Mailman 3 January 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.

4 6

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

4 5

CallPolicy for operators
by Michael Wild March 15, 2013

March 15, 2013

Hi all Is there a way to apply a CallPolicy to operator definitions? In particular, I'm interested in the inplace operators (+=, -=, *=, /= and friends). To give a bit more context: The library I'm trying to wrap exposes some static const objects. So far, I have been able to wrap modifying function by having a registration facility for these static const objects and a custom CallPolicy that raises an AttributError when one tries to modify one of the registered objects. One option I see is to directly define __iadd__ etc. instead of using the built-in convenience operators. However, I'm not sure whether that has unintended side-effects. I haven't completely understood the operators implementation in bp, but it looks fairly involved. Thanks Michael

3 3

Segfault when accessing a boost::python::dict?
by Fred Baba Jan. 30, 2013

Jan. 30, 2013

Hello, I'm a bit new to boost::python and I've run into a strange segmentation fault issue. I'm attempting to convert a dict object to a boost::property_tree::ptree using the code below. I'm getting the error when I attempt to access the input dict, with the following stacktrace: (gdb) bt #0 0x00000001004d58df in PyObject_RichCompare () #1 0x00000001004d64e0 in PyObject_RichCompareBool () #2 0x00000001004cbf9d in lookdict () #3 0x00000001004cfa4f in dict_subscript () #4 0x00000001000c9cc5 in boost::python::api::getitem () #5 0x000000010000218b in boost::python::api::const_item_policies::get (target=@0x7fff5fbff680, key=@0x7fff5fbff688) at object_items.hpp:68 #6 0x000000010000371b in boost::python::api::proxy<boost::python::api::const_item_policies>::operator boost::python::api::object (this=0x7fff5fbff680) at proxy.hpp:64 #7 0x0000000100000f56 in ptree_from_dict (d=@0x7fff5fbff6d0) at test_ptree.cpp:55 #8 0x00000001000015fd in main () at test_ptree.cpp:104 Any help/advice would be greatly appreciated. The code below was adapted from an existing github project, and I can't figure out what's amiss. Thanks, Fred Baba template<typename T> bool try_set(boost::property_tree::ptree &pt, const std::string &key, object &val) { extract<T> ex(val); if (ex.check()) { pt.put<T>(key, ex()); return true; } return false; } boost::property_tree::ptree ptree_from_dict(const dict &d) { boost::property_tree::ptree pt; boost::python::list keys = d.keys(); for (int i = 0; i < len(keys); ++i) { std::string key = extract<std::string>(keys[i]); object val = d[key]; try_set<std::string>(pt, key, val) || try_set<long>(pt, key, val) || try_set<double>(pt, key, val); } return pt; } int main() { try { Py_Initialize(); dict d; d["foo"] = 5; d["bar"] = "baz"; object o = ptree_to_object(ptree()); ptree p = ptree_from_dict(d); write_json(std::cout, p); Py_Finalize(); } catch (error_already_set const&) { PyErr_Print(); } return 0; }

1 0

How to debug pyd File in Visual Studio???
by salinea Jan. 25, 2013

Jan. 25, 2013

Recently, I build a hybrid system with C++ and python. First,I encapsulate a class(I can't guarantee the robustness of this class ) with boost.python which can implement some functions that can not be implemented by C++, I get a .pyd File in result. Second,I embed a python interpreter in c++. Third, use the embed interpreter to execute a .py File.The .py File include the module that in .pyd File I created. Here, the problem comes out! When I start my main project. I can only debug the problems in my main project, when my main project use the python interpreter to execute the python interpreter, I can't see what happened in my pyd File, the whole project collapsed.I know the error is in the pyd File, and if I set a break point in my resource files of pyd File, either the project will go to the break point. Is there any methods to debug the resource file in this condition! -- View this message in context: http://boost.2283326.n4.nabble.com/How-to-debug-pyd-File-in-Visual-Studio-t… Sent from the Python - c++-sig mailing list archive at Nabble.com.

2 1

to_python converter and make_getter
by Michael Wild Jan. 25, 2013

Jan. 25, 2013

Dear all I have defined a to_python converter following http://misspent.wordpress.com/2009/09/27/how-to-write-boost-python-converte…. Everything is fine and dandy, however what bugs me is having to specify a return_value_policy<return_by_value>() for every make_getter call. Looking through the sources it seems that I should be able to tell make_getter what the default policy should be by somehow specializing default_member_getter_policy and default_datum_getter_policy. However, is this the right way to go, or should I attack the problem at a lower level, e.g. by specializing default_getter_by_ref? Or should I directly specialize make_getter? Michael

3 8

Failed to import pyd File When python embed into C++
by salinea Jan. 23, 2013

Jan. 23, 2013

I create a pyd File named "testPyd" with boostPython,and then I import the testPyd module into "test.py", it works perfect! But when I embeded the python interpreter into my C++ project and run the "test.py", it comes out a "ImportErr: no module named testPyd". It has confused me for two days and I googled for long time,but I can't find the answer! Anybody here can help me ? Thank you! Here is my test examples: The C++ codes to build the *pyd File* is: Excute.h #ifndef EXCUTE_H_ #define EXCUTE_H_ #include <string> class Excute { public: Excute(){} int getIoReuslt(std::string ioStr); int getSignal(); }; #endif Excute.cpp: #include "Excute.h" #include "Explanation.h" #include <boost/python.hpp> int Excute::getIoReuslt(std::string ioStr) { return 1; } int Excute::getSignal() { int i = rand()%2; return i; } BOOST_PYTHON_MODULE(pythonDll) { using namespace boost::python; class_<Excute>("Excute", init<>()) .def("getIoResult", &Excute::getIoReuslt) .def("getSignal", &Excute::getSignal) ; } Then a pyd File Named pythonDll is created(pythonDll.pyd), Here are the codes in my test.py: test.py: from pythonDll import* h=Excurte() print h.getIoResult("a") print h.getSignal() And this script works perfect in IDLE. And then I embed python into my C++ project,Here are the test codes: #include <Python.h> #include <string> int main(int argc, char* argv[]) { Py_Initialize(); FILE * fp = fopen("$PATH/test.py", "r"); if (fp == NULL) { return 1; } PyRun_SimpleString("execfile($PATH/test.py')"); Py_Finalize(); system("Pause"); return 0; } The result is: Traceback (most recent call last): File "<string>", line 1, in <module> File "$PATH/test.py", line 1, in <module> from pythonDll import* ImportError: No module named pythonDll [19228 refs] -- View this message in context: http://boost.2283326.n4.nabble.com/Failed-to-import-pyd-File-When-python-em… Sent from the Python - c++-sig mailing list archive at Nabble.com.

3 2

Wrapping a non-copyiable static instance in bp::object
by Michael Wild Jan. 20, 2013

Jan. 20, 2013

Dear all I struggle to find a way in which I can wrap a static instance in a bp::object without copying it. The goal is to have object identity for this static instance: struct A { /*...*/ static A static_a; }; a A::a; bp::object static_instance() { static bp::object* result = new bp::object(A::static_a); // [1] return *result; } Wrapping A and static_instance with Boost.Python is no problem, and everything works as expected, however the A::static_a that is being passed to bp::object() at [1] is being copied, which defeats the whole purpose. Anybody has an idea how achieve this? Thanks! Cheers Michael

2 2

Boost Python quickstart examples error
by Sumeet Jauhar Jan. 8, 2013

Jan. 8, 2013

Hi , when i try running the example under C:\boost_1_50_0\libs\python\ example\quickstart i get the following error and my python file gets removed ( which is quite annoying ) . I am using Python 3.3 & Boost 1.50 on a Windows 7 OS . How do i fix this ? C:\boost_1_50_0\libs\python\example\quickstart>bjam toolset=msvc --verbose-test test > error_log error_log: ...patience... ...patience... ...found 1662 targets... ...updating 11 targets... copy test_extending.py The syntax of the command is incorrect. copy /b + this-file-does-not-exist-A698EE7806899E69 "test_extending.py" "bin\test_ext.test\msvc-10.0\debug\threading-multi\test_extending.py" ...failed copy test_extending.py bin\test_ext.test\msvc-10.0\debug\threading-multi\test_extending.py... ...removing test_extending.py compile-c-c++ bin\msvc-10.0\debug\threading-multi\extending.obj extending.cpp msvc.link.dll bin\msvc-10.0\debug\threading-multi\extending.pyd Creating library bin\msvc-10.0\debug\threading-multi\extending.lib and object bin\msvc-10.0\debug\threading-multi\extending.exp msvc.manifest.dll bin\msvc-10.0\debug\threading-multi\extending.pyd ...skipped <pbin\test_ext.test\msvc-10.0\debug\threading-multi>test_ext for lack of <pbin\test_ext.test\msvc-10.0\debug\threading-multi>test_extending.py... msvc.link bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.exe LINK : warning LNK4001: no object files specified; libraries used LINK : error LNK2001: unresolved external symbol _mainCRTStartup bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.exe : fatal error LNK1120: 1 unresolved externals call "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" x86 >nul link /NOLOGO /INCREMENTAL:NO /DEBUG /MACHINE:X86 /subsystem:console /out:"bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.exe" /LIBPATH:"C:\Python33\libs" @"bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.exe.rsp" if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL% ...failed msvc.link bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.exe bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.pdb... ...removing bin\test_embed.test\msvc-10.0\debug\threading-multi\test_embed.pdb ...skipped <pbin\test_embed.test\msvc-10.0\debug\threading-multi>test_embed.run for lack of <pbin\test_embed.test\msvc-10.0\debug\threading-multi>test_embed.exe... ...failed updating 3 targets... ...skipped 4 targets... ...updated 4 targets...

1 0

compile some code with boost.python by mingw in win7-64bit
by simon zhang Jan. 4, 2013

Jan. 4, 2013

I decided to make my program compatible with windows environment.But I have very little programming experience on windows.There are some errors need help. Environment: - os: win7-64bit, - ide: codeblocks12.11, - python: Python 2.7.3 Windows X86-64 Installer (Windows AMD64 / Intel 64 / X86-64 binary [1] -- does not include source) - compiler: mingw that come from codeblocks installation package. - boost: boost1.52 I only copy and test this "hello" code that come from ".\boost_1_52_0\libs\python\example\tutorial" Code: #include <iostream>#include <boost/python/module.hpp>#include <boost/python/def.hpp> char const* greet(){ return "hello, world"; } BOOST_PYTHON_MODULE(hello_ext){ using namespace boost::python; def("greet", greet);} using namespace std;int main(){ cout << "Hello world!" << endl; return 0;} Error info: mingw32-g++.exe -Wall -fexceptions -g -ID:\boost\include\boost-1_52 -IC:\Python27\include -c E:\project\snail-MW\test1\main.cpp -o obj\Debug\main.o mingw32-g++.exe -LD:\boost\lib\ -LC:\Python27\libs -o bin\Debug\test1.exe obj\Debug\main.o -static obj\Debug\main.o: In function `inithello_ext': E:/project/snail-MW/test1/main.cpp:11: undefined reference to `boost::python::detail::init_module(char const*, void (*)())' obj\Debug\main.o: In function `ZNK5boost6python9type_info4nameEv': D:/boost/include/boost-1_52/boost/python/type_id.hpp:165: undefined reference to `boost::python::detail::gcc_demangle(char const*)' obj\Debug\main.o: In function `ZNK5boost6python15to_python_valueIRKPKcEclES5_': D:/boost/include/boost-1_52/boost/python/converter/builtin_converters.hpp:161: undefined reference to `boost::python::converter::do_return_to_python(char const*)' ................ It have also do some errors that only compile by the command of "bjam toolset=gcc variant=release " in the station ".\boost_1_52_0\libs\python\example\tutorial".

2 2