Mailman 3 August 2001 - Python-Dev

Re: [Python-Dev] (Idea) subclassable string: path object?
by Jack Jansen Aug. 3, 2001

Aug. 3, 2001

One problem I see is that what you'd really like is to overload + and split and such on path objects. But this creates a problem if you then pass this path object to something that expects old-fashioned strings: if it wants to manipulate that path it will use string operations, which suddenly have different semantics... Recently, Just van Rossum <just(a)letterror.com> said: > Every once in a while I wished for an path object to manipulate file system > paths. Things like > os.… [View More]

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RE: Outdated Misc/cheatsheet
by Simon Brunning Aug. 3, 2001

Aug. 3, 2001

> From: Andrew Kuchling [SMTP:akuchlin@mems-exchange.org] > Misc/cheatsheet is way out of date (the 'access' keyword?). I'd like > to replace it with the text version of Simon Brunning and Richard > Gruet's Python cheatsheet. Issues: Andy, Sounds like a good idea to me. > 1) Simon, do you grant permission to do that? Should I ask Richard, > too? Yes and yes. I've copied Richard in on this. > 2) The new file is significantly larger: 100K instead of just 22K. > … [View More]

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test_quopri is iso-latin-1 centric
by Martin von Loewis Aug. 3, 2001

Aug. 3, 2001

> I think test_quopri is too latin-1 centric. Strictly speaking, there is nothing latin-1 centric in test_quopri.py whatsoever. > For instance, on my Mac, Python source is in MacRoman encoding. CVS > knows all about this, so it happily converts the > latin-1-upsidedown-exclam to a macroman-upsidedown-exclam, and if I > look at the source code I see the same glyph as I see on Unix. This is the problem. Python source code is not in Latin-1; bytes inside strings and comments are "… [View More]

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test results
by Skip Montanaro Aug. 2, 2001

Aug. 2, 2001

On my Mandrake 8.0 laptop I ran make test after grabbing the latest stuff from cvs and wound up with 145 tests OK. 1 test failed: test_linuxaudiodev 14 tests skipped: test_al test_cd test_cl test_dl test_gl test_imgfile test_largefile test_nis test_ntpath test_socketserver test_sunaudiodev test_unicode_file test_winreg test_winsound The linuxaudiodev test never seems to work for me (though I do hear an agonizing wail (is that supposed to be Homer Simpson?) from my … [View More]

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Good news about ExtensionClass and Python 2.2a1
by Neil Schemenauer Aug. 2, 2001

Aug. 2, 2001

After a few tweaks to ExtensionClass and a few small fixes to some of our introspection code I'm happy to say that Python 2.2a1 passes our unit test suite. This is significant since there are about 45000 lines of code (counted by "wc -l") tested by 3569 test cases. Since we use ZODB ExtensionClasses are quite widely used. Merging descr_branch into HEAD sounds like a good idea to me. Well done Guido. I'm going to spend a bit of time trying to rewrite the ZODB Persistent class as a type. … [View More]Attached is a diff of the changes I made to ExtensionClass. Neil --- ExtensionClass.h.dist Tue Jul 31 11:50:39 2001 +++ ExtensionClass.h Tue Jul 31 12:15:21 2001 @@ -143,12 +143,48 @@ reprfunc tp_str; getattrofunc tp_getattro; setattrofunc tp_setattro; - /* Space for future expansion */ - long tp_xxx3; - long tp_xxx4; + + /* Functions to access object as input/output buffer */ + PyBufferProcs *tp_as_buffer; + + /* Flags to define presence of optional/expanded features */ + long tp_flags; char *tp_doc; /* Documentation string */ + /* call function for all accessible objects */ + traverseproc tp_traverse; + + /* delete references to contained objects */ + inquiry tp_clear; + + /* rich comparisons */ + richcmpfunc tp_richcompare; + + /* weak reference enabler */ + long tp_weaklistoffset; + + /* Iterators */ + getiterfunc tp_iter; + iternextfunc tp_iternext; + + /* Attribute descriptor and subclassing stuff */ + struct PyMethodDef *tp_methods; + struct memberlist *tp_members; + struct getsetlist *tp_getset; + struct _typeobject *tp_base; + PyObject *tp_dict; + descrgetfunc tp_descr_get; + descrsetfunc tp_descr_set; + long tp_dictoffset; + initproc tp_init; + allocfunc tp_alloc; + newfunc tp_new; + destructor tp_free; /* Low-level free-memory routine */ + PyObject *tp_bases; + PyObject *tp_mro; /* method resolution order */ + PyObject *tp_defined; + #ifdef COUNT_ALLOCS /* these must be last */ int tp_alloc; @@ -302,7 +338,9 @@ { PyExtensionClassCAPI->Export(D,N,&T); } /* Convert a method list to a method chain. */ -#define METHOD_CHAIN(DEF) { DEF, NULL } +#define METHOD_CHAIN(DEF) \ + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \ + { DEF, NULL } /* The following macro checks whether a type is an extension class: */ #define PyExtensionClass_Check(TYPE) \ @@ -336,7 +374,9 @@ #define PURE_MIXIN_CLASS(NAME,DOC,METHODS) \ static PyExtensionClass NAME ## Type = { PyObject_HEAD_INIT(NULL) \ 0, # NAME, sizeof(PyPureMixinObject), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \ - 0, 0, 0, 0, 0, 0, 0, DOC, {METHODS, NULL}, \ + 0, 0, 0, 0, 0, 0, 0, DOC, \ + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, \ + {METHODS, NULL}, \ EXTENSIONCLASS_BASICNEW_FLAG} /* The following macros provide limited access to extension-class --- ExtensionClass.c.dist Tue Jul 31 11:01:20 2001 +++ ExtensionClass.c Tue Jul 31 12:15:24 2001 @@ -119,7 +119,7 @@ static PyObject *subclass_watcher=0; /* Object that subclass events */ static void -init_py_names() +init_py_names(void) { #define INIT_PY_NAME(N) py ## N = PyString_FromString(#N) INIT_PY_NAME(__add__); @@ -1800,8 +1800,8 @@ if (PyFunction_Check(r) || NeedsToBeBound(r)) ASSIGN(r,newPMethod(self,r)); - else if (PyMethod_Check(r) && ! PyMethod_Self(r)) - ASSIGN(r,newPMethod(self, PyMethod_Function(r))); + else if (PyMethod_Check(r) && ! PyMethod_GET_SELF(r)) + ASSIGN(r,newPMethod(self, PyMethod_GET_FUNCTION(r))); return r; } @@ -3527,7 +3527,7 @@ }; void -initExtensionClass() +initExtensionClass(void) { PyObject *m, *d; char *rev="$Revision: 1.1 $"; [View Less]

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linuxaudiodev
by Charles G Waldman Aug. 2, 2001

Aug. 2, 2001

Skip Montanaro write: > The linuxaudiodev test never seems to work for me (though I do hear an > agonizing wail (is that supposed to be Homer Simpson?) from my laptop's > speakers when it's run). The result is always: > > test test_linuxaudiodev crashed -- linuxaudiodev.error: (16, 'Device or > resource busy') > > The socketserver test works when run manually. Neil Schemenauer replied: > Something has /dev/dsp or /dev/audio open. Are you … [View More]

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Outdated Misc/cheatsheet
by Andrew Kuchling Aug. 2, 2001

Aug. 2, 2001

Misc/cheatsheet is way out of date (the 'access' keyword?). I'd like to replace it with the text version of Simon Brunning and Richard Gruet's Python cheatsheet. Issues: 1) Simon, do you grant permission to do that? Should I ask Richard, too? 2) The new file is significantly larger: 100K instead of just 22K. Is that OK? 3) The reference will need updating for 2.1 and 2.2 changes, but slightly obsolete is better than waaay obsolete. Simon, do you want help updating it for 2.1/2.2? --amk

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linuxaudiodev, ps
by Charles G Waldman Aug. 2, 2001

Aug. 2, 2001

Skip - did you try "fuser /dev/dsp" ?

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Re: [Python-Dev] Parrot -- should life imitate satire?
by Samuele Pedroni Aug. 2, 2001

Aug. 2, 2001

Hi. > > > > > > The point is to put the commonly called things in the vtable in a way that > > > you can avoid as much conditional code as possible, while less common > > > things get dealt with in ways you'd generally expect. (Dynamic lookups > > with > > > caching and suchlike things) > > > >If I'm right, you're designing a object-based VM. > > More or less, yep, with a semi-generic two-arg dispatch for the binary > … [View More]methods. The vtable associated with each variable has a fixed set of > required functions--add with 2nd arg an int, add with second arg a bigint, > add with second arg a generic variable, for example. Basically all the > things one would commonly do on data (add, subtract, multiply, divide, > modulus, some string ops, get integer/real/string representation, copy, > destroy, etc) have entries, with a catchall "generic method call" to > handle, well, generic method calls. A question: when you say variable you mean variable (perl sense of that) or object. It has already been pointed out but it's really confusing from the point of view of python terminology. Will perl6 have only variables which contain objects, truly references to objects like Python or ...? I should repeat that your explanation that assigment is somehow performed calling a method on the "variable" is quiet a strange notion in general, I can imagine having a slot called on assigment that eventually does a copy or return just the object but assigment as an operation on the lvalue is something very peculiar. I know that perl5 assignment is an operator returning an lvalue, is this related? > It's all designed with high-speed dispatch and minimal conditional branch > requirements in mind, as well as encapsulating all the "what do I do on > data" functions. Basically the opcodes generally handle control flow, > register/stack ops, and VM management, while actual operations on variables > is left to the vtable methods attached to the variables. > > I expect things to get mildly incestuous for speed reasons, but I'm OK with > that. :) > > >I don't how > >typical is OO programming in Perl, but in Python that plays a central role, > >if your long run goal is to compile to native code you should have > >a "hard-wired" concept of classes and them like, > > Yep. There's a fast "get name of object's class" and "get pointer to > object's class stash/variable table/methods/subs/<insert generic class > terminology here>". > > > because an operation > >like getting the class of an instance should be as direct and fast as possible > >if you want to use any of the "nice" optimization for a VM for a OO dynamic > >language: > > inline polymorphic caches > > Yup. I'm leaning towards a class based cache for inherited methods and > suchlike things, but I'm not sure that's sufficient if we're going to have > objects whose inheritance tree is handled on a per-object basis. Make sense for the interpreted version, but for speed call-site caches is far more promising when native compiling, but also more complicated. I imagine you already know e.g. the Self project literature. > > customization > > Details? I'm not sure what you're talking about here. Compiling different versions of the same method for example wrt to the receiver type in single dispatch case. See below > > or if/when possible: direct inlining. > > Yep, though the potential to mess with a class' methods at runtime tends to > shoot this one down. (Perl's got similar issues with this, plus a few extra > real nasty optimizer killers) I'm pondering a "check_if_changed" branch > opcode that'll check a method/function/sub's definition to see if it's > changed since the code was generated, and do the inline stuff if it hasn't. > Though that still limits what you can do with code motion and other > optimizations. > > >If any of the high-level OO system can not be used, you have to choose > >a lower level one and map these to it, > >a vtable bytecode mapping model is too underspecified. > > Oh, sure, saying "vtable bytecode mapping model" is an awful lot like > saying "procedural language"--it's informative without actually being > useful... :) I imagine you already know: especially when compiling to native code, it is all a matter of optimizing for the common case, and be prepared to be quiet slow otherwise, especially when dealing with dynamic changes, both in Perl and Python there is no clear distiction from normal ops and dynamic changes to methods... but in any case they are rare compared to the rest. Threading adds complexity to the problem. For the rest is just speed vs. memory, customization is a clear example for that. regards, Samuele Pedroni. [View Less]

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Python API version & optional features
by M.-A. Lemburg Aug. 2, 2001

Aug. 2, 2001

Martin has uploaded a patch which modifies the Python API level number depending on the setting of the compile time option for internal Unicode width (UCS-2/UCS-4): https://sourceforge.net/tracker/?func=detail&aid=445717&group_id=5470&atid=… I am not sure whether this is the right way to approach this problem, though, since it affects all extensions -- not only ones using Unicode. If at all possible, I'd prefer some other means to handle this situation (extension developers are … [View More]

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