Mailman 3 September 2013 - 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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sendkeys method
by sam Sept. 30, 2013

Sept. 30, 2013

Hello, Is there away(method) in C/C++ programming that make the software think that someone pressed the OK button, similar to sendkeys in VBS (WshShell.SendKeys ("{Enter}")) Thank you, Sam

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Boost python simple interfacing
by Kassiopi Kassiopi2 Sept. 27, 2013

Sept. 27, 2013

Hi, I want to call a c++ function from an embedded python shell, using boost python. All the examples I've seen online describe how to expose a whole class or some functions, but all cases refer to *standalone* parts of code. My case is different though. The function I want to expose is not standalone, and has a dependency: ------- start of documentModule.cpp -------- #include <commandManager.hpp> #include <boost/python.hpp> void newDocument( bool makeActive ) { // depends on commandManager here GetCommandMananager()->submitCommand( new newDocumentCmd( makeActive ) ); } BOOST_PYTHON(documentModule) { using namespace boost::python; def( "newDocument", myCadLib::pythonCommands::newDocument, arg("makeActive") ); } ------- end of documentModule.cpp -------- In reality the situation is more complicated and there are more dependencies than the one mentioned above. After generating a .so file with distutils, when I start my application and I attempt to load the module (.so file) in the embedded python shell I get an undefined symbols error complaining about the commandManager class. Of course this is a reasonable request from python and I understand that. However, I don't really care to generate a standalone python module per se. I just want it to work in my application's embedded python shell. Additionally, it wouldn't be meaningful to have the commandManager class exposed as well, since this is part of my applications internal structure. Is what I am asking possible with boost python? In the past I have used SWIG for that, and it generated some additional .cpp and .h files, as well as a .py module. I can live with generating additional source and header files if it is an issue for boost python and I don't care to have a standalone python module, as long as it works inside my application. I couldn't find anything online as well. All examples I could find where similar to the boost python tutorial, with standalone parts of code. Thank you in advance.

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memory leak with __iadd__
by Neal Becker Sept. 26, 2013

Sept. 26, 2013

I've been trying to track down a memory leak. When I use the following: .def ("__iadd__", &hist_t::operator+=, bp::return_self<>()) I have a leak. When changed to: .def (bp::self += hist_t::value_type()) there is no leak. Any ideas? I suppose I maybe should just start using the latter style and forget the former.

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Use alternative launcher for bpl-test rule
by John Reid Sept. 24, 2013

Sept. 24, 2013

Hi, I'm having some problems asking boost.build to start the debugger or valgrind when it runs some of my python extension bpl-test rules. I saw in the boost.build code some comments that suggests it hijacks the testing.launcher feature which I thought would be the way to do this. Does anyone know if it is possible and what I should be doing? Thanks, John.

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boost.python: Is a way to auto-fill __dict__ attribute?
by Q Q Sept. 19, 2013

Sept. 19, 2013

Hi, The python objects exposed from C++ classes via boost.python have empty __dict__ attributes. I generated python wrappers using py++. Can I access __dict__ attributes for boost.python objects? Thanks.

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Py++: How to pickle a boost.python object?
by İsmail SAVAŞKAN Sept. 17, 2013

Sept. 17, 2013

Hi, Is it possible to pickle an object loaded from a c++ library which contains py++ auto-generated code? For example a c++ struct: struct Coordinate { int x; int y; }; And its wrapper: BOOST_PYTHON_MODULE(pyplusplus_test){ bp::class_< Coordinate >( "Coordinate" ) .def_readwrite( "x", &Coordinate::x ) .def_readwrite( "y", &Coordinate::y ); } I built pyplusplus_test.so libray. Then I wrote a script such as: import sys import pickle sys.path.append('.') import pyplusplus_test cord = pyplusplus_test.Coordinate() cord.x = 23 cord.y = -11 pickle.dumps(cord) But it failed. The message is "RuntimeError: Pickling of "pyplusplus_test.Coordinate" instances is not enabled (http://www.boost.org/libs/python/doc/v2/pickle.html)" I know that I can arrange generated code adding def_pickle() calls. But I want to generate wrappers automatically. Any suggestion? Thanks. Bu e-posta mesajı ve ekleri gönderildiği kişi ya da kuruma özeldir ve gizlidir. Ayrıca hukuken de gizli olabilir. Hiçbir şekilde üçüncü kişilere açıklanamaz ve yayınlanamaz. Mesajın yetkili alıcısı değilseniz hiçbir kısmını kopyalayamaz, başkasına gönderemez veya hiçbir şekilde kullanamazsınız. Eğer mesajın yetkili alıcısı veya yetkili alıcısına iletmekten sorumlu kişi siz değilseniz, lütfen mesajı sisteminizden siliniz ve göndereni uyarınız. Gönderen ve ROKETSAN ROKET SANAYİİ VE TİCARET A.Ş. bu mesajın içerdiği bilgilerin doğruluğu, bütünlüğü ve güncelliği konusunda bir garanti vermemektedir. Mesajın içeriğinden, iletilmesinden, alınmasından, saklanmasından, gizliliğinin korunamamasından, virüs içermesinden ve sisteminizde yaratabileceği zararlardan ROKETSAN ROKET SANAYİİ VE TİCARET A.Ş. sorumlu tutulamaz. Şirketimiz hakkında bilgi almak için lütfen web sitemizi ziyaret ediniz. www.roketsan.com.tr<http://www.roketsan.com.tr> This e-mail and its attachments are private and confidential to the exclusive use of the individual or entity to whom it is addressed. It may also be legally confidential. Any disclosure, distribution or other dissemination of this message to any third party is strictly prohibited. If you are not the intended recipient, you may not copy, forward, send or use any part of it. If you are not the intended recipient or the person who is responsible to transmit to the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message and its attachments. The sender and ROKETSAN ROKET SANAYİİ VE TİCARET A.S. do not warrant for the accuracy, currency, integrity or correctness of the information in the message and its attachments. ROKETSAN ROKET SANAYİİ VE TİCARET A.S. shall have no liability with regard to the information contained in the message, its transmission, reception, storage, preservation of confidentiality, viruses or any damages caused in anyway to your computer system. To get information about our company please visit our web site. www.roketsan.com.tr<http://www.roketsan.com.tr>

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pyplusplus generate for strict with char* member
by Dave Wampler Sept. 14, 2013

Sept. 14, 2013

When I try to expose a struct with a char* member, I get a warning that pointer members aren't supported currently. Considering char* is so common in existing APIs, is there a current workaround or example (like conversion to std::string)? Thanks, Dave

1 0

import extension module in python on OSX
by Simon W Sept. 11, 2013

Sept. 11, 2013

Hello, I've compiled the example code for Boost.Python: #include <boost/python.hpp> char const* greet() { return "hello, world"; } BOOST_PYTHON_MODULE(hello_ext) { using namespace boost::python; def("greet", greet); } It compiles and I got an BoostPythonTest.dylib produced by Xcode. I've tried to put that file in my site-packages folder and som other places in order to import it into the interpreter like: import BoostPythonTest Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named 'BoostPythonTest' >>> I've tried to rename it to BoostPythonTest.so and .pyd and so on: But it doesn't work. What is the proper extension name for boost python modules on OSX? I'm using boost 1.53, OSX 1.8 and Python 3.2 Thanks in advance, Simon

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Segfault when passing pointer from C++ to Python via Boost Python
by Alex K Sept. 6, 2013

Sept. 6, 2013

Hello all, I am having issues passing pointers from C++ to python, as I describe here: http://stackoverflow.com/questions/18646694/pass-pointer-from-c-to-python-w… In short, even the example of "Raw C++ pointers" from here: https://wiki.python.org/moin/boost.python/PointersAndSmartPointers causes a segfault when I compile and run it, although I can use other features of Boost Python successfully. The crash appears to be a segfault from invoke.hpp, in this function: template <class RC, class F BOOST_PP_ENUM_TRAILING_PARAMS_Z(1, N, class AC)> inline PyObject* invoke(invoke_tag_<false,false>, RC const& rc, F& f BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(1, N, AC, & ac) ) { return rc(f( BOOST_PP_ENUM_BINARY_PARAMS_Z(1, N, ac, () BOOST_PP_INTERCEPT) )); } Does anyone have any suggestions? Thanks, Alex

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