Testing the Hello World tutorial from https://www.boost.org/doc/libs/1_66_0/libs/python/doc/html/tutorial/tutorial/hello.html
Sample program which builds a Hello World module written in C++ and wrapped using using BOOST::PYTHON, as a shared library. Also included is a test python script calling the module.
Makefile assumes Boost libraries are installed and available in path variables.
| Calling C++ functions from python |
| #include <boost/python.hpp> | |
| #include <boost/python/raw_function.hpp> | |
| /* | |
| * C++ project sample to create a class and wrap it using BOOST::PYTHON library | |
| * to be able to interface from python | |
| */ | |
| //Class/Struct to be exposed to python | |
| class Hello{ | |
| private: | |
| std::string msg; | |
| public: | |
| //Hello(std::string msg): msg(msg) {} //overloaded constructor | |
| std::string greet(){ | |
| //std::cout << "Hello World!\n"; | |
| return msg; | |
| } | |
| //Set the message string | |
| void set(std::string text){ | |
| this->msg = text; | |
| } | |
| int len; //public data member | |
| }; | |
| //Raw cpp function | |
| char const* greeter(){ | |
| return "hello World! from outisde class"; | |
| } | |
| namespace python = boost::python; | |
| //Boost.Python wrapper defining the module name, classes and methods | |
| BOOST_PYTHON_MODULE(hello_ext){ | |
| python::class_<Hello>("Hello") | |
| //.def(init<double, double>()) //another constructor if defined | |
| .def("greet",&Hello::greet) | |
| .def("set",&Hello::set) | |
| //.def_readonly("len", &Hello::len) | |
| .def_readwrite("len", &Hello::len) | |
| ; | |
| python::def("greeter", greeter); | |
| } |
| #Makefile to create a shared library of the module | |
| # location of the Python header files | |
| PYTHON_VERSION = 2.7 | |
| PYTHON_INCLUDE = /usr/include/python$(PYTHON_VERSION) | |
| # location of the Boost Python include files and library | |
| BOOST_INC = /usr/include | |
| BOOST_LIB = /usr/lib | |
| # compile mesh classes | |
| TARGET = hello_ext | |
| $(TARGET).so: $(TARGET).o | |
| g++ -shared -Wl,--export-dynamic $(TARGET).o -L$(BOOST_LIB) -lboost_python -L/usr/lib/python$(PYTHON_VERSION)/config -lpython$(PYTHON_VERSION) -o $(TARGET).so | |
| $(TARGET).o: $(TARGET).cpp | |
| g++ -I$(PYTHON_INCLUDE) -I$(BOOST_INC) -fPIC -c $(TARGET).cpp |
| #! /usr/bin/env python | |
| """ | |
| Test script to call the greeter functions and Hello World class obects defined in a CPP module | |
| """ | |
| import hello_ext | |
| print(hello_ext.__dict__) | |
| print(hello_ext.greeter()) | |
| planet = hello_ext.Hello() | |
| print(planet.greet()) | |
| planet.set("howdy") | |
| print(planet.greet()) | |
| planet.set("Hello World!") | |
| print(planet.greet()) |
After attempt of building using
makeI get error:Makefile:11: *** missing separator. stop.