Mailman 3 January 2008 - Python-Dev

Changing PyAPI_DATA(type) into PyAPI_DATA(type, variablename)?
by Jukka.P.Laurila＠nokia.com Jan. 9, 2008

Jan. 9, 2008

Hello, python-dev! One-liner summary: Would it be possible to change PyAPI_DATA(type) into PyAPI_DATA(type, variablename) to help portability to funny platforms? We've been working on porting the Python 2.5.1 core to the Symbian S60 smartphone platform. Unlike the previous 2.2.2 port, this time we're trying really hard to keep our changes clean so that they could some day be accepted into the main Python codebase. One problem we've encountered is that Symbian doesn't properly support … [View More]exporting data from a DLL, and instead we must export a function that returns a pointer to the variable in question, and hide this from client applications using a macro: In a generated header, dataexports.h: #define Py_Verbose (*__DATAEXPORT_Py_Verbose()) extern __declspec(dllimport) int *__DATAEXPORT_Py_Verbose(); In a generated C file, dataexport.c: __declspec(dllexport) int *__DATAEXPORT_Py_Verbose() { return &Py_Verbose; } dataexports.h is included into Python.h when Py_BUILD_CORE isn't defined. Now, the problem is that we haven't figured out any way to define the PyAPI_DATA macro in its one-argument form so that this scheme would work, since when compiling client applications we'd like all the PyAPI_DATA declarations to expand to nothing, and get the declarations from dataexport.h instead. The best solution we've come up with is to change PyAPI_DATA into a two-argument form and change all declarations accordingly. Whether to export data with this mechanism or directly could be a pyconfig.h option, DATA_EXPORT_AS_FUNCTIONS (or HAVE_DATA_EXPORT?). Briefly the changes would touch: pyport.h: #ifdef Py_BUILD_CORE #define PyAPI_DATA(RTYPE,NAME) extern RTYPE NAME // data item not exported from the Python DLL #else #define PyAPI_DATA(RTYPE,NAME) // PyAPI_DATA can be blank since then the real declarations come from dataexports.h #endif pydebug.h and all other files that declare exported data: PyAPI_DATA(int) Py_VerboseFlag; --> PyAPI_DATA(int, Py_VerboseFlag) In addition, complex types such as function pointers and arrays would need to be typedef'ed, e.g.: PyAPI_DATA(char) *(*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, char *); --> typedef char *(*t_PyOS_ReadlineFunctionPointer)(FILE *, FILE *, char *); PyAPI_DATA(t_PyOS_ReadlineFunctionPointer, PyOS_ReadlineFunctionPointer) and multiple PyAPI_DATA declarations on a line would need to be split to several PyAPI_DATA declarations. If this change isn't acceptable then we'd pretty much have to fork this aspect of the interpreter - either by just maintaining a patch that's applied to the headers or by making a preprocessor that fixes the headers on the fly. Does this sound reasonable? Any better ideas? -Jukka [View Less]

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Re: [Python-Dev] Coverity Scan, Python upgraded to rung 2
by Christian Heimes Jan. 9, 2008

Jan. 9, 2008

Joseph Armbruster wrote: > Christian, > > Is there any way you (or someone else) could post up the results? It > looks like you need a log in to check them out. I haven't figured out how to access the results. Who has a login and access to the site? Christian

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Import by filename with __import__ ?
by Christian Heimes Jan. 9, 2008

Jan. 9, 2008

Today I stumbled about an unknown and undocumented (?) feature. At least it's not documented in our docs. __import__ can import a module by file name: >>> open("/tmp/example.py", "w").write("test = 23\n") >>> mod = __import__("/tmp/example") >>> mod <module '/tmp/example' from '/tmp/example.py'> >>> mod.__name__ '/tmp/example' >>> mod.__file__ '/tmp/example.py' >>> mod.test 23 Is it just a coincidence? Is it a desired feature? Why … [View More]

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Extracting variables from string.Template objects
by Isaac Morland Jan. 9, 2008

Jan. 9, 2008

I found myself wanting to obtain the variables from a string.Template object. The situation is that part of input consists of a filename template, and I want to make sure that all the parameter values I have are actually represented in the filename template. So: def templateVariables (template): """Extract the variable names from a string.Template. Returns a tuple of all variable names found in the template, in the order in which they occur. If an invalid escape sequence … [View More]

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Backport PEP 3129: Class Decorators
by Raymond Hettinger Jan. 8, 2008

Jan. 8, 2008

This seems like something that could reasonably be added to Py2.6. Raymond

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test_sys failures
by Guido van Rossum Jan. 8, 2008

Jan. 8, 2008

When I build from scratch and run most tests (regrtest.py -uall) I get some strange failures with test_sys.py: test test_sys failed -- Traceback (most recent call last): File "/usr/local/google/home/guido/python/py3kd/Lib/test/test_sys.py", line 302, in test_43581 self.assertEqual(sys.__stdout__.encoding, sys.__stderr__.encoding) AssertionError: 'ascii' != 'ISO-8859-1' The same test doesn't fail when run in isolation. Interestingly, I saw this with 2.5 as well as 3.0, but not with 2.6! … [View More]

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pkgutil, pkg_resource and Python 3.0 name space packages
by Raymond Hettinger Jan. 8, 2008

Jan. 8, 2008

>> And then extend this to any other >> package that we consider creating? Otherwise leave it out? How would >> that follow for sqlite since that is not going to get any shorter >> thanks to a package? Should it still go into the package for >> organizational purposes? > If you're asking me, the "organizational purpose" is 100% misguided. It is my hope that there will be a great deal of restraint in the effort to group modules into packages in Py3.0. For … [View More]

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Re: [Python-Dev] pkgutil, pkg_resource and Python 3.0 name space packages
by Phillip J. Eby Jan. 8, 2008

Jan. 8, 2008

At 04:23 PM 1/6/2008 -0800, Guido van Rossum wrote: >Regarding using common words, either the stdlib grabs these, or >*nobody* gets to use them (for fear of conflicting with some other 3rd >party package grabbing the same). This isn't quite true; a standalone Python application that isn't extensible doesn't need to worry about this. And it's standalone apps that are most likely to claim these common words. (For example, until recently, Chandler's database library packages were in … [View More]

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Do we need both Trac and Roundup?
by skip＠pobox.com Jan. 7, 2008

Jan. 7, 2008

A ticket I opened on Roundup about a website issue some time ago was closed today. It was related to a different topic, but in the discussion I wrote: Is there some reason at this point that we need to maintain two separate trackers? A ton of work went into making our Roundup instance what the key players wanted. Why not use it to track website issues as well? With them separate you have two communities of maintainers and triage folks who are mostly disjoint. I … [View More]

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Re: [Python-Dev] pkgutil, pkg_resource and Python 3.0 name space packages
by Phillip J. Eby Jan. 7, 2008

Jan. 7, 2008

At 02:10 PM 1/6/2008 -0800, Brett Cannon wrote: >My question becomes whether we want to allow something like this even >if we explicitly state people should not use this mechanism to >override pre-existing modules. Do we want people tossing stuff into >the 'databases' package, or should the packages in the stdlib be >considered sacred? This is actually an excellent point, given that the actual intended use of namespace packages is to allow an *organization* to control a … [View More]

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