Mailman 3 October 2007 - Cplusplus-sig

Wrapping global data
by Matthew Scouten Oct. 3, 2007

Oct. 3, 2007

OK, I can wrap a global function, I can wrap a member function, I can wrap a member variable, But I can't seem to figure out how to wrap a global variable. Maybe I'm just suffering from temporary stupidity. def_readonly() does not exist, def() results in hundreds of cryptic error messages that look like it is trying to wrap a function.

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Py++ question
by Robert O'Callahan Oct. 2, 2007

Oct. 2, 2007

I am trying to use a generate_code.py created by the py++ gui, but I get this error: Traceback (most recent call last): File "generate_code.py", line 40, in ? export() File "generate_code.py", line 37, in export mb.write_module( os.path.join( settings.generated_files_dir, settings.module_name + '.cpp') ) File "/usr/lib/python2.4/site-packages/pyplusplus/module_builder/builder.py", line 311, in write_module file_writers.write_file( self.code_creator, file_name, encoding=self.encoding ) File "/usr/lib/python2.4/site-packages/pyplusplus/file_writers/__init__.py", line 40, in write_file sf.write() File "/usr/lib/python2.4/site-packages/pyplusplus/file_writers/single_file.py", line 27, in write self.write_file( self.file_name, self.extmodule.create(), encoding=self.encoding ) File "/usr/lib/python2.4/site-packages/pyplusplus/file_writers/writer.py", line 124, in write_file f.write( unicode( fcontent_new, encoding ) ) TypeError: decoding Unicode is not supported Should I be writing the code generator from scratch? -Rob

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Re: [C++-sig] Announcing pybindgen
by Gustavo Carneiro Oct. 1, 2007

Oct. 1, 2007

(manually replying from copy-pasting the archives because my c++-sig subscription was disabled by accident). Nat Goodspeed wrote: >Gustavo Carneiro wrote: >> Hello all, >> >> I'd like to announce a new project for producing python extensions, >> called PyBindGen. It follows a radical new path for Python bindings >> generation: it is itself written in (gasp!) Python! And it does not >> even use C++ templates at all! :-) >Interesting! I would be curious to see you contrast it with the Py++ >project: > >http://www.language-binding.net/pyplusplus/pyplusplus.html > >to get a sense of when I might choose to use one vs. the other. I know Py++. You cannot compare Py++ with PyBindGen. I would say that PyBindGen replaces Boost.Python. Py++ is a layer on top of Boost.Python. Py++ generates Boost.Python module definition sources through automatic scanning of C++ header files. PyBindGen lacks the header files scanning feature that Py++ provides, and I really miss that feature in PyBindGen. I hope that someone (maybe me) finds time to work on that for PyBindGen, some day... I'm not sure if Py++ is modular enough to be able to receive a different code generation backend besides Boost.Python (Roman, feel free to comment :). Although I like Py++ a lot, I really hate Boost.Python. Maybe it's because of my lack of skill in understanding C++ templates, but I feel like Boost.Python hides too many details underneath a layer of cryptic to follow set of C++ templates, while I need to see the generated code in order to check that memory management details are being declared and implemented correctly. In addition, to compile Boost.Python based bindings your users need to have the boost python library and header files installed. In contrast, PyBindGen generated extensions only require python development header files in order to compile, nothing more. I also think Boost.Pythonextensions compile to rather large modules... Regards, -- Gustavo J. A. M. Carneiro INESC Porto, Telecommunications and Multimedia Unit "The universe is always one step beyond logic." -- Frank Herbert

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