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POHow can I extract a wrapped C++ type from a Python type using boost::python?
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13635790
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14486487
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1
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2012-11-29T22:17:32.647
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2013-01-23T18:12:16.670
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2012-11-30T17:02:24.493
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20518
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1
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1
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135
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I've wrapped a C++ class using Py++ and everything is working great in Python. I can instantiate the c++ class, call methods, etc. I'm now trying to embed some Python into a C++ application. This is also working fine for the most-part. I can call functions on a Python module, get return values, etc. The python code I'm calling returns one of the classes that I wrapped: <pre><code>import _myextension as myext def run_script(arg): my_cpp_class = myext.MyClass() return my_cpp_class </code></pre> I'm calling this function from C++ like this: <pre><code>// ... excluding error checking, ref counting, etc. for brevity ... PyObject *pModule, *pFunc, *pArgs, *pReturnValue; Py_Initialize(); pModule = PyImport_Import(PyString_FromString("cpp_interface")); pFunc = PyObject_GetAttrString(pModule, "run_script"); pArgs = PyTuple_New(1); PyTuple_SetItem(pArgs, 0, PyString_FromString("an arg")); pReturnValue = PyObject_CallObject(pFunc, pArgs); bp::extract< MyClass& > extractor(pReturnValue); // PROBLEM IS HERE if (extractor.check()) { // This check is always false MyClass& cls = extractor(); } </code></pre> The problem is the extractor never actually extracts/converts the PyObject* to MyClass (i.e. extractor.check() is always false). According to <a href="http://www.boost.org/doc/libs/1_47_0/libs/python/doc/tutorial/doc/html/python/object.html#python.extracting_c___objects" rel="nofollow">the docs</a> this is the correct way to extract a wrapped C++ class. I've tried returning basic data types (ints/floats/dicts) from the Python function and all of them are extracted properly. Is there something I'm missing? Is there another way to get the data and cast to MyClass?
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<c++><boost-python><py++>
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How can I extract a wrapped C++ type from a Python type using boost::python?
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