert the clock value to a -number of nanoseconds. According to the documentation (`Technical Q&A -QA1398 <https://developer.apple.com/library/mac/#qa/qa1398/>`_), -mach_timebase_info() is always equal to one and never fails, even if -the function may fail according to its prototype. +mach_timebase_info() gives a fraction to convert the clock value to a number of +nanoseconds. See also the `Technical Q&A QA1398 +<https://developer.apple.com/library/mac/#qa/qa1398/>`_. mach_absolute_time() stops during a sleep on a PowerPC CPU, but not on an Intel CPU: `Different behaviour of mach_absolute_time() on i386/ppc diff --git a/pep-0420.txt b/pep-0420.txt --- a/pep-0420.txt +++ b/pep-0420.txt @@ -122,8 +122,8 @@ * If not, but ``foo`` is found and is a directory, it is recorded. If the scan along the parent path completes without finding a module -or package, then a namespace package is created. The new namespace -package: +or package and at least one directory was recorded, then a namespace +package is created. The new namespace package: * Has a ``__file__`` attribute set to the first directory that was found during the scan, including the trailing path separator. -- Repository URL: http://hg.python.org/peps

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peps: Phase 2 of PEP 302 is done.
by brett.cannon April 30, 2012

April 30, 2012

http://hg.python.org/peps/rev/f1b89efedc7e changeset: 4323:f1b89efedc7e parent: 4316:108e9e328481 user: Brett Cannon <brett(a)python.org> date: Sun Apr 29 20:04:31 2012 -0400 summary: Phase 2 of PEP 302 is done. files: pep-0302.txt | 8 +------- 1 files changed, 1 insertions(+), 7 deletions(-) diff --git a/pep-0302.txt b/pep-0302.txt --- a/pep-0302.txt +++ b/pep-0302.txt @@ -162,13 +162,7 @@ list is yet another new object in the sys.module: sys.meta_path. Currently, this list is empty by default, and frozen and built-in module imports are done after traversing sys.meta_path, but still - before sys.path. (Again, later we can add real frozen, built-in and - sys.path importer objects on sys.meta_path, allowing for some extra - flexibility, but this could be done as a "phase 2" project, possibly - for Python 2.4. It would be the finishing touch as then *every* - import would go through sys.meta_path, making it the central import - dispatcher.) - + before sys.path. Specification part 1: The Importer Protocol -- Repository URL: http://hg.python.org/peps

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cpython: Issue #14428: Remove test_process_time_threads() from test_time
by victor.stinner April 29, 2012

April 29, 2012

http://hg.python.org/cpython/rev/ad3d6010379b changeset: 76654:ad3d6010379b user: Victor Stinner <victor.stinner(a)gmail.com> date: Mon Apr 30 01:39:57 2012 +0200 summary: Issue #14428: Remove test_process_time_threads() from test_time The test is unstable and it's not really interesting to test exactly how threads are handled. files: Lib/test/test_time.py | 52 ------------------------------- 1 files changed, 0 insertions(+), 52 deletions(-) diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py --- a/Lib/test/test_time.py +++ b/Lib/test/test_time.py @@ -389,58 +389,6 @@ self.assertEqual(info.is_monotonic, True) self.assertEqual(info.is_adjusted, False) - @unittest.skipUnless(threading, - 'need threading') - def test_process_time_threads(self): - def factorial(n): - if n >= 2: - return n * factorial(n-1) - else: - return 1 - - def use_cpu(n, loops): - for loop in range(loops): - factorial(n) - - class FactorialThread(threading.Thread): - def __init__(self, n, loops): - threading.Thread.__init__(self) - self.n = n - self.loops = loops - - def run(self): - use_cpu(self.n, self.loops) - - # Calibrate use_cpu() to use at least 1 ms of system time - n = 50 - loops = 1 - resolution = time.get_clock_info('process_time').resolution - min_rdt = max(resolution, 0.001) - while 1: - rt1 = time.time() - t1 = time.process_time() - use_cpu(n, loops) - t2 = time.process_time() - rt2 = time.time() - rdt = rt2 - rt1 - if rdt >= min_rdt: - break - loops *= 2 - busy = t2 - t1 - - # Ensure that time.process_time() includes the CPU time of all threads - thread = FactorialThread(n, loops) - t1 = time.process_time() - thread.start() - # Use sleep() instead of thread.join() because thread.join() time may - # be included in time.process_time() depending on its implementation - time.sleep(rdt * 2) - t2 = time.process_time() - thread.stop = True - thread.join() - # Use a factor of 0.75 because time.process_time() is maybe not precise - self.assertGreaterEqual(t2 - t1, busy * 0.75) - @unittest.skipUnless(hasattr(time, 'monotonic'), 'need time.monotonic') @unittest.skipUnless(hasattr(time, 'clock_settime'), -- Repository URL: http://hg.python.org/cpython

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