Mailman 3 June 2005 - Python-Dev

python running in several threads
by Martin Aliger June 15, 2005

June 15, 2005

Hello Python developers, I know this is developers list and I hope I'm right here. I'm using python as scripting engine embedded in application but issue should be more general. When several scripts are executed simultaneously (under several threads) one have to acquire/release locks. This degrades performance IMHO, mainly on server installations (many web servers use python engine). Moreover those scripts are commonly independent chunks of code which do not create other threats. Under those limitations, do you think, an easy rewrite of execution engine is possible to allow simultaneous run of all threads? I checked the sources esp. PyThreadState object and it seems all those variables could be held locally. Another way is using thread local storage, but it could be a little problematic with porting issues. How do you see it? Do you have any plans here? Thanks and regards, Martin

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Re: [Python-Dev] Wishlist: dowhile
by Andrew Koenig June 15, 2005

June 15, 2005

> > I believe that Algol 68 loops looked like the following (in somewhat > > more Python-like terms): > > > > [for <identifier> [from <suite>] [step <suite>] to <suite>] > > [while <suite>] > > do <suite> od > As far as I remember, it was: > do > <suite> > while <suite; ending with a boolean value> > <suite> > od > It might be that this could be preceded by a 'for' clause, but memory > fails me there. To be completely sure, I dug out my copy of the "Informal Introduction to Algol 68" by Lindsey and van der Meulen. This book is the official Algol 68 tutorial book. It describes the "loop clause" as follows: for some int identifier, which is hereby declared from some meek int unit by some other meek int unit to a third meek int unit while a meek bool enquiry-clause do a void serial-clause od where any of these keywords and its sequel can be omitted, except for "do" or "od". Here, the term "meek" refers to how aggressively the compiler should try to convert the result to int; it specifies, for example, that if after "from" you write the name of a procedure without arguments, that procedure will be called instead of using the procedure itself as a starting point (which would be nonsensical).

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Compiling Python with Intel compiler?
by Guido van Rossum June 15, 2005

June 15, 2005

Intel has a free (as in beer) C compiler for Linux. A friend of mine is involved in its production and marketing. He would like to see how "his" compiler does on Python -- does it work at all, and is there a speedup? I promised him I'd look into this, but between PEPs and my day job I don't seem to have the time, so now I'm making up on my promise by trying to delegate... The compiler is here: http://www.intel.com/software/products/compilers/clin/index.htm On the right is a link to a "Free Non-Commercial Download". That's all I know. I think that if someone puts some time in this, they should get a free Intel T-shirt. -- --Guido van Rossum (home page: http://www.python.org/~guido/)

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Weekly Python Patch/Bug Summary
by Kurt B. Kaiser June 15, 2005

June 15, 2005

Patch / Bug Summary ___________________ Patches : 338 open ( -1) / 2861 closed ( +4) / 3199 total ( +3) Bugs : 909 open ( +1) / 5047 closed (+11) / 5956 total (+12) RFE : 188 open ( -1) / 170 closed ( +2) / 358 total ( +1) New / Reopened Patches ______________________ byteorder issue in PyMac_GetOSType (2005-06-10) http://python.org/sf/1218421 opened by Ronald Oussoren os.kill on windows (2005-06-14) http://python.org/sf/1220212 opened by Miki Tebeka _csv.c leaks when dialect creation fails (2005-06-14) http://python.org/sf/1220242 opened by Michael Hudson Patches Closed ______________ in IDLE, assume new text files are python source by default (2005-05-06) http://python.org/sf/1196895 closed by kbk Add const specifier to PySpam_System prototype (2005-04-21) http://python.org/sf/1187396 closed by birkenfeld Newline in error output of py_compile.compile (2005-03-26) http://python.org/sf/1171150 closed by birkenfeld trivial bug in error message text (2005-05-06) http://python.org/sf/1196980 closed by kbk New / Reopened Bugs ___________________ email.Utils.py: "'" in RFC2231 header (2005-06-10) http://python.org/sf/1218081 opened by Tokio Kikuchi inspect.getsource doesn't update when a module is reloaded (2005-06-10) http://python.org/sf/1218234 opened by Björn Lindqvist Parser chokes on big files (2005-06-11) CLOSED http://python.org/sf/1218930 opened by Alexander Schremmer 'Expression' AST Node not documented (2005-06-12) http://python.org/sf/1219273 opened by Martin Miller copy.py typo (2005-06-13) CLOSED http://python.org/sf/1219342 opened by Ori Avtalion copy.py typo (2005-06-13) CLOSED http://python.org/sf/1219361 opened by Ori Avtalion small output bug (2005-06-12) CLOSED http://python.org/sf/1219448 opened by Alex Levchuk Need locale arg to strftime() (2005-06-13) http://python.org/sf/1219840 opened by Wilfredo Sanchez misdocumented argument range for curses.pair_content (2005-06-13) CLOSED http://python.org/sf/1219862 opened by dcrosta tp_richcompare documentation wrong and incomplete (2005-06-13) http://python.org/sf/1219903 opened by Barry A. Warsaw subprocess call() helper should close stdin if PIPE (2005-06-14) http://python.org/sf/1220113 opened by Stuart Bishop Re-importing embedded thread dumps core (2005-06-14) http://python.org/sf/1220756 opened by Jay T Miller Bugs Closed ___________ Parser chokes on big files (2005-06-11) http://python.org/sf/1218930 closed by doerwalter color highlighting not working on EDIT windows (2003-09-04) http://python.org/sf/800432 closed by kbk No syntax hilite on new file until saved as *.py (2003-07-21) http://python.org/sf/775012 closed by kbk copy.py typo (2005-06-12) http://python.org/sf/1219342 closed by rhettinger copy.py typo (2005-06-12) http://python.org/sf/1219361 closed by rhettinger small output bug (2005-06-12) http://python.org/sf/1219448 closed by rhettinger misdocumented argument range for curses.pair_content (2005-06-13) http://python.org/sf/1219862 closed by akuchling lax error-checking in new-in-2.4 marshal stuff (2005-04-11) http://python.org/sf/1180997 closed by mwh String and list methods documentation deeply hidden (2005-06-06) http://python.org/sf/1215887 closed by rhettinger Queue.qsize() better info about unreliability (2005-06-02) http://python.org/sf/1213475 closed by rhettinger weakref cannot handle bound methods (in contrast to docu) (2005-05-22) http://python.org/sf/1206537 closed by rhettinger New / Reopened RFE __________________ Create a fat build on darwin (2005-06-10) http://python.org/sf/1218333 opened by Ronald Oussoren RFE Closed __________ Make bisect.* functions accept an optional compare function (2005-04-18) http://python.org/sf/1185383 closed by rhettinger sets needs an 'arbitrary element' method (2005-05-31) http://python.org/sf/1212091 closed by rhettinger

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Dynamic class inheritance && something else
by Vero June 14, 2005

June 14, 2005

Hi. My name is Veronica, I am a master student at UNAM. I am working on something related to Artificial Inteligence and I have been looking for the most appropriated programming language to implement my algorithms. I found python to be very close to what I need, but there are still a couple of details that I haven't been able to solve. First, (and most important) I would like to be able to dynamically modify the classes from which a class inherits. I haven't found any way to do it with the language as it is. If there is a way, any suggestion will be truly appreciated. If I had to modify the source code to achieve this, I hope that you could give me some hints; I have an idea of how something like this could be achieved but since I don't know deeply the python sourcode I could get lost. Second, since my program will be modifying classes during run time, I would like to have a way to write on a file the python code that would have defined the class with the functions and attributes as they were left, just as if it had been writen like that at the very begining. I need it to be python code because I will be using that latter. Maybe I will have to solve this second problem by myself but I just wrote in case anybody had a good idea. Thank you very much for your help. Vero La sociedad es inherentemente democrática: la mayoría decide si pensar por si misma o si dejar que alguien más les diga qué pensar. http://mx.geocities.com/aqua_azul_2000/ --------------------------------- Do You Yahoo!? La mejor conexión a Internet y 2GB extra a tu correo por $100 al mes. http://net.yahoo.com.mx

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A bug in pyconfig.h under Linux?
by Fernando Perez June 14, 2005

June 14, 2005

Hi all, sorry for posting to this list, but I'm not even 100% sure this is a bug. If it is, I'll gladly post it to SF if you folks want it there. I use scipy a lot, and the weave.inline component in there allows dynamic inclusion of C/C++ code in Python sources. In particular, it supports Blitz++ array expressions for access to Numeric arrays. However, whenever I use blitz-based code, I get these annoying warnings: ================================================================================ In file included from /usr/include/python2.3/Python.h:8, from sc_weave.cpp:5: /usr/include/python2.3/pyconfig.h:850:1: warning: "_POSIX_C_SOURCE" redefined In file included from /usr/lib/gcc/i386-redhat-linux/3.4.3/../../../../include/c++/3.4.3/i386-redhat-linux/bits/os_defines.h:39, from /usr/lib/gcc/i386-redhat-linux/3.4.3/../../../../include/c++/3.4.3/i386-redhat-linux/bits/c++config.h:35, from /usr/lib/gcc/i386-redhat-linux/3.4.3/../../../../include/c++/3.4.3/string:45, from /usr/lib/python2.3/site-packages/weave/blitz-20001213/blitz/blitz.h:153, from /usr/lib/python2.3/site-packages/weave/blitz-20001213/blitz/array-impl.h:154, from /usr/lib/python2.3/site-packages/weave/blitz-20001213/blitz/array.h:94, from sc_weave.cpp:4: /usr/include/features.h:150:1: warning: this is the location of the previous definition ================================================================================ This is on a Fedora Core 3 box, using glibc-headers.i386 version 2.3.5. The source of the problem seems to be that in file /usr/include/python2.3/pyconfig.h, line 850, I have: /* Define to activate features from IEEE Stds 1003.1-2001 */ #define _POSIX_C_SOURCE 200112L But the system headers, in /usr/include/features.h, line 150 give: # define _POSIX_C_SOURCE 199506L Hence the double-define. Now, I noticed that the system headers all use the following approach to defining these constants: # undef _POSIX_SOURCE # define _POSIX_SOURCE 1 # undef _POSIX_C_SOURCE # define _POSIX_C_SOURCE 199506L etc. That is, they undef everything before defining their value. I applied the same change manually to pyconfig.h: /* Define to activate features from IEEE Stds 1003.1-2001 */ #undef _POSIX_C_SOURCE #define _POSIX_C_SOURCE 200112L and my spurious warnings went away. But I realize that pyconfig.h is auto-generated, so the right solution, if this is indeed a bug, has to be applied somewhere else, at the code generation source. I am unfortunately not familiar enough with Python's build system and the autoconf toolset to do that. Furthermore, I am not even 100% sure this is really a bug, though the spurious warning is very annoying. If this is indeed a bug, do you folks want it reported on SF as such? In that case, is this explanation enough/correct? Any advice would be much appreciated. Regards, Fernando.

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Re: [Python-Dev] Wishlist: dowhile
by Michael Chermside June 14, 2005

June 14, 2005

Jp Calderone writes: > Anything can be a for loop. > > for chunk in iter(lambda: f1.read(CHUNK_SIZE), ''): > f2.write(chunk) Raymond responds: > It would be nice to have this encapsulated in a file method: > > for chunk in f1.iterblocks(CHUNK_SIZE): > f2.write(chunk) What ever happened to "Not every 3 line function needs to be a builtin"? It's a common pattern. It's easy to do. Where's the problem? -- Michael Chermside

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Re: [Python-Dev] PEP 342 - Enhanced Iterators
by "정출연" June 14, 2005

June 14, 2005

<-----Original Message-----> > From: "Guido van Rossum" <gvanrossum(a)gmail.com> > To: "Delaney, Timothy C (Timothy)" <tdelaney(a)avaya.com> > Cc: <python-dev(a)python.org> > Sent: 2005-06-14 10:31 > Subject: Re: [Python-Dev] PEP 342 - Enhanced Iterators Good idea, done. On 6/13/05, Delaney, Timothy C (Timothy) <tdelaney(a)avaya.com> wrote: > There's a thread on c.l.py at the moment ("Controlling a generator the > pythonic way") which is basically coming up with PEP 342. I've pointed > them to PEP 342, but it's made me think that the name of the PEP could > better indicate what it does. > > I propose "Coroutines via Enhanced Iterators". > > Tim Delaney > _______________________________________________ > Python-Dev mailing list > Python-Dev(a)python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: http://mail.python.org/mailman/options/python-dev/guido%40python.org > -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-Dev mailing list Python-Dev(a)python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/iextream%40naver.com ------------------------------------------------------------------------ 네이버 :: 똑! 소리나게 바뀐 네이버 메일을 만나보세요. http://mail.naver.com/

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PEP 342 - Enhanced Iterators
by Delaney, Timothy C (Timothy) June 14, 2005

June 14, 2005

There's a thread on c.l.py at the moment ("Controlling a generator the pythonic way") which is basically coming up with PEP 342. I've pointed them to PEP 342, but it's made me think that the name of the PEP could better indicate what it does. I propose "Coroutines via Enhanced Iterators". Tim Delaney

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AIX 4.3, Python 2.4.1 fails in test_exceptions with a core dump
by Michael Kent June 13, 2005

June 13, 2005

I'm attempting to switch from 2.3.2 to 2.4.1 on our AIX 4.3 development system. I have no problems building Python 2.3.2. I build Python 2.4.1 using 'configure --without-threads; gmake; gmake test', and always get a coredump during the tests on 'test_exceptions'. I've searched for any reports of this problem on the Sourceforge bug list and here, with no success. Has anyone seen this problem?

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