Mailman 3 May 2009 - Cplusplus-sig

boost::python embedding error - runtime - Mac OS X - 1.38
by Igor Karpov Oct. 1, 2014

Oct. 1, 2014

Hi, I am trying to run the following program: #include <iostream> #include <Python.h> #include <boost/python.hpp> using namespace boost::python; using namespace std; int main(int argc, char** argv) { { // Using Python/C Py_Initialize(); PyObject* main_module = PyImport_ImportModule("__main__"); PyObject* globals = PyEval_GetGlobals(); PyObject* locals = PyEval_GetLocals(); PyRun_SimpleString("print 'Hello World, from Python/C!'\n"); Py_Finalize(); } { // Using boost::python Py_Initialize(); object main_module = import("__main__"); object main_namespace = main_module.attr("__dict__"); try { object ignored = exec("print 'Hello World, from boost::python!'\n", main_namespace); Py_Finalize(); } catch (error_already_set const& e) { PyErr_Print(); return 1; } } return 0; } on Linux (both x86 and x86_64), with Ubuntu's default version of Boost (1.34.1) installed, I am able to do so as expected: $ ./embed Hello World, from Python/C! Hello World, from boost::python! on Mac OS X, I get a runtime error: $ ./embed Hello World, from Python/C! Bus Error Running with gdb, this is the stack trace: Hello World, from Python/C! Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x00000000 0x00000000 in ?? () (gdb) where #0 0x00000000 in ?? () #1 0x00bb618f in PyEval_GetGlobals () #2 0x00bce0dd in PyImport_Import () #3 0x00bce2b0 in PyImport_ImportModule () #4 0x008127d4 in boost::python::import (name=@0xbffff4a8) at libs/python/src/import.cpp:20 #5 0x00004446 in main (argc=1, argv=0xbffff510) at embed.cc:22 For this Mac, boost version is latest (1.38) and python version is: Python 2.5.4 (r254:67917, Dec 23 2008, 14:57:27) [GCC 4.0.1 (Apple Computer, Inc. build 5363)] on darwin Is this a bug? I attached the source and the cmake file I am using to build, for convenience. Thanks, --Igor.

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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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Getting object for PyObject (reference counting)
by Murray Cumming Feb. 11, 2010

Feb. 11, 2010

I can't find any definitive documentation that tells me how I should get a boost::python::object to wrap an existing PyObject*. I guess that there's a way to do it that uses an existing reference, and a way that takes an extra reference. -- murrayc(a)murrayc.com www.murrayc.com www.openismus.com

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pygccxml and multidimensional arrays
by Davidson, Josh June 19, 2009

June 19, 2009

Machine: x86_64 running RH EL 5.0 Pygccxml version 1.0.0 Gcc-xml version 0.9.0 If I create a struct similar to: typedef struct { uint16_t a[4][2][3]; } blah; And use pygccxml to parse it, the type attribute for the field "a" is set to: uint16_t[3][2][4]. Does anyone know why the dimensions are reversed?

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[Py++] wrapping boost python types fails
by Werner Joergensen May 31, 2009

May 31, 2009

I narrowed down a failure with pyplusplus to this short example: ---------8<---- test.hpp ----- #include "boost/python.hpp" --------->8--------- ---------8<---- generator.py ----- import os from pyplusplus import module_builder mb = module_builder.module_builder_t( files=["test.hpp"], include_paths=["/usr/include/python2.6"] ) mb.build_code_creator( module_name='testmodule' ) mb.code_creator.user_defined_directories.append( os.path.abspath('.') ) mb.split_module("split") mb.write_module( os.path.join( os.path.abspath('.'), 'generated.cpp' ) ) --------->8--------- Running "python generator.py" gives these errors: ---------8<---- output ----- ... pygccxml.parser.source_reader.gccxml_runtime_error_t: Error occured while running GCC-XML: In file included from /usr/local/include/boost-1_39/boost/python.hpp:60, from test.hpp:1: /usr/local/include/boost-1_39/boost/type.hpp:14: internal compiler error: Segmentation fault Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://gcc.gnu.org/bugs.html> for instructions. --------->8--------- I need to use the python objects like list, str, tuple in my python extension modules. So can you help me to get the example running? I tried it on two different systems, one with gcc 4.2.4 and one with gcc 4.3.3. Other relevant packages are: gccxml 0.9 (cvs from 2008-05-30), boost 1.39.0, pygccxml 1.0, pyplusplus 1.0. Can you tell me which combination of these packages can compile the short example? Thanks Werner

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[Py++] incomplete type and forward declaration
by Werner Joergensen May 31, 2009

May 31, 2009

How can I process such a file classA.hpp using a code generator like http://www.language-binding.net/pyplusplus/documentation/tutorials/module_b… ----------8<---- classA.hpp ------ class B; class A{ public: B& dontCareAboutB(){ /*return C::getB();*/ }; void doSomething(){}; }; ----------8<---------- This class compiles fine with just "g++ -c classA.hpp", but applying the pyplusplus code generator followed by bjam throws several errors: ... /opt/boost_1_39_0/boost/python/type_id.hpp:89: error: invalid use of incomplete type ‘struct B’ ./classA.hpp:1: error: forward declaration of ‘struct B’ ... If I replace the first line with "class B{}", making B a comple, empty class, this example succeeds. But then I run into more troubles if I add the actual definition of the real class B from another header file to the python module. Does a solution with pyplusplus exist, where I don't need to modify the classA.hpp header file? Thanks Werner

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libboost_python-gcc43-mt.so or without "mt"?
by Werner Joergensen May 29, 2009

May 29, 2009

Dear list participants, I have installed boost including the python lib using the boostrap.sh installation script, and now I have the following libraries under /lib (linux system): libboost_python-gcc43-mt-1_39.a libboost_python-gcc43-mt-1_39.so libboost_python-gcc43-mt-1_39.so.1.39.0 libboost_python-gcc43-mt.a libboost_python-gcc43-mt.so However when I build a python extension module with bjam, and when I import the newly built module in python, the problem is: $ ipython In [1]: import myModule ImportError: libboost_python-gcc43-1_39.so.1.39.0: cannot open shared object file: No such file or directory Of course, I can copy and rename the mt-libraries to the expected library name. But is there a possibility to build the python extension so that the exististing libboost_python-gcc43-mt.so will be linked instead of some other name? Can I configure which libboost_python will be used somewhere in boost-build.jam or user-config.jam or Jamroot? Thanks Werner

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Derived classes problem
by hessiess＠hessiess.com May 29, 2009

May 29, 2009

I am trying to create a python wrapper for the quad-ren graphics engine, which relies heavily on derived classes. The problem is that I cannot create derived classes in python and pass them to the C++ objects without getting the following error: Traceback (most recent call last): File "test.py", line 79, in <module> quad3.set_event_receiver(event) Boost.Python.ArgumentError: Python argument types in qr_scene_node.set_event_receiver(qr_quad, ev_receiver) did not match C++ signature: set_event_receiver(qr_scene_node {lvalue}, qr_event_receiver*) ==================================================================== C++ ==================================================================== #include <boost/python.hpp> #include <quad-ren/quad-ren.h> using namespace boost::python; struct qr_scene_node_w : qr_scene_node, wrapper<qr_scene_node> { void on_register() { this->get_override("on_register")(); } void on_render() { this->get_override("on_render")(); } void on_drop() { this->get_override("on_drop")(); } }; struct qr_event_receiver_w : qr_event_receiver, wrapper<qr_event_receiver> { bool on_event(qr_event *event, qr_scene_node *node, float time_delta) { this->get_override("on_event")(); } }; BOOST_PYTHON_MODULE(qrpy) { class_<vector2d_i>("vector2d_i") .def(init<float, float>()) .def_readwrite("X", &vector2d_i::X) .def_readwrite("Y", &vector2d_i::Y); class_<vector2d_f>("vector2d_f") .def(init<float, float>()) .def_readwrite("X", &vector2d_f::X) .def_readwrite("Y", &vector2d_f::Y); class_<qr_resource_manager>("qr_resource_manager"); class_<qr_renderer>("qr_renderer") .def(init<vector2d_i, float, bool, vector2d_i>()) .def("get_resource_manager", &qr_renderer::get_resource_manager, return_value_policy<reference_existing_object>()) .def("run", &qr_renderer::run) .def("drop", &qr_renderer::drop) .def("set_total_layers", &qr_renderer::set_total_layers) .def("set_window_title", &qr_renderer::set_window_title) .def("get_time_delta", &qr_renderer::get_time_delta) .def("get_ticks", &qr_renderer::get_ticks) .def("get_fps", &qr_renderer::get_fps) .def("set_camera_location", &qr_renderer::set_camera_location) .def("get_camera_location", &qr_renderer::get_camera_location) .def("get_pix_size", &qr_renderer::get_pix_size) .def("set_bg_sprite", &qr_renderer::set_bg_sprite) .def("get_bg_sprite", &qr_renderer::get_bg_sprite, return_value_policy<reference_existing_object>()); class_<qr_scene_node_w, boost::noncopyable>("qr_scene_node", no_init) .def("register_node", &qr_scene_node_w::register_node) .def("drop", &qr_scene_node_w::drop) .def("set_location", &qr_scene_node_w::set_location) .def("get_location", &qr_scene_node_w::get_location) .def("set_size", &qr_scene_node_w::set_size) .def("get_size", &qr_scene_node_w::get_size) .def("set_rotation", &qr_scene_node_w::set_rotation) .def("get_rotation", &qr_scene_node_w::get_rotation) .def("set_layer", &qr_scene_node_w::set_layer) .def("get_layer", &qr_scene_node_w::get_layer) .def("set_sprite", &qr_scene_node_w::set_sprite) .def("get_sprite", &qr_scene_node_w::get_sprite, return_value_policy<reference_existing_object>()) .def("set_event_receiver", &qr_scene_node_w::set_event_receiver) .def("get_event_receiver", &qr_scene_node_w::get_event_receiver, return_value_policy<reference_existing_object>()) .def("set_frame", &qr_scene_node_w::set_frame) .def("get_frame", &qr_scene_node_w::get_frame) .def("add_polygon", &qr_scene_node_w::add_polygon) .def("clear_mesh", &qr_scene_node_w::clear_mesh) .def("on_register", &qr_scene_node_w::on_register) .def("on_render", &qr_scene_node_w::on_render) .def("on_drop", &qr_scene_node_w::on_drop); class_<qr_event_receiver_w, boost::noncopyable>("qr_event_receiver", no_init) .def("on_event", &qr_event_receiver_w::on_event); class_<qr_quad, bases<qr_scene_node> >("qr_quad") .def(init<qr_resource_manager* , bool>()); } ==================================================================== Python ==================================================================== import qrpy false = bool(0) true = bool(1) #create renderer + get resource manager renderer = qrpy.qr_renderer(qrpy.vector2d_i(4, 3), 10, false, qrpy.vector2d_i(0, 0)) res_man = renderer.get_resource_manager() #event receiver class ev_receiver(qrpy.qr_event_receiver): def __init__(self): return def on_event(self, event, node, time_delta): print event event = ev_receiver() quad = qrpy.qr_quad(res_man, 0) quad.set_event_receiver(event) #error

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problems building a pyd under vc++ with distutils
by Juan Manuel Martinez Caamaño May 29, 2009

May 29, 2009

I'm under vc++ 9.0 and I'm having problem when trying to build a simple *.pyd... (using distutils) When I build the dll from the IDE it produces a DLL (not a *.pyd) and no compiler or linker errors. But when I use distutils it just output a lot of errors... I can't find the problem... /*-----------------pydll.cpp:------------------*/ #include <boost/python.hpp> #include <string> using namespace boost::python; __declspec(dllexport) std::string greet() { return "Hello Python"; }; BOOST_PYTHON_MODULE(hello) { def("greet", greet); } -------------------------------------------------------------- #setup.py from distutils.core import setup, Extension module1 = Extension('hello', sources = ["pydll.cpp"]) setup (name = 'pydll', version = '1.0', description = 'This is a demo package', ext_modules = [module1]) ------------------------------------------------------------- (under visual studio 2008, python 2.6, boost 1.38.0) Thank you Juan

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