Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards


Chapter 1. python 2.0

Joel de Guzman

David Abrahams

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at )

Table of Contents

Building Hello World
Exposing Classes
Class Data Members
Class Properties
Class Virtual Functions
Virtual Functions with Default Implementations
Class Operators/Special Functions
Call Policies
Default Arguments
Object Interface
Basic Interface
Derived Object types
Extracting C++ objects
Creating boost::python::object from PyObject*
Using the interpreter
Exception Translation
General Techniques
Creating Packages
Extending Wrapped Objects in Python
Reducing Compiling Time


The Boost Python Library is a framework for interfacing Python and C++. It allows you to quickly and seamlessly expose C++ classes functions and objects to Python, and vice-versa, using no special tools -- just your C++ compiler. It is designed to wrap C++ interfaces non-intrusively, so that you should not have to change the C++ code at all in order to wrap it, making Boost.Python ideal for exposing 3rd-party libraries to Python. The library's use of advanced metaprogramming techniques simplifies its syntax for users, so that wrapping code takes on the look of a kind of declarative interface definition language (IDL).

Hello World

Following C/C++ tradition, let's start with the "hello, world". A C++ Function:

char const* greet()
   return "hello, world";

can be exposed to Python by writing a Boost.Python wrapper:

#include <boost/python.hpp>

    using namespace boost::python;
    def("greet", greet);

That's it. We're done. We can now build this as a shared library. The resulting DLL is now visible to Python. Here's a sample Python session:

>>> import hello_ext
>>> print hello_ext.greet()
hello, world

Next stop... Building your Hello World module from start to finish...

Last revised: December 26, 2011 at 21:58:39 GMT