Mailman 3 May 2011 - Python-Dev

Re: [Python-Dev] [Python-checkins] cpython (3.2): Fix ProcessTestCasePOSIXPurePython to test the module from import when
by Nick Coghlan 29 May '11

29 May '11

On Sun, May 29, 2011 at 2:13 AM, gregory.p.smith <python-checkins(a)python.org> wrote: > Ironically: I don't think any platform should ever actually _use_ the > pure Python subprocess code on POSIX platforms anymore. This at least > tests it properly in this stable branch. The pure python code for > this is likely to be removed in 3.3. Don't do that - keeping the pure Python equivalents around can help reduce the level of effort for other implementations (especially PyPy). Cheers, Nick. -- Nick Coghlan | ncoghlan(a)gmail.com | Brisbane, Australia

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Deprecate codecs.open() and StreamWriter/StreamReader
by Victor Stinner 28 May '11

28 May '11

Hi, In Python 2, codecs.open() is the best way to read and/or write files using Unicode. But in Python 3, open() is preferred with its fast io module. I would like to deprecate codecs.open() because it can be replaced by open() and io.TextIOWrapper. I would like your opinion and that's why I'm writing this email. -- codecs.open() and StreamReader, StreamWriter and StreamReaderWriter classes of the codecs module don't support universal newlines, still have some issues with stateful codecs (like UTF-16/32 BOMs), and each codec has to implement a StreamReader and a StreamWriter class. StreamReader and StreamWriter are stateless codecs (no reset() or setstate() method), and so it's not possible to write a generic fix for all child classes in the codecs module. Each stateful codec has to handle special cases like seek() problems. For example, UTF-16 codec duplicates some IncrementalEncoder/IncrementalDecoder code into its StreamWriter/StreamReader class. The io module is well tested, supports non-seekable streams, handles correctly corner-cases (like UTF-16/32 BOMs) and supports any kind of newlines including an "universal newline" mode. TextIOWrapper reuses incremental encoders and decoders, so BOM issues were fixed only once, in TextIOWrapper. It's trivial to replace a call to codecs.open() by a call to open(), because the two API are very close. The main different is that codecs.open() doesn't support universal newline, so you have to use open(..., newline='') to keep the same behaviour (keep newlines unchanged). This task can be done by 2to3. But I suppose that most people will be happy with the universal newline mode. I don't see which usecase is not covered by TextIOWrapper. But I know some cases which are not supported by StreamReader/StreamWriter. -- I opened an issue for this idea. Brett and Marc-Andree Lemburg don't want to deprecate codecs.open() & friends because they want to be able to write code working on Python 2 and on Python 3 without any change. I don't think it's realistic: nontrivial programs require at least the six module, and most likely the 2to3 program. The six module can have its "codecs.open" function if codecs.open is removed from Python 3.4. StreamReader, StreamWriter, StreamReaderEncoder and EncodedFile are not used in the Python 3 standard library. I tried removed them: except tests of test_codecs which test them directly, the full test suite pass. Read the issue for more information: http://bugs.python.org/issue8796 Victor

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[ANN] Python 2.5.6 released
by "Martin v. Löwis" 27 May '11

27 May '11

On behalf of the Python development team and the Python community, I'm happy to announce the release of Python 2.5.6. There were no changes since the release candidate. This is a source-only release that only includes security fixes. The last full bug-fix release of Python 2.5 was Python 2.5.4. Users are encouraged to upgrade to the latest release of Python 2.7 (which is 2.7.1 at this point). This release is most likely the final release of Python 2.5; under the current release policy, no security issues in Python 2.5 will be fixed after October, 2011. This releases fixes issues with the urllib, urllib2, SimpleHTTPServer, and audiop modules. See the release notes at the website (also available as Misc/NEWS in the source distribution) for details of bugs fixed. For more information on Python 2.5.6, including download links for various platforms, release notes, and known issues, please see: http://www.python.org/2.5.6 Highlights of the previous major Python releases are available from the Python 2.5 page, at http://www.python.org/2.5/highlights.html Enjoy this release, Martin Martin v. Loewis martin(a)v.loewis.de Python Release Manager (on behalf of the entire python-dev team)

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Summary of Python tracker Issues
by Python tracker 27 May '11

27 May '11

ACTIVITY SUMMARY (2011-05-20 - 2011-05-27) Python tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 2813 (+19) closed 21165 (+50) total 23978 (+69) Open issues with patches: 1216 Issues opened (47) ================== #12128: Allow an abc.abstractproperty to be overridden by an instance http://bugs.python.org/issue12128 opened by cool-RR #12129: Document Object Model API - validation http://bugs.python.org/issue12129 opened by Kyle.Keating #12133: ResourceWarning in urllib.request http://bugs.python.org/issue12133 opened by ezio.melotti #12134: json.dump much slower than dumps http://bugs.python.org/issue12134 opened by poq #12135: The spawn function should return stderr. http://bugs.python.org/issue12135 opened by pitrou #12137: EBADF in test_urllibnet http://bugs.python.org/issue12137 opened by pitrou #12139: Add CCC command support to ftplib http://bugs.python.org/issue12139 opened by giampaolo.rodola #12141: sysconfig.get_config_vars('srcdir') fails in specific cases http://bugs.python.org/issue12141 opened by tarek #12142: Reference cycle when importing ctypes http://bugs.python.org/issue12142 opened by poq #12144: cookielib.CookieJar.make_cookies fails for cookies with 'expir http://bugs.python.org/issue12144 opened by Scott.Wimer #12145: distutils2 should support README.rst http://bugs.python.org/issue12145 opened by daniellindsley #12147: smtplib.send_message does not implement corectly rfc 2822 http://bugs.python.org/issue12147 opened by Nicolas.Estibals #12148: Clarify "or-ing together" doctest option flags http://bugs.python.org/issue12148 opened by ekorn #12149: Segfault in _PyObject_GenericGetAttrWithDict http://bugs.python.org/issue12149 opened by ezio.melotti #12151: test_logging fails sometimes http://bugs.python.org/issue12151 opened by haypo #12154: PyDoc Partial Functions http://bugs.python.org/issue12154 opened by JJeffries #12155: queue example doesn't stop worker threads http://bugs.python.org/issue12155 opened by haypo #12156: test_multiprocessing.test_notify_all() timeout (1 hour) on Fre http://bugs.python.org/issue12156 opened by haypo #12157: join method of multiprocessing Pool object hangs if iterable a http://bugs.python.org/issue12157 opened by Gökçen.Eraslan #12160: codecs doc: what is StreamCodec? http://bugs.python.org/issue12160 opened by haypo #12162: Documentation about re \number http://bugs.python.org/issue12162 opened by Seth.Troisi #12163: str.count http://bugs.python.org/issue12163 opened by py.user #12164: str.translate docstring doesn't mention that 'table' can be No http://bugs.python.org/issue12164 opened by mark.dickinson #12165: Nonlocal does not include global; clarify doc http://bugs.python.org/issue12165 opened by Lukas.Petru #12167: test_packaging reference leak http://bugs.python.org/issue12167 opened by pitrou #12168: SysLogHandler incorrectly appends \000 to messages http://bugs.python.org/issue12168 opened by Carl.Crowder #12169: Factor out common code for d2 commands register, upload and up http://bugs.python.org/issue12169 opened by eric.araujo #12170: Bytes.index() and bytes.count() should accept byte ints http://bugs.python.org/issue12170 opened by max-alleged #12171: Reset method of the incremental encoders of CJK codecs calls t http://bugs.python.org/issue12171 opened by haypo #12172: IDLE crashes when I use F5 to run http://bugs.python.org/issue12172 opened by Kevin Ness #12174: Multiprocessing logging levels unclear http://bugs.python.org/issue12174 opened by JJeffries #12175: FileIO.readall() read the file position and size at each read http://bugs.python.org/issue12175 opened by haypo #12177: re.match raises MemoryError http://bugs.python.org/issue12177 opened by EungJun.Yi #12178: csv writer doesn't escape escapechar http://bugs.python.org/issue12178 opened by ebreck #12179: Race condition using PyGILState_Ensure on a new thread http://bugs.python.org/issue12179 opened by syeberman #12181: SIGBUS error on OpenBSD (sparc64) http://bugs.python.org/issue12181 opened by rpointel #12183: Document behaviour of shutil.copy2 and copystat with symlinks http://bugs.python.org/issue12183 opened by mmarkk #12184: socketserver.ForkingMixin collect_children routine needs to co http://bugs.python.org/issue12184 opened by orsenthil #12186: readline.replace_history_item still leaks memory http://bugs.python.org/issue12186 opened by stefanholek #12187: subprocess.wait() with a timeout uses polling on POSIX http://bugs.python.org/issue12187 opened by haypo #12188: PEP 7, C style: add ++ policy and explanation http://bugs.python.org/issue12188 opened by terry.reedy #12190: intern filenames in bytecode http://bugs.python.org/issue12190 opened by Mike.Solomon #12191: Shutil - add chown() in order to allow to use user and group n http://bugs.python.org/issue12191 opened by sandro.tosi #12192: Doc that collection mutation methods return item or None http://bugs.python.org/issue12192 opened by terry.reedy #12195: Little documentation of annotations http://bugs.python.org/issue12195 opened by JJeffries #12196: add pipe2() to the os module http://bugs.python.org/issue12196 opened by charles-francois.natali #12185: Decimal documentation lists "first" and "second" arguments, sh http://bugs.python.org/issue12185 opened by eric.smith Most recent 15 issues with no replies (15) ========================================== #12188: PEP 7, C style: add ++ policy and explanation http://bugs.python.org/issue12188 #12186: readline.replace_history_item still leaks memory http://bugs.python.org/issue12186 #12185: Decimal documentation lists "first" and "second" arguments, sh http://bugs.python.org/issue12185 #12179: Race condition using PyGILState_Ensure on a new thread http://bugs.python.org/issue12179 #12164: str.translate docstring doesn't mention that 'table' can be No http://bugs.python.org/issue12164 #12157: join method of multiprocessing Pool object hangs if iterable a http://bugs.python.org/issue12157 #12156: test_multiprocessing.test_notify_all() timeout (1 hour) on Fre http://bugs.python.org/issue12156 #12142: Reference cycle when importing ctypes http://bugs.python.org/issue12142 #12137: EBADF in test_urllibnet http://bugs.python.org/issue12137 #12129: Document Object Model API - validation http://bugs.python.org/issue12129 #12091: multiprocessing: simplify ApplyResult and MapResult with threa http://bugs.python.org/issue12091 #12066: Empty ('') xmlns attribute is not properly handled by xml.dom. http://bugs.python.org/issue12066 #12053: Add prefetch() for Buffered IO (experiment) http://bugs.python.org/issue12053 #12037: test_email failures under Windows with the eol extension activ http://bugs.python.org/issue12037 #11992: sys.settrace doesn't disable tracing if a local trace function http://bugs.python.org/issue11992 Most recent 15 issues waiting for review (15) ============================================= #12196: add pipe2() to the os module http://bugs.python.org/issue12196 #12191: Shutil - add chown() in order to allow to use user and group n http://bugs.python.org/issue12191 #12190: intern filenames in bytecode http://bugs.python.org/issue12190 #12184: socketserver.ForkingMixin collect_children routine needs to co http://bugs.python.org/issue12184 #12175: FileIO.readall() read the file position and size at each read http://bugs.python.org/issue12175 #12174: Multiprocessing logging levels unclear http://bugs.python.org/issue12174 #12171: Reset method of the incremental encoders of CJK codecs calls t http://bugs.python.org/issue12171 #12165: Nonlocal does not include global; clarify doc http://bugs.python.org/issue12165 #12164: str.translate docstring doesn't mention that 'table' can be No http://bugs.python.org/issue12164 #12160: codecs doc: what is StreamCodec? http://bugs.python.org/issue12160 #12154: PyDoc Partial Functions http://bugs.python.org/issue12154 #12149: Segfault in _PyObject_GenericGetAttrWithDict http://bugs.python.org/issue12149 #12147: smtplib.send_message does not implement corectly rfc 2822 http://bugs.python.org/issue12147 #12144: cookielib.CookieJar.make_cookies fails for cookies with 'expir http://bugs.python.org/issue12144 #12139: Add CCC command support to ftplib http://bugs.python.org/issue12139 Top 10 most discussed issues (10) ================================= #8898: The email package should defer to the codecs module for all al http://bugs.python.org/issue8898 30 msgs #12006: strptime should implement %V or %u directive from libc http://bugs.python.org/issue12006 23 msgs #5715: listen socket close in SocketServer.ForkingMixIn.process_reque http://bugs.python.org/issue5715 18 msgs #12175: FileIO.readall() read the file position and size at each read http://bugs.python.org/issue12175 16 msgs #12181: SIGBUS error on OpenBSD (sparc64) http://bugs.python.org/issue12181 14 msgs #12085: subprocess.Popen.__del__ raises AttributeError if __init__ was http://bugs.python.org/issue12085 11 msgs #12168: SysLogHandler incorrectly appends \000 to messages http://bugs.python.org/issue12168 10 msgs #12042: What's New multiprocessing example error http://bugs.python.org/issue12042 9 msgs #12057: HZ codec has no test http://bugs.python.org/issue12057 9 msgs #12167: test_packaging reference leak http://bugs.python.org/issue12167 9 msgs Issues closed (44) ================== #1625: bz2.BZ2File doesn't support multiple streams http://bugs.python.org/issue1625 closed by nadeem.vawda #9435: test_distutils fails without zlib http://bugs.python.org/issue9435 closed by eric.araujo #9942: Allow memory sections to be OS MERGEABLE http://bugs.python.org/issue9942 closed by loewis #10818: pydoc: Remove old server and tk panel http://bugs.python.org/issue10818 closed by haypo #10832: Add support of bytes objects in PyBytes_FromFormatV() http://bugs.python.org/issue10832 closed by haypo #11998: test_signal cannot test blocked signals if _tkinter is loaded; http://bugs.python.org/issue11998 closed by haypo #12003: documentation: alternate version of xrange seems to fail. http://bugs.python.org/issue12003 closed by eli.bendersky #12024: 2.6 svn and hg branches are out of sync http://bugs.python.org/issue12024 closed by barry #12045: external shell command executed twice in ctypes.util._get_sona http://bugs.python.org/issue12045 closed by pitrou #12049: expose RAND_bytes() function of OpenSSL http://bugs.python.org/issue12049 closed by haypo #12070: Unlimited loop in sysconfig._parse_makefile() http://bugs.python.org/issue12070 closed by haypo #12071: test_concurrent_futures.test_context_manager_shutdown() hangs http://bugs.python.org/issue12071 closed by haypo #12074: regrtest: display the current number of failures http://bugs.python.org/issue12074 closed by haypo #12079: decimal.py: TypeError precedence in fma() http://bugs.python.org/issue12079 closed by mark.dickinson #12100: Incremental encoders of CJK codecs reset the codec at each cal http://bugs.python.org/issue12100 closed by haypo #12105: open() does not able to set flags, such as O_CLOEXEC http://bugs.python.org/issue12105 closed by charles-francois.natali #12113: test_packaging fails when run twice http://bugs.python.org/issue12113 closed by haypo #12114: packaging.util._find_exe_version(): potential deadlock http://bugs.python.org/issue12114 closed by python-dev #12121: test_packaging failure when ssl is not available http://bugs.python.org/issue12121 closed by haypo #12124: python -m test test_packaging test_zipimport failure http://bugs.python.org/issue12124 closed by haypo #12126: incorrect select documentation http://bugs.python.org/issue12126 closed by eli.bendersky #12130: regex 0.1.20110514 findall overlapped not working with 'start http://bugs.python.org/issue12130 closed by brian.curtin #12131: python built with --prefix fails in site.py with no section 'p http://bugs.python.org/issue12131 closed by ned.deily #12132: test_packaging failures when run with -j http://bugs.python.org/issue12132 closed by tarek #12136: test_logging fails when no ssl available http://bugs.python.org/issue12136 closed by vinay.sajip #12138: buggy use of transient_internet() in test_urllibnet http://bugs.python.org/issue12138 closed by pitrou #12140: Crash upon start up http://bugs.python.org/issue12140 closed by amaury.forgeotdarc #12143: packaging extension gcc linking fails on Ubuntu Shared http://bugs.python.org/issue12143 closed by eric.araujo #12146: Possible bug in 're' documentation example http://bugs.python.org/issue12146 closed by eli.bendersky #12150: test_sysconfig fails on solaris http://bugs.python.org/issue12150 closed by haypo #12152: Parser/asdl_c.py relies on mercurial repository revision http://bugs.python.org/issue12152 closed by doko #12153: Modules/faulthandler.c exports `stack_overflow' symbol http://bugs.python.org/issue12153 closed by python-dev #12158: platform: add linux_version() http://bugs.python.org/issue12158 closed by lemburg #12159: Integer Overflow in __len__ http://bugs.python.org/issue12159 closed by benjamin.peterson #12161: StringIO AttributeError instead of ValueError after close.. http://bugs.python.org/issue12161 closed by python-dev #12166: object.__dir__ http://bugs.python.org/issue12166 closed by python-dev #12173: PyImport_ImportModuleLevel doesn't have 'const' on its argumen http://bugs.python.org/issue12173 closed by python-dev #12176: Compiling Python 2.7.1 on Ubuntu 11.04 (Natty Narwhale) http://bugs.python.org/issue12176 closed by skrah #12180: test_packaging: failures --without-threads http://bugs.python.org/issue12180 closed by tarek #12182: pydoc.py integer division problem http://bugs.python.org/issue12182 closed by python-dev #12189: Python 2.6.6 fails to compile a source whereas pycompile 1.0 a http://bugs.python.org/issue12189 closed by r.david.murray #12193: Argparse does not work together with gettext and non-ASCII hel http://bugs.python.org/issue12193 closed by thorsten #12194: Fix LDFLAGS on Ubuntu 11.04+ http://bugs.python.org/issue12194 closed by barry #1441530: socket read() can cause MemoryError in Windows http://bugs.python.org/issue1441530 closed by charles-francois.natali

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Re: [Python-Dev] [Python-checkins] cpython: Avoid useless "++" at the end of functions
by Eric Smith 27 May '11

27 May '11

So, given the discussions about this change, can you please revert it, Victor? Eric. On 05/26/2011 08:07 AM, victor.stinner wrote: > http://hg.python.org/cpython/rev/7ba176c2f558 > changeset: 70397:7ba176c2f558 > user: Victor Stinner <victor.stinner(a)haypocalc.com> > date: Thu May 26 13:53:47 2011 +0200 > summary: > Avoid useless "++" at the end of functions > > Warnings found by the Clang Static Analyzer. > > files: > Objects/setobject.c | 4 ++-- > Objects/unicodeobject.c | 2 +- > Python/compile.c | 6 +++--- > 3 files changed, 6 insertions(+), 6 deletions(-) > > > diff --git a/Objects/setobject.c b/Objects/setobject.c > --- a/Objects/setobject.c > +++ b/Objects/setobject.c > @@ -612,9 +612,9 @@ > *u++ = '{'; > /* Omit the brackets from the listrepr */ > Py_UNICODE_COPY(u, PyUnicode_AS_UNICODE(listrepr)+1, > - PyUnicode_GET_SIZE(listrepr)-2); > + newsize-2); > u += newsize-2; > - *u++ = '}'; > + *u = '}'; > } > Py_DECREF(listrepr); > if (Py_TYPE(so) != &PySet_Type) { > diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c > --- a/Objects/unicodeobject.c > +++ b/Objects/unicodeobject.c > @@ -6474,7 +6474,7 @@ > } > } > /* 0-terminate the output string */ > - *output++ = '\0'; > + *output = '\0'; > Py_XDECREF(exc); > Py_XDECREF(errorHandler); > return 0; > diff --git a/Python/compile.c b/Python/compile.c > --- a/Python/compile.c > +++ b/Python/compile.c > @@ -3747,11 +3747,11 @@ > a->a_lnotab_off += 2; > if (d_bytecode) { > *lnotab++ = d_bytecode; > - *lnotab++ = d_lineno; > + *lnotab = d_lineno; > } > else { /* First line of a block; def stmt, etc. */ > *lnotab++ = 0; > - *lnotab++ = d_lineno; > + *lnotab = d_lineno; > } > a->a_lineno = i->i_lineno; > a->a_lineno_off = a->a_offset; > @@ -3796,7 +3796,7 @@ > if (i->i_hasarg) { > assert(size == 3 || size == 6); > *code++ = arg & 0xff; > - *code++ = arg >> 8; > + *code = arg >> 8; > } > return 1; > } > > > > > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > http://mail.python.org/mailman/listinfo/python-checkins

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Re: [Python-Dev] [Python-checkins] cpython: Avoid useless "++" at the end of functions
by Victor Stinner 26 May '11

26 May '11

Le jeudi 26 mai 2011 à 08:13 -0400, Eric Smith a écrit : > If you're ever going to add code at the end of these functions, it's > unlikely you'll remember that you need to add these increments back in. You don't have to remember. Test the result of the function, it will not give the expected output. I don't think that you need fuzzing or a complex tool to detect that the new code doesn't behave correctly. > It's a bug waiting to happen What? It's not a bug. Ading new non-tested code is a bug :-) > I don't see any harm leaving them in. > Maybe we should add a comment about why they're done. It makes Python faster (!) and make silent the Clang Static Analyzer :-) Victor

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Re: [Python-Dev] cpython: Fix closes issue #11109 - socketserver.ForkingMixIn leaves zombies, also fails
by Antoine Pitrou 26 May '11

26 May '11

On Wed, 25 May 2011 18:26:46 +0200 senthil.kumaran <python-checkins(a)python.org> wrote: > > A new method called service_action is made available in BaseServer, called by > serve_forever loop. This useful in cases where Mixins can use it for cleanup > action. ForkingMixin class uses service_action to collect the zombie child > processes. Initial Patch by Justin Wark. Is it reasonable, performance-wise, to do this at every iteration of the loop (that is, at every incoming connection)? Regards Antoine.

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multibytecodex
by Laura Creighton 25 May '11

25 May '11

This just in from pypy-dev. I am reposting it here because I am fairly certain that nobody on the pypy-dev mailing list uses the multibytecodex, but there has got to be at least one person here who does. Please reply to the pypy-dev article, not here, or mail to pypy-dev(a)python.org if you are not on the pypy-dev mailing list (but have delivery turned off as many of you do.) Thank you, Laura ------- Forwarded Message From: Armin Rigo <arigo(a)tunes.org> Date: Wed, 25 May 2011 21:39:35 +0200 To: pypy-dev(a)python.org Subject: [pypy-dev] multibytecodec: missing features Hi all, Here are the missing features in multibytecodec: * support for ``errors !=3D "strict"''. * classes MultibyteIncrementalEncoder, MultibyteIncrementalDecoder, MultibyteStreamReader and MultibyteStreamWriter. One reason I didn't implement the classes yet is that I couldn't understand two points in how they are supposed to work. But it seems that there are really two bugs, as I've been pointed to: http://bugs.python.org/issue12100 and http://bugs.python.org/issue12171 . So the question is if we should be bug-compatible with Python 2.7 or if we should instead implement some fixed version. I suppose I'm rather for the fixed version, but I'd like to hear some feedback from people that actually use multibytecodecs. Also, I wouldn't mind if someone would pick up the work and just do it, either the classes or ``errors !=3D "strict"'' :-) A bient=F4t, Armin. _______________________________________________ pypy-dev mailing list pypy-dev(a)python.org http://mail.python.org/mailman/listinfo/pypy-dev ------- End of Forwarded Message

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Python 3.3 release schedule posted
by Georg Brandl 25 May '11

25 May '11

I've posted a very preliminary Python 3.3 release schedule as PEP 398. The final release is set to be about 18 months after 3.2 final, which is in August 2012. For 3.3, I'd like to revive the tradition of listing planned large-scale changes in the PEP. Please let me know if you plan any such changes, at any time. (If they aren't codified in PEP form, we should think about whether they should be.) The "Candidate PEPs" I listed are those open PEPs that in my opinion have the highest chance to be accepted and implemented for 3.3. It is by no means binding. cheers, Georg

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Re: [Python-Dev] [Python-checkins] cpython: Issue #12049: Add RAND_bytes() and RAND_pseudo_bytes() functions to the ssl
by Victor Stinner 25 May '11

25 May '11

Le mardi 24 mai 2011 à 11:27 -0400, Terry Reedy a écrit : > > > > +.. function:: RAND_bytes(num) > > + > > + Returns *num* cryptographically strong pseudo-random bytes. > > + > > + .. versionadded:: 3.3 > > + > > +.. function:: RAND_pseudo_bytes(num) > > + > > + Returns (bytes, is_cryptographic): bytes are *num* pseudo-random bytes, > > + is_cryptographic is True if the bytes generated are cryptographically > > + strong. > > + > > + .. versionadded:: 3.3 > > I am curious what 'cryptographically strong' means, what the real > difference is between the above two functions, and how these do not > duplicate what is in random.random. An important feature of a CPRNG (cryptographic pseudo-random number generator) is that even if you know all of its output, you cannot rebuild its internal state to guess next (or maybe previous number). The CPRNG can for example hash its output using SHA-1: you will have to "break" the SHA-1 hash (maybe using "salt"). Another important feature is that even if you know the internal state, you will not be able to guess all previous and next numbers, because the internal state is regulary updated using an external source of entropy. Use RAND_add() to do that explicitly. We may add a link to Wikipedia: http://en.wikipedia.org/wiki/CPRNG Read the "Requirements" section, it's maybe more correct than my explanation: http://en.wikipedia.org/wiki/CPRNG#Requirements About the random module, it must not be used to generate passwords or certificates, because it is easy to rebuild the internal state of a Mersenne Twister generator if you know the previous 624 numbers. Since you know the state, it's also easy to generate all next numbers. Seed a Mersenne Twister PRNG doesn't help. See my Hasard project if you would like to learn more about PRNG ;-) We may also add a link from random to SSL.RAND_bytes() and SSL.RAND_pseudo_bytes(). https://bitbucket.org/haypo/hasard/ Victor

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