Mailman 3 January 2008 - Cplusplus-sig

CMake and getting starting with boost.python
by Braddock Gaskill Aug. 5, 2011

Aug. 5, 2011

Yesterday I became a boost.python user, after years of heavy SWIG usage. I would have started using boost.python years ago except for the bjam learning curve. I spent hours TRYING on multiple occasions, but got lost every time trying to get the page one example to build with bjam. Here is how to build the "greet" example with a four line CMake file: cat >>CMakeLists.txt <<EOF LINK_LIBRARIES(boost_python) INCLUDE_DIRECTORIES("/usr/include/python2.5") LINK_DIRECTORIES("/usr/lib/python2.5") # Not needed? ADD_LIBRARY(hello SHARED hello.cpp) EOF You WILL have to `mv libhello.so hello.so` after building. Works for me under Ubuntu Linux 6.10 after apt-get install cmake python2.5-dev boost-python-dev cmake make mv libhello.so hello.so ipython In [1]: import hello In [2]: hello.greet() Out[2]: 'hello, world' Boost.Python has been a joy to learn and use since I got past bjam. I had a moderately large API wrapped in just my first couple hours of learning (less time than I spent messing with bjam). Any additional advice for using CMake to build boost.python? Braddock Gaskill

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How to import a boost::python dll in windows?
by ichijoji Aug. 5, 2011

Aug. 5, 2011

I'm trying to port some research code that uses boost::python to expose a library to python to windows, but I'm having trouble importing the dll into python. I'm compiling using msvc 2005 and using python 2.5, but when I try to import the module I get this: Traceback (most recent call last): File "main.py", line 1, in <module> import object File "c:\code\sge\code\scripts\object.py", line 1, in <module> import sge ImportError: No module named sge My module is named sge and I'm compiling to sge.dll. Is there some obvious reason why python wouldn't be able to find my dll? When I compile on linux into an so this code works fine. -- View this message in context: http://www.nabble.com/How-to-import-a-boost%3A%3Apython-dll-in-windows--tf3… Sent from the Python - c++-sig mailing list archive at Nabble.com.

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Base class defined in other header file not included in bp::bases<>
by Haridev, Meghana Sept. 14, 2008

Sept. 14, 2008

Hi Folks, I'm having some trouble generating boost-python wrapper code using pyplusplus for a derived class which has one of its base classes defined in another file. Simple scenario: mydir/ other.hpp: class baseB{ }; hierarchy.hpp: #include "other.hpp" class baseA{ }; class derivedC: public baseA, public baseB{ }; generate_code.py: import os from pyplusplus import module_builder mb = module_builder.module_builder_t( files=['hierarchy.hpp'] ) mb.build_code_creator( module_name='inherit' ) mb.code_creator.user_defined_directories.append( os.path.abspath('.') ) mb.write_module('boost_hierarchy.cpp') ------------------------------------------------------------------------ ------------------------------------------------- Generated code (boost_hierarchy.cpp) looks like this: // This file has been generated by pyplusplus. #include "boost/python.hpp" #include "hierarchy.hpp" namespace bp = boost::python; BOOST_PYTHON_MODULE(inherit){ bp::class_< baseA >( "baseA" ); bp::class_< derivedC, bp::bases< baseA > >( "derivedC" ); } How can I get pyplusplus to add 'baseB' to bp::bases<> for 'derivedC' class when 'baseB' class is defined in another file (present in the same directory or different directory)? When I move the definition of 'baseB' class to hierarchy.hpp, boost wrapper for 'derivedC' is correctly generated as: bp::class_< derivedC, bp::bases< baseA, baseB > >( "derivedC" ); Thanks, -Meghana.

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ANNOUNCE: PyBindGen 0.8
by Gustavo Carneiro June 3, 2008

June 3, 2008

The other day I released PyBindGen 0.8. Main news is that it features a new experimental header file scanner based on pygccxml (i.e., it's similar to py++ in scope, if not in maturity, but does not use boost.pythonunderneath). == What == PyBindGen is a Python module that is geared to generating C/C++ code that binds a C/C++ library for Python. It does so without extensive use of either C++ templates or C pre-processor macros. It has modular handling of C/C++ types, and can be easily extended with Python plugins. The generated code is almost as clean as what a human programmer would write, and does not depend on any library or header files besides Python itself. == Where == https://launchpad.net/pybindgen/ == NEWS == - Support C++ instance attributes through getter/setter methods - Support functions as methods of C++ classes - Support the PyObject* type - Support unsigned int, C strings (char*) (from Mark Lee) - Add basic support for enum types - New experimental automatic module generator based on C/C++ header file scanner and annotations in comments, using pygccxml - Some bug fixes -- 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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Raoul Gough's container suite with svn boost-trunk boost.python?
by John Reid May 18, 2008

May 18, 2008

Has anyone tried using Raoul's container suite with the svn boost-trunk? I'm getting the following error: C:\Dev\ThirdParty\boost\boost-trunk\boost/python/detail/caller.hpp(236) : error C2903: 'extract_return_type' : symbol is neither a class template nor a function template C:\Dev\ThirdParty\boost\boost-trunk\boost/python/detail/caller.hpp(232) : while compiling class template member function 'boost::python::detail::py_func_sig_info boost::python::detail::caller_arity<2>::impl<F,Policies,Sig>::signature(void)' with [ F=boost::python::list (__cdecl *)(std::vector<biopsy::binding_hit> &,boost::python::indexing::slice), Policies=boost::python::indexing::detail::postcall_override<boost::python::indexing::default_container_policies>, Sig=boost::mpl::vector3<boost::python::list,std::vector<biopsy::binding_hit> &,boost::python::indexing::slice> ] So the problem seems to be there is no extract_return_type in boost::python::indexing::detail::postcall_override<boost::python::indexing::default_container_policies> If I remember correctly, I've installed Roman's version by copying it into boost/python/suite/indexing John.

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'iteritems', 'iterkeys' and 'itervalues' in dict
by Nindi Singh April 11, 2008

April 11, 2008

Apolgies for not putting the subject line in my last email. In the Boost.Python dict class there are methods 'iteritems', 'iterkeys' and 'itervalues' all returning objects. How exactly are you supposed to use these objects (iterators) ? ___________________________________________________________ Inbox full of spam? Get leading spam protection and 1GB storage with All New Yahoo! Mail. http://uk.docs.yahoo.com/nowyoucan.html

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Python Packages from embedded interpreter
by theY4Kman Feb. 13, 2008

Feb. 13, 2008

I'm embedding Python into a C/C++ application and it has an enormous amount of functions I wish to be accessible in Python. Right now, I have a module named "sourcemod" initialized and running. It has its own functions that can be called by importing the module. However, I want these functions spread out in different modules in "sourcemod", turning "sourcemod" into a package. For example, the user should be able to "import sourcemod" and use " sourcemod.console.PrintToConsole('Hello, World!')". I've been searching everywhere, I've gone through the Python/C API reference, the Embedding and Extending Python document, the #python channel on EFnet, and other people's source code. None of the pages I've found shine any light on how to write a Python package directly from C/C++. Thanks, Zach Kanzler

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missing to_python converter for wchar_t
by progetto dex Feb. 1, 2008

Feb. 1, 2008

Hi all, it seems that I'm facing a well-known problem (I've found some messages dated 2006 or earlier), but maybe in the near past something has changed... I'm wrapping a third party API that uses "const wchar_t* const" arguments, and Python says that a converter is missing. Before creating a layer to convert from/to std::wstring, I post a stripped down example. First, the C++ stuff: // C++ #include <boost/python.hpp> using namespace boost::python; class Receiver { public: virtual void Receive(const wchar_t* const message) { } }; class Sender { Receiver& receiver; public: Sender(Receiver& r) : receiver(r) { } void Send() { receiver.Receive(L"test message"); } }; struct PyReceiver : Receiver { PyObject* self; PyReceiver(PyObject* s) : self(s) { } void Receive(const wchar_t* const message) { return call_method<void>(self, "Receive", message); } void Receive_default(const wchar_t* const message) { return this->Receiver::Receive(message); } }; BOOST_PYTHON_MODULE(MyModule) { class_<Receiver, PyReceiver, boost::noncopyable>("Receiver") .def("Receive", &Receiver::Receive, &PyReceiver::Receive_default) ; class_<Sender, boost::noncopyable>("Sender", init<Receiver&>()) .def("Send", &Sender::Send) ; } Now, a trivial Python test case: #python import MyModule class Receiver(MyModule.Receiver): def Receive (self, msg): print "MSG: " + msg r = Receiver() s = MyModule.Sender(r) s.Send() If I supply a to_python wchar_t converter, only the first letter of the message is printed. I'm I missing something? Best regards, Dex

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Dreamworks Animation Opportunity--Pipeline Engineer
by Norman, Tim Jan. 30, 2008

Jan. 30, 2008

Production or Pipeline (Python) Engineer-Maya or Houdini The Production Engineering group designs, implements, and maintains software that "glues" together the software and data used in the creation of animated feature films. Production engineers understand the entire computer animation process and use that knowledge to develop the DreamWorks global animation pipeline. We are seeking a highly motivated person with experience in both software development and in computer animation production. As a production engineer, you will: * Maintain the existing software systems used in the production of our films * Enhance, modify, and redesign the systems to accommodate the ever-changing requirements of production * Interact with animators and technical directors to solve technical production issues * Use your understanding of computer animation to come up with creative solutions to difficult technical problems Your software development experience must include: * Large software systems * Extensive scripting in Python or Perl (preferably both) * Object oriented C++ experience * UNIX/Linux development Additionally, you must have: * Excellent problem solving and customer service skills * Outstanding attention to detail and following through on tasks * Ability to handle a variety of tasks and personality types * Strong verbal and written communication skills * Enthusiasm for computer animation and/or CG in films We also prefer: * Experience in the computer animation industry * Knowledge of CG software such as Maya, Houdini, or Shake * Shell scripting (csh, tcsh, sh) ability * Knowledge of relational database concepts * System administration skills You must have achieved at least a bachelors degree in computer science. A masters is preferred. Tim Norman Dreamworks Animation Ph 818. 695. 7801 Fax 818. 695. 6210 www.dreamworksanimation.com<http://www.dreamworksanimation.com/> [http://www.dreamworksanimation.com/interact/signatures/shrek_puss1.gif]<http://www.shrek.com/>

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Best way to register shared_ptr<const T>
by Andrea Jan. 26, 2008

Jan. 26, 2008

Hi, I've run into the problem of registering a shared_ptr<const T>. I've found a workaround using a const_cast in get_pointer. I've also read that there exist a patch to implement a proper fix. Unfortunately I cannot find more details on that. Could someone please quick list pros and cons of both approaches. I am a bit uncomfortable about const_casting, but I cannot understand if it is just a way to please the compiler or something deeper. Andrea

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