很多时候需要给c++程序提供一种使用上的灵活性,脚本语言在这里就变得很重要了。采用Boost.Python为c++程序加一层shell,比较简单、简洁,对原有的c++代码也没有侵入性。今天试了一下,感觉不错,可以把它集成在现在正在做的项目中。
我主要参照David Abrahams的"Building Hybrid Systems with Boost.Python"(http://www.boost-consulting.com/writing/bpl.html)一文,该文中对编译过程说的较少,偶就略做补充,为新手节省点时间(偶也是python新手)。
为c++类加python shell过程基本上如下:
(1)为c++类编写一个Boost.Python wrapper
(2)编译成so
(3)可以在python中调用了
针对David Abrahams的例子,偶的源文件如下:
例1:hello world 函数
(1)hello.cpp
- #include <stdexcept>
- char const* greet(unsigned x)
- {
- static char const* const msgs[] = { "hello", "Boost.Python", "world!" };
-
- if (x > 2)
- throw std::range_error("greet: index out of range");
-
- return msgs[x];
- }
(2)hello_wrap.cpp
- #include <boost/python.hpp>
-
- using namespace boost::python;
-
- char const* greet(unsigned x);
-
- BOOST_PYTHON_MODULE(hello)
- {
- def("greet", greet, "return one of 3 parts of a greeting");
- }
(3)makefile
- PYTHON_INCLUDE_FLAGS = \
- -I/usr/include/python2.4
-
- LIB_FLAGS = \
- -lboost_python
-
- SOURCE = \
- hello.cpp hello_wrap.cpp
-
- all:${SOURCE}
- g++ ${PYTHON_INCLUDE_FLAGS} ${SOURCE} ${LIB_FLAGS} -shared -o hello.so
- clean:
- rm -f hello *.o *.out *.so
(4)hello.py
- import hello
- for x in range(3):
- print hello.greet(x)
例2:hello world类
(1)hello_class.cpp
- #include <boost/python.hpp>
- #include <iostream>
- using namespace std;
- using namespace boost::python;
-
- class World
- {
- public:
-
- void set(std::string msg) { this->msg = msg; }
-
- void greet()
- {
- cout << this->msg << endl;
- }
-
- string msg;
- };
-
- BOOST_PYTHON_MODULE(hello)
- {
- class_<World> w("World");
- w.def("greet", &World::greet);
- w.def("set", &World::set);
- };
(2)makefile
PYTHON_INCLUDE_FLAGS = \
-I/usr/include/python2.4
LIB_FLAGS = \
-lboost_python
SOURCE = \
hello_class.cpp
all:${SOURCE}
g++ ${PYTHON_INCLUDE_FLAGS} ${SOURCE} ${LIB_FLAGS} -shared -o hello.so
clean:
rm -f hello *.o *.out *.so
(3)hello_class.py
- import hello
- planet = hello.World()
- planet.set('howdy')
- planet.greet()
更复杂的调用见上面提到的David Abrahams的文章。http://www.cnblogs.com/xiaotie/archive/2006/02/22/335633.html
(David Abrahams) |