Mailman 3 May 2014 - 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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np.int64 does not match unsigned long on py3?
by Neal Becker May 29, 2014

May 29, 2014

Using boost::python, it seems a python arg of type np.int64 will match a call requiring c++ type size_t on python2, but on python3 I get: burst.pilot_xsyms = gold_code_generator (-1, -1) (burst.n_pilot_syms) Boost.Python.ArgumentError: Python argument types in gold_code_generator.__call__(gold_code_generator, numpy.int64) did not match C++ signature: __call__(gold_code_generator {lvalue}, unsigned long) __call__(gold_code_generator {lvalue}) Any ideas?

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Boost::Python Reference Counting
by laan May 20, 2014

May 20, 2014

Hi, I'm having issues with Boost::Python objects that contain a reference to a c++ object: --- C++ code ---- #include <boost/python.hpp> struct Container; struct Element { Element(const Container * c) : _container(c) { } std::string name() const; const Container * _container; }; struct Container { Container(const std::string & s) : _string(s) { } Element getElement() { return Element(this); } std::string name() const { return this->_string; } std::string _string; }; std::string Element::name() const { return _container->name(); } using namespace boost::python; BOOST_PYTHON_MODULE(libkatya) { class_<Element>("Element", no_init) .def("name", &Element::name) ; class_<Container>("Container", init<std::string>()) .def("getElement", &Container::getElement) ; } --- Python Code ---------------------- container = test.Container("X") elem = container.getElement() del(container) print(elem.name()) When calling elem.name(), it will reference the "container" object, which has been deleted, and I'm getting a segfault. How can I make boost::python increment the reference counter of Container when an element containing a pointer to the Container is returned? -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Python-Reference-Counting-tp466250… Sent from the Python - c++-sig mailing list archive at Nabble.com.

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LINK : fatal error LNK1181: cannot open input file 'python26_d.lib'
by Florian Maile May 14, 2014

May 14, 2014

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