Mailman 3 October 2013 - Python-Dev

type.__subclasses__() doesn't work
by Antoine Pitrou 09 Oct '13

09 Oct '13

Hello, Just noticed the following quirk: >>> type.__subclasses__() Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: descriptor '__subclasses__' of 'type' object needs an argument Yet it would be nice to know about the subclasses of type. Regards Antoine.

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On the dangers of giving developers the best resources
by Guido van Rossum 08 Oct '13

08 Oct '13

On Tue, Oct 8, 2013 at 8:33 AM, R. David Murray <rdmurray(a)bitdance.com>wrote: > PS: I have always thought it sad that the ready availability of memory, > CPU speed, and disk space tends to result in lazy programs. I understand > there is an effort/value tradeoff, and I make those tradeoffs myself > all the time...but it still makes me sad. Then, again, in my early > programming days I spent a fair amount of time writing and using Forth, > and that probably colors my worldview. :) > I never used or cared for Forth, but I have the same worldview. I remember getting it from David Rosenthal, an early Sun reviewer. He stated that engineers should be given the smallest desktop computer available, not the largest, so they would feel their users' pain and optimize appropriately. Sadly software vendors who are also hardware vendors have incentives going in the opposite direction -- they want users to feel the pain so they'll buy a new device. -- --Guido van Rossum (python.org/~guido)

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lzma and 'x' mode open
by Tim Heaney 08 Oct '13

08 Oct '13

I love the 'x' mode open in recent versions of Python. I just discovered that lzma.open doesn't support it. It seems there's an elif that explicitly checks the modes allowed. I added "x" and "xb" to the choices and now it seems to work as I would like.

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Re: [Python-Dev] [Python-checkins] cpython (3.3): PythonCAD is now on PyQt, use Wing as a prominent PyGtk example.
by Michael Foord 07 Oct '13

07 Oct '13

On 6 October 2013 11:45, georg.brandl <python-checkins(a)python.org> wrote: > http://hg.python.org/cpython/rev/942b9420e7e9 > changeset: 86065:942b9420e7e9 > branch: 3.3 > parent: 86062:6ced4fb4f711 > user: Georg Brandl <georg(a)python.org> > date: Sun Oct 06 12:46:13 2013 +0200 > summary: > PythonCAD is now on PyQt, use Wing as a prominent PyGtk example. > > Wing is only a good example of PyGtk until Wing 5 is out of beta. They too have switched to PyQt... Michael > Found by Helge Stenström on docs@. > > files: > Doc/library/othergui.rst | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > > diff --git a/Doc/library/othergui.rst b/Doc/library/othergui.rst > --- a/Doc/library/othergui.rst > +++ b/Doc/library/othergui.rst > @@ -20,7 +20,7 @@ > of the library, GTK+ 2. It provides an object oriented interface > that > is slightly higher level than the C one. There are also bindings to > `GNOME <http://www.gnome.org>`_. One well known PyGTK application > is > - `PythonCAD <http://www.pythoncad.org/>`_. An online `tutorial > + `WingIDE <http://wingide.com/>`_. An online `tutorial > <http://www.pygtk.org/pygtk2tutorial/index.html>`_ is available. > > `PyQt <http://www.riverbankcomputing.co.uk/software/pyqt/>`_ > > -- > Repository URL: http://hg.python.org/cpython > > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > https://mail.python.org/mailman/listinfo/python-checkins > > -- http://www.voidspace.org.uk/ May you do good and not evil May you find forgiveness for yourself and forgive others May you share freely, never taking more than you give. -- the sqlite blessing http://www.sqlite.org/different.html

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Fwd: Reduce memory footprint of Python
by Olemis Lang 06 Oct '13

06 Oct '13

forwarding to the list , sorry ... ---------- Forwarded message ---------- From: Olemis Lang <olemis(a)gmail.com> Date: Sun, 6 Oct 2013 17:09:38 -0500 Subject: Re: [Python-Dev] Reduce memory footprint of Python To: Benjamin Peterson <benjamin(a)python.org> On 10/6/13, Benjamin Peterson <benjamin(a)python.org> wrote: > 2013/10/6 Victor Stinner <victor.stinner(a)gmail.com>: >> 2013/10/6 Benjamin Peterson <benjamin(a)python.org>: >>> 2013/10/6 Victor Stinner <victor.stinner(a)gmail.com>: >>>> Hi, >>>> >>>> Slowly, I'm trying to see if it would be possible to reduce the memory >>>> footprint of Python using the tracemalloc module. >>>> >>>> First, I noticed that linecache can allocate more than 2 MB. What do >>>> you think of adding a registry of "clear cache" functions? For >>>> exemple, re.purge() and linecache.clearcache(). gc.collect() clears >>>> free lists. I don't know if gc.collect() should be related to this new >>>> registy (clear all caches) or not. >>> >>> What is the usecase for minimizing the memory usage of Python in the >>> middle of a program? >> >> If you know that your application uses a lot of memory, it is >> interesting to sometimes (when the application is idle) try to release >> some bytes to not use all the system memory. On embedded devices, >> memory is expensive and very limited. Each byte is important :-) > > How many embedded systems are running Python? > <ot> I know of a few of them, and it seems they will be more popular with the growing interest for devices like Raspberry Pi and technologies like 3D printing e.g. http://raspberry-python.blogspot.com/ </ot> -- Regards, Olemis - @olemislc Apache™ Bloodhound contributor http://issues.apache.org/bloodhound http://blood-hound.net Blog ES: http://simelo-es.blogspot.com/ Blog EN: http://simelo-en.blogspot.com/ Featured article: Popularidad de Python, septiembre 2013 - http://goo.gl/fb/tr0XB

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intobject.c free_list and int_dealloc()
by Laurent Luce 06 Oct '13

06 Oct '13

Hello, I am trying to understand how the free list linked-list evolves when an int object is deallocated. At the beginning, free_list is pointing to the last int object (n-1) in the block. We initialize two int objects, free_list now points to the int object: n-3. free_list -> n-3 n-1 -> n-2 n-2 -> n-3 n-3 -> n-4... We delete the first int object initialized: n-1 -> n-3 free_list -> n-1 It seems to me that two elements are now pointing to the n-3 element: n-1 and n-2. I am pretty sure I am missing something here. Can someone let me know? Thanks, Laurent

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Optimization
by Serhiy Storchaka 06 Oct '13

06 Oct '13

Please remember me, what was common decision about CPython-only optimizations which change computation complexity? I.g. constant amortization time of += for byte objects and strings, or linear time of sum() for sequences?

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Wildcard mask and ANY IP
by Amer 06 Oct '13

06 Oct '13

Hello, I would like to thank you for your great effort I have this question: I want to do the following IP address style in python ANY.45.10.ANY ANY.x.y.z I tried something like: 10.45.10.1 0.255.255.0, but it is not accepted I got some errors Any help is appreciated Best regards, Amer

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project culture: take responsibility for your commits
by Stefan Behnel 05 Oct '13

05 Oct '13

Hi, I'm looking back on a rather unpleasant experience that I recently had in this developer community. Actually, twice by now. Here's what I take from it: You should take responsibility for your commits. Sounds like a simple thing - in theory. People make mistakes, that's normal. You can't always know what others do with your code, and so something that might sound like a great idea when you come up with it, may turn out to have a negative impact that you didn't, and sometimes couldn't possibly, anticipate. So, people will come to you and complain. Let's assume these complaints are reasonable (and they certainly aren't always). What do you do in that case? Do you tell them that what's in is in? Do you tell them that you are a core developer and they are not? That they can try to do better, and if they are lucky, find someone else who applies their patch? That's what happened to me recently. Here's what I'd like to see people do instead. 1) You should discuss the issue with them. If their complaints are reasonable, you may simply have been wrong. Or you may have been right, but couldn't know that there was more beyond the visible. Be open. If you're lucky, the discussion will make the problem obvious to someone else, and a patch will come for free. 2) You should invest a reasonable effort to fix the issue yourself. After all, you produced it by changing something, even if you couldn't possibly see it coming. Take responsibility for your commits. 3) If you can't fix your change, consider reverting it. No change is often better than a bad one. Maybe the time wasn't right for it. Maybe there's a better way to do it that isn't obvious yet. Taking a change back is not showing the white feather. It's showing responsibility. I know that these things aren't always easy. Sometimes people come yelling. Sometimes their complaints are plain wrong. Sometimes the huge impact they see is actually minuscule compared to the upsides. And sometimes the real size of the impact may not actually be visible to you. Be open and they will be, too. Stefan

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Summary of Python tracker Issues
by Python tracker 04 Oct '13

04 Oct '13

ACTIVITY SUMMARY (2013-09-27 - 2013-10-04) 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 4256 ( +0) closed 26682 (+58) total 30938 (+58) Open issues with patches: 1960 Issues opened (30) ================== #19066: os.execv fails with spaced names on Windows http://bugs.python.org/issue19066 reopened by techtonik #19111: 2to3 should remove from future_builtins import * http://bugs.python.org/issue19111 opened by maubp #19113: duplicate test names in Lib/ctypes/test/test_functions.py http://bugs.python.org/issue19113 opened by xdegaye #19119: duplicate test name in Lib/test/test_heapq.py http://bugs.python.org/issue19119 opened by xdegaye #19120: shlex.shlex.lineno reports a different number depending on the http://bugs.python.org/issue19120 opened by daniel-s #19121: Documentation guidelines enhancements http://bugs.python.org/issue19121 opened by techtonik #19124: os.execv executes in background on Windows http://bugs.python.org/issue19124 opened by techtonik #19129: 6.2.1. Regular Expression Syntax flags http://bugs.python.org/issue19129 opened by endoalir #19131: Broken support of compressed AIFC files http://bugs.python.org/issue19131 opened by serhiy.storchaka #19133: Transient test failure: test_with_statement (test_ftplib) http://bugs.python.org/issue19133 opened by koobs #19138: doctest.IGNORE_EXCEPTION_DETAIL doesn't match when no detail e http://bugs.python.org/issue19138 opened by jamur2 #19140: inspect.Signature.bind() inaccuracies http://bugs.python.org/issue19140 opened by epsy #19141: Windows Launcher fails to respect PATH http://bugs.python.org/issue19141 opened by gwideman #19142: Cross-compile fails trying to execute foreign pgen on build ho http://bugs.python.org/issue19142 opened by Trevor.Bowen #19143: Finding the Windows version getting messier http://bugs.python.org/issue19143 opened by tim.peters #19145: Inconsistent behaviour in itertools.repeat when using negative http://bugs.python.org/issue19145 opened by vajrasky #19146: Improvements to traceback module http://bugs.python.org/issue19146 opened by gvanrossum #19148: Minor issues with Enum docs http://bugs.python.org/issue19148 opened by Esa.Peuha #19150: IDLE shell fails: "ModifiedInterpreter instance has no attribu http://bugs.python.org/issue19150 opened by Grupobetatesting #19152: ExtensionFileLoader missing get_filename() http://bugs.python.org/issue19152 opened by eric.snow #19153: Embedding into a shared library fails again http://bugs.python.org/issue19153 opened by rinatous #19154: AttributeError: 'NoneType' in http/client.py when using select http://bugs.python.org/issue19154 opened by fviard #19156: Enum helper functions test-coverage http://bugs.python.org/issue19156 opened by CliffM #19157: ipaddress.IPv6Network.hosts function omits network and broadca http://bugs.python.org/issue19157 opened by m01 #19158: BoundedSemaphore.release() subject to races http://bugs.python.org/issue19158 opened by tim.peters #19159: 2to3 incorrectly converts two parameter unicode() constructor http://bugs.python.org/issue19159 opened by gregory.p.smith #19161: collections Counter handles nan strangely http://bugs.python.org/issue19161 opened by Adam.Davison #19164: Update uuid.UUID TypeError exception: integer should not be an http://bugs.python.org/issue19164 opened by makronized #19165: Change formatter warning to DeprecationWarning in 3.5 http://bugs.python.org/issue19165 opened by brett.cannon #19166: Unusued variable in test_keys in Lib/test/test_dict.py http://bugs.python.org/issue19166 opened by vajrasky Most recent 15 issues with no replies (15) ========================================== #19166: Unusued variable in test_keys in Lib/test/test_dict.py http://bugs.python.org/issue19166 #19165: Change formatter warning to DeprecationWarning in 3.5 http://bugs.python.org/issue19165 #19157: ipaddress.IPv6Network.hosts function omits network and broadca http://bugs.python.org/issue19157 #19156: Enum helper functions test-coverage http://bugs.python.org/issue19156 #19154: AttributeError: 'NoneType' in http/client.py when using select http://bugs.python.org/issue19154 #19140: inspect.Signature.bind() inaccuracies http://bugs.python.org/issue19140 #19138: doctest.IGNORE_EXCEPTION_DETAIL doesn't match when no detail e http://bugs.python.org/issue19138 #19133: Transient test failure: test_with_statement (test_ftplib) http://bugs.python.org/issue19133 #19131: Broken support of compressed AIFC files http://bugs.python.org/issue19131 #19129: 6.2.1. Regular Expression Syntax flags http://bugs.python.org/issue19129 #19121: Documentation guidelines enhancements http://bugs.python.org/issue19121 #19113: duplicate test names in Lib/ctypes/test/test_functions.py http://bugs.python.org/issue19113 #19102: Add tests for CLI of the tabnanny module http://bugs.python.org/issue19102 #19100: Use backslashreplace in pprint http://bugs.python.org/issue19100 #19085: Add tkinter basic options tests http://bugs.python.org/issue19085 Most recent 15 issues waiting for review (15) ============================================= #19166: Unusued variable in test_keys in Lib/test/test_dict.py http://bugs.python.org/issue19166 #19157: ipaddress.IPv6Network.hosts function omits network and broadca http://bugs.python.org/issue19157 #19156: Enum helper functions test-coverage http://bugs.python.org/issue19156 #19148: Minor issues with Enum docs http://bugs.python.org/issue19148 #19146: Improvements to traceback module http://bugs.python.org/issue19146 #19145: Inconsistent behaviour in itertools.repeat when using negative http://bugs.python.org/issue19145 #19140: inspect.Signature.bind() inaccuracies http://bugs.python.org/issue19140 #19138: doctest.IGNORE_EXCEPTION_DETAIL doesn't match when no detail e http://bugs.python.org/issue19138 #19131: Broken support of compressed AIFC files http://bugs.python.org/issue19131 #19119: duplicate test name in Lib/test/test_heapq.py http://bugs.python.org/issue19119 #19106: Prepare .hgtouch and Tools/hg/hgtouch.py to run on the bots http://bugs.python.org/issue19106 #19105: pprint doesn't use all width http://bugs.python.org/issue19105 #19104: pprint produces invalid output for long strings http://bugs.python.org/issue19104 #19103: Use pprint in displayhook http://bugs.python.org/issue19103 #19102: Add tests for CLI of the tabnanny module http://bugs.python.org/issue19102 Top 10 most discussed issues (10) ================================= #19087: bytearray front-slicing not optimized http://bugs.python.org/issue19087 29 msgs #19106: Prepare .hgtouch and Tools/hg/hgtouch.py to run on the bots http://bugs.python.org/issue19106 20 msgs #19066: os.execv fails with spaced names on Windows http://bugs.python.org/issue19066 13 msgs #19108: Benchmark runner tries to execute external Python command and http://bugs.python.org/issue19108 13 msgs #19146: Improvements to traceback module http://bugs.python.org/issue19146 11 msgs #19152: ExtensionFileLoader missing get_filename() http://bugs.python.org/issue19152 10 msgs #19099: struct.pack fails first time with unicode fmt http://bugs.python.org/issue19099 9 msgs #16040: nntplib: unlimited readline() from connection http://bugs.python.org/issue16040 8 msgs #19104: pprint produces invalid output for long strings http://bugs.python.org/issue19104 8 msgs #19124: os.execv executes in background on Windows http://bugs.python.org/issue19124 7 msgs Issues closed (55) ================== #4366: cannot find -lpythonX.X when building Python on FreeBSD with - http://bugs.python.org/issue4366 closed by pitrou #12641: Remove -mno-cygwin from distutils http://bugs.python.org/issue12641 closed by pitrou #17326: Windows build docs still referring to VS 2008 in 3.3 http://bugs.python.org/issue17326 closed by berker.peksag #17839: base64 module should use memoryview http://bugs.python.org/issue17839 closed by python-dev #18037: 2to3 passes through string literal which causes SyntaxError in http://bugs.python.org/issue18037 closed by serhiy.storchaka #18129: Fatal Python error: Cannot recover from stack overflow. http://bugs.python.org/issue18129 closed by benjamin.peterson #18594: C accelerator for collections.Counter is slow http://bugs.python.org/issue18594 closed by rhettinger #18596: enable usage of AddressSanitizer in CPython [PATCH] http://bugs.python.org/issue18596 closed by python-dev #18674: Store weak references in modules_by_index http://bugs.python.org/issue18674 closed by pitrou #18690: memoryview not considered a sequence http://bugs.python.org/issue18690 closed by python-dev #18716: Deprecate the formatter module http://bugs.python.org/issue18716 closed by brett.cannon #18857: urlencode of a None value uses the string 'None' http://bugs.python.org/issue18857 closed by orsenthil #18950: Miscellaneous fixes for the sunau module http://bugs.python.org/issue18950 closed by serhiy.storchaka #18990: Remove root attribute from XMLPullParser http://bugs.python.org/issue18990 closed by python-dev #19010: Make XMLPullParser in ElementTree inherit from XMLParser http://bugs.python.org/issue19010 closed by eli.bendersky #19014: Allow memoryview.cast() for empty views http://bugs.python.org/issue19014 closed by pitrou #19040: Problems with overriding Enum.__new__ http://bugs.python.org/issue19040 closed by ethan.furman #19053: read1() from zipfile returns empty data http://bugs.python.org/issue19053 closed by serhiy.storchaka #19069: Built-in float docstrings are not PEP-8 compatible http://bugs.python.org/issue19069 closed by rhettinger #19078: Allow reversed(memoryview), like memoryview http://bugs.python.org/issue19078 closed by python-dev #19086: Make fsum usable incrementally. http://bugs.python.org/issue19086 closed by rhettinger #19089: Windows: Make Ctrl-D exit key combination cross-platform http://bugs.python.org/issue19089 closed by eric.smith #19091: ast.parse gives wrong position for some Names when non-ascii c http://bugs.python.org/issue19091 closed by terry.reedy #19092: ExitStack.__exit__ incorrectly suppresses exceptions in __exit http://bugs.python.org/issue19092 closed by python-dev #19095: Document SSLSocket.getpeercert always returns None without do_ http://bugs.python.org/issue19095 closed by pitrou #19107: CSV output of benchmark runner tries to write to binary file http://bugs.python.org/issue19107 closed by pitrou #19109: 'TestTCPServer' is not defined http://bugs.python.org/issue19109 closed by vinay.sajip #19110: PEP-0 history link is broken http://bugs.python.org/issue19110 closed by georg.brandl #19112: tests of _TestProcess are not run by the multiprocessing test http://bugs.python.org/issue19112 closed by python-dev #19114: duplicate test names in Lib/distutils/tests/test_cmd.py http://bugs.python.org/issue19114 closed by python-dev #19115: duplicate test names in Lib/lib2to3/tests/test_fixers.py http://bugs.python.org/issue19115 closed by python-dev #19116: duplicate test names in Lib/test/test_complex.py http://bugs.python.org/issue19116 closed by python-dev #19117: duplicate test names in Lib/test/test_dis.py http://bugs.python.org/issue19117 closed by python-dev #19118: duplicate test names in Lib/test/test_ftplib.py http://bugs.python.org/issue19118 closed by python-dev #19122: duplicate test name in Lib/test/test_import.py http://bugs.python.org/issue19122 closed by python-dev #19123: duplicate test name in Lib/test/test_regrtest.py http://bugs.python.org/issue19123 closed by python-dev #19125: duplicate test name in Lib/test/test_smtplib.py http://bugs.python.org/issue19125 closed by python-dev #19126: duplicate test name in Lib/test/test_webbrowser.py http://bugs.python.org/issue19126 closed by python-dev #19127: duplicate test name in Lib/xml/dom/minidom.py http://bugs.python.org/issue19127 closed by python-dev #19128: duplicate test name in Mac/Tools/Doc/setup.py http://bugs.python.org/issue19128 closed by ned.deily #19130: PCbuild/readme.txt not up-to-date http://bugs.python.org/issue19130 closed by pitrou #19132: Add compact mode to pprint http://bugs.python.org/issue19132 closed by serhiy.storchaka #19134: test_inspect.py failed if module _multiprocessing not availabl http://bugs.python.org/issue19134 closed by brett.cannon #19135: Spam http://bugs.python.org/issue19135 closed by berker.peksag #19136: CSV, builtin open(), newline arg. Docs broken again. http://bugs.python.org/issue19136 closed by r.david.murray #19137: pprint wrongly formats set and frozenset subclasses http://bugs.python.org/issue19137 closed by serhiy.storchaka #19139: In venv, __VENV_NAME__ is the prompt, not the name http://bugs.python.org/issue19139 closed by python-dev #19144: test_inspect: failure without threads http://bugs.python.org/issue19144 closed by brett.cannon #19147: pydoc3 fcntl.flock documentation gives wrong man page section http://bugs.python.org/issue19147 closed by ned.deily #19149: python bug report http://bugs.python.org/issue19149 closed by ned.deily #19151: Docstring and WindowsRegistryFinder wrong relative to importli http://bugs.python.org/issue19151 closed by eric.snow #19155: Display stack info with color in pdb (the "w" command) http://bugs.python.org/issue19155 closed by ezio.melotti #19160: Inconsistent size for GIL release in hashlib http://bugs.python.org/issue19160 closed by python-dev #19162: datetime.datetime.min.strftime('%Y') not working http://bugs.python.org/issue19162 closed by r.david.murray #19163: PyString_Format with dict http://bugs.python.org/issue19163 closed by python-dev

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Python-Dev October 2013