如何将提升模块从C++导入到python

以下是我要导入的c ++代码。

#include <boost/python.hpp>
#include <string>
/*
 * This is the C++ function we write and want to expose to Python.
 */
const std::string hello() {
    return std::string("hello, zoo");
}
/*
 * This is a macro Boost.Python provides to signify a Python extension module.
 */
BOOST_PYTHON_MODULE(zoo) {
    // An established convention for using boost.python.
    using namespace boost::python;
    // Expose the function hello().
    def("hello", hello);
}

以下代码是 python 脚本。

import zoo     # In zoo.cpp we expose hello() function, and it now exists 
                  in the zoo module.
assert 'hello' in dir(zoo)   # zoo.hello is a callable.
assert callable(zoo.hello)   # Call the C++ hello() function from Python.
print zoo.hello()

当我尝试运行脚本时，我在终端上没有收到"你好，动物园"作为输出。我哪里犯了错误？

以下是我收到的错误消息：

导入：未授权zoo' @ error/constitute.c/WriteImage/1028. ./visit_zoo.py: line 3: syntax error near unexpected token （'./visit_zoo.py：第 3 行："在 dir（zoo）中断言'hello'"