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// Copyright Stefan Seefeld 2005.
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <boost/python.hpp>
#include <boost/detail/lightweight_test.hpp>
#include <iostream>
namespace python = boost::python;
// An abstract base class
class Base : public boost::noncopyable
{
public:
virtual ~Base() {};
virtual std::string hello() = 0;
};
// C++ derived class
class CppDerived : public Base
{
public:
virtual ~CppDerived() {}
virtual std::string hello() { return "Hello from C++!";}
};
// Familiar Boost.Python wrapper class for Base
struct BaseWrap : Base, python::wrapper<Base>
{
virtual std::string hello()
{
#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
// workaround for VC++ 6.x or 7.0, see
// http://boost.org/libs/python/doc/tutorial/doc/html/python/exposing.html#python.class_virtual_functions
return python::call<std::string>(this->get_override("hello").ptr());
#else
return this->get_override("hello")();
#endif
}
};
// Pack the Base class wrapper into a module
BOOST_PYTHON_MODULE(embedded_hello)
{
python::class_<BaseWrap, boost::noncopyable> base("Base");
}
void eval_test()
{
python::object result = python::eval("'abcdefg'.upper()");
std::string value = python::extract<std::string>(result) BOOST_EXTRACT_WORKAROUND;
BOOST_TEST(value == "ABCDEFG");
}
void exec_test()
{
// Retrieve the main module
python::object main = python::import("__main__");
// Retrieve the main module's namespace
python::object global(main.attr("__dict__"));
// Define the derived class in Python.
python::object result = python::exec(
"from embedded_hello import * \n"
"class PythonDerived(Base): \n"
" def hello(self): \n"
" return 'Hello from Python!' \n",
global, global);
python::object PythonDerived = global["PythonDerived"];
// Creating and using instances of the C++ class is as easy as always.
CppDerived cpp;
BOOST_TEST(cpp.hello() == "Hello from C++!");
// But now creating and using instances of the Python class is almost
// as easy!
python::object py_base = PythonDerived();
Base& py = python::extract<Base&>(py_base) BOOST_EXTRACT_WORKAROUND;
// Make sure the right 'hello' method is called.
BOOST_TEST(py.hello() == "Hello from Python!");
}
void exec_file_test(std::string const &script)
{
// Run a python script in an empty environment.
python::dict global;
python::object result = python::exec_file(script.c_str(), global, global);
// Extract an object the script stored in the global dictionary.
BOOST_TEST(python::extract<int>(global["number"]) == 42);
}
void exec_test_error()
{
// Execute a statement that raises a python exception.
python::dict global;
python::object result = python::exec("print(unknown) \n", global, global);
}
void exercise_embedding_html()
{
using namespace boost::python;
/* code from: libs/python/doc/tutorial/doc/tutorial.qbk
(generates libs/python/doc/tutorial/doc/html/python/embedding.html)
*/
object main_module = import("__main__");
object main_namespace = main_module.attr("__dict__");
object ignored = exec("hello = file('hello.txt', 'w')\n"
"hello.write('Hello world!')\n"
"hello.close()",
main_namespace);
}
void check_pyerr(bool pyerr_expected=false)
{
if (PyErr_Occurred())
{
if (!pyerr_expected) {
BOOST_ERROR("Python Error detected");
PyErr_Print();
}
else {
PyErr_Clear();
}
}
else
{
BOOST_ERROR("A C++ exception was thrown for which "
"there was no exception handler registered.");
}
}
int main(int argc, char **argv)
{
BOOST_TEST(argc == 2 || argc == 3);
std::string script = argv[1];
// Register the module with the interpreter
if (PyImport_AppendInittab(const_cast<char*>("embedded_hello"),
#if PY_VERSION_HEX >= 0x03000000
PyInit_embedded_hello
#else
initembedded_hello
#endif
) == -1)
{
BOOST_ERROR("Failed to add embedded_hello to the interpreter's "
"builtin modules");
}
// Initialize the interpreter
Py_Initialize();
if (python::handle_exception(eval_test)) {
check_pyerr();
}
else if(python::handle_exception(exec_test)) {
check_pyerr();
}
else if (python::handle_exception(boost::bind(exec_file_test, script))) {
check_pyerr();
}
if (python::handle_exception(exec_test_error))
{
check_pyerr(/*pyerr_expected*/ true);
}
else
{
BOOST_ERROR("Python exception expected, but not seen.");
}
if (argc > 2) {
// The main purpose is to test compilation. Since this test generates
// a file and I (rwgk) am uncertain about the side-effects, run it only
// if explicitly requested.
exercise_embedding_html();
}
// Boost.Python doesn't support Py_Finalize yet.
// Py_Finalize();
return boost::report_errors();
}
// Including this file makes sure
// that on Windows, any crashes (e.g. null pointer dereferences) invoke
// the debugger immediately, rather than being translated into structured
// exceptions that can interfere with debugging.
#include "module_tail.cpp"
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