Mailman 3 February 2000 - Python-Dev

Re: Python-checkins digest, Vol 1 #370 - 8 msgs
by M.-A. Lemburg March 5, 2000

March 5, 2000

> Message: 7 > Date: Thu, 24 Feb 2000 10:23:05 -0500 (EST) > From: Guido van Rossum <guido(a)cnri.reston.va.us> > To: python-checkins(a)python.org > Subject: [Python-checkins] CVS: python/dist/src/Objects listobject.c,2.63,2.64 > > Update of /projects/cvsroot/python/dist/src/Objects > In directory eric:/projects/python/develop/guido/src/Objects > > Modified Files: > listobject.c > Log Message: > Made all list methods use PyArg_ParseTuple(),… [View More]

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Unicode mapping tables
by M.-A. Lemburg March 5, 2000

March 5, 2000

I am just coding the translate method for Unicode objects and have come along a design question that may have some importance with resp. to speed and memory allocation size. Currently, mapping tables map characters to Unicode characters and vice-versa. Now the .translate method will use a different kind of table: mapping integer ordinals to integer ordinals. Question: What is more of efficient: having lots of integers in a dictionary or lots of characters ? Another aspect of this question is:… [View More]

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Re: Python / Haskell (fwd)
by gvwilson＠nevex.com Feb. 29, 2000

Feb. 29, 2000

[Forwarded to this list with Phil Wadler's permission.] > Greg Wilson wrote: > Hi, Phil. I was talking to a couple of colleagues over the weekend, > one of whom learned Miranda as his second language and never really > recovered :-). I was wondering: if you could add one or two features > of Haskell to Python, what would you choose? And why? Philip Wadler <wadler(a)research.bell-labs.com> wrote: Well, what I most want is typing. But you already know that. Next after … [View More]

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tracking memory consumption
by pf＠artcom-gmbh.de Feb. 29, 2000

Feb. 29, 2000

Hi! In PR#214 Martin v. Loewis suggests a sizeof function as result of request to python-help. I've followed the thread silently until now. On platforms with virtual memory subsystem this is usually a not an issue. On embedded systems and ancient OSes (like MS-Dos) it is often useful, if applications can estimate how much memory their data consumes. The sizeof() function proposed by Martin is only one possible approach I can think of. Another approach would be encapsulationg the 'malloc/… [View More]

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Safe destruction of recursive objects
by Christian Tismer Feb. 29, 2000

Feb. 29, 2000

Hi Guido, When a user does the following with standard Python: tup = () for i in xrange(100000): tup = (tup, i) del tup # ka-boom He will get a core dump due to stack limitations. Recently, I changed Stackless Python to be safe for any recursive object built from lists, tuples, dictionaries, tracebacks and frames. The implementation is not Stackless Python dependant and very efficient (for my eyes at least). For efficiency, locality and minimum changes to five modules, it is implemented … [View More]as two embracing macroes which are stuffed around the bodies of the deallocator methods, that makes just 3-4 lines of change for every module. (Well, the macro *can* be expanded if you like that more) I can submit patches, but please have a look at the example below, to save me the time in case you don't like it. It works great for SLP. cheers - chris -------------------------------------- Example of modified list deallocator: /* Methods */ static void list_dealloc(op) PyListObject *op; { int i; Py_TRASHCAN_SAFE_BEGIN(op) if (op->ob_item != NULL) { /* Do it backwards, for Christian Tismer. There's a simple test case where somehow this reduces thrashing when a *very* large list is created and immediately deleted. */ i = op->ob_size; while (--i >= 0) { Py_XDECREF(op->ob_item[i]); } free((ANY *)op->ob_item); } free((ANY *)op); Py_TRASHCAN_SAFE_END(op) } This is the original 1.5.2+ code, with two macro lines added. -------------------------------------- Here the macro code (which may of course be expanded) #define PyTrash_UNWIND_LEVEL 50 #define Py_TRASHCAN_SAFE_BEGIN(op) \ { \ ++_PyTrash_delete_nesting; \ if (_PyTrash_delete_nesting < PyTrash_UNWIND_LEVEL) { \ #define Py_TRASHCAN_SAFE_END(op) \ ;} \ else { \ if (!_PyTrash_delete_later) \ _PyTrash_delete_later = PyList_New(0); \ if (_PyTrash_delete_later) \ PyList_Append(_PyTrash_delete_later, (PyObject *)op); \ } \ --_PyTrash_delete_nesting; \ while (_PyTrash_delete_later && _PyTrash_delete_nesting <= 0) { \ PyObject *shredder = _PyTrash_delete_later; \ _PyTrash_delete_later = NULL; \ ++_PyTrash_delete_nesting; \ Py_DECREF(shredder); \ --_PyTrash_delete_nesting; \ } \ } \ extern DL_IMPORT(int) _PyTrash_delete_nesting; extern DL_IMPORT(PyObject *) _PyTrash_delete_later; -- Christian Tismer :^) <mailto:tismer@appliedbiometrics.com> Applied Biometrics GmbH : Have a break! Take a ride on Python's Kaunstr. 26 : *Starship* http://starship.python.net 14163 Berlin : PGP key -> http://wwwkeys.pgp.net PGP Fingerprint E182 71C7 1A9D 66E9 9D15 D3CC D4D7 93E2 1FAE F6DF we're tired of banana software - shipped green, ripens at home [View Less]

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Re: [Python-checkins] CVS: python/dist/src/Objects classobject.c,2.82,2.83
by Greg Stein Feb. 28, 2000

Feb. 28, 2000

I didn't have the heart to keep pestering Moshe, so I delayed a bit on the latest round (and then left town for a few days). As a result, I didn't get a chance to comment on this last patch. There is one problem, and some formatting nits... On Mon, 28 Feb 2000, Guido van Rossum wrote: >... > + static int instance_contains(PyInstanceObject *inst, PyObject *member) > + { > + static PyObject *__contains__; > + PyObject *func, *arg, *res; > + int ret; > + > + if(… [View More]

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Whither cursesmodule?
by Andrew M. Kuchling Feb. 28, 2000

Feb. 28, 2000

On comp.lang.python, "Juergen A. Erhard" <jae(a)ilk.de> wrote about cursesmodule: > Why two versions? Did Oliver forget to submit his patches to Guido > (et al)? Or did Guido not accept them? If so, why not? > > What needs to be done to synchronize the canonical Python and the > Python RPMs? For python-dev readers: Oliver Andrich's Python RPMs contain his enhanced cursesmodule, which supports many ncurses features. The cursesmodule in the Python distribution supports … [View More]

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Re: [Python-checkins] CVS: python/dist/src/Lib ConfigParser.py,1.14,1.15
by Greg Stein Feb. 28, 2000

Feb. 28, 2000

On Mon, 28 Feb 2000, Fred L. Drake wrote: >... > Index: ConfigParser.py > =================================================================== > RCS file: /projects/cvsroot/python/dist/src/Lib/ConfigParser.py,v > retrieving revision 1.14 > retrieving revision 1.15 > diff -C2 -r1.14 -r1.15 > *** ConfigParser.py 1999/10/12 16:12:48 1.14 > --- ConfigParser.py 2000/02/28 20:59:03 1.15 > *************** > *** 293,302 **** > SECTCRE = re.compile( > … [View More]

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Unicode codec names
by M.-A. Lemburg Feb. 28, 2000

Feb. 28, 2000

Hi everybody, As you may have noticed, the latest Unicode snapshot contains a large number of new codecs. Most of them are based on a generic mapping codec which makes adding new codecs a very simple (even automated) task. I've gotten some feedback on the compatibility of the JPython Unicode implementation (actually the underlying Java one) and the new CPython code. Finn Bock mentioned that Java uses a slightly different naming scheme and also has some differences in the code-page-to-Unicode … [View More]mappings. * Could someone provide a list of all default code pages and other encodings that Java supports ? It would be ideal to provide the same set for CPython, IMHO. So far I've got these encodings: cp852.py iso_8859_5.py cp855.py iso_8859_6.py ascii.py cp856.py iso_8859_7.py charmap.py cp857.py iso_8859_8.py cp037.py cp860.py iso_8859_9.py cp1006.py cp861.py koi8_r.py cp1250.py cp862.py latin_1.py cp1251.py cp863.py mac_cyrillic.py cp1252.py cp864.py mac_greek.py cp1253.py cp865.py mac_iceland.py cp1254.py cp866.py mac_latin2.py cp1255.py cp869.py mac_roman.py cp1256.py cp874.py mac_turkish.py cp1257.py iso_8859_10.py raw_unicode_escape.py cp1258.py iso_8859_13.py unicode_escape.py cp424.py iso_8859_14.py unicode_internal.py cp437.py iso_8859_15.py utf_16.py cp737.py iso_8859_2.py utf_16_be.py cp775.py iso_8859_3.py utf_16_le.py cp850.py iso_8859_4.py utf_8.py Encoding names map to these module names in the following way: 1. convert all hyphens to underscores 2. convert all chars to lowercase 3. apply an alias dictionary to the resulting name Thus u"abc".encode('KOI8-R') and u"abc".encode('koi8_r') will result in the same codec being used. * There's also another issue: code pages with names cpXXXX come from two sources: IBM and MS. Unfortunately, some of these pages don't match even though they carry the same name. Could someone verify whether the included maps work on Windows, DOS and Mac platforms as intended ? (Finn reported some divergence between the Java view of things and the maps I created from the ftp.unicode.org site ones.) Thanks, -- Marc-Andre Lemburg ______________________________________________________________________ Business: http://www.lemburg.com/ Python Pages: http://www.lemburg.com/python/ [View Less]

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Re: [Patches] Readline replacement under QNX in myreadline.c
by Guido van Rossum Feb. 28, 2000

Feb. 28, 2000

> This patch for Python 1.52 , /Parser/myreadline.c on QNX using Watcom > C++. > Readline does not work properly . > Using QNX input_line function instead of Linux readline. > ------------------------------------------------------------ > 30,38d29 > < > < #ifdef __QNX__ > < p = input_line( fp, buf, len ); > < if( p ) { > < int n = strlen(p); > < p[n] = '\n'; > < p[n+1] = 0; > < } > < #else > 40d30 > … [View More]

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