Dear list, This is my first post here, so I'll briefly introduce myself. My name is Sybren and I'm a PhD student at the Utrecht University. We use Boost a lot in our C++-based framework, and naturally we use Boost::Python to create our Python bindings. I want to combine two "features" that are documented well separately, however so far I haven't been able to combine them. What I want to do is have a class in C++ with virtual methods and override them in a Python subclass, AND have those virtual methods use parameters with default values. In short, I want to wrap a class like this: class ExampleClass { public: virtual std::string override_me(int x, int y=0, bool z=false) { std::stringstream msg; msg << "(x=" << x << ", y=" << y << ", z=" << z << ", base implementation"; return msg.str(); } }; And be able to produce a subclass in Python like this: from cpp_module import ExampleClass class Subclass(ExampleClass): def override_me(self, *args): return ExampleClass.override_me(self, *args) + " has been overridden" Of course all in such a way that when I pass a Subclass instance to an ExampleClass parameter of C++ code, and that C++ code calls instance.override_me(1, 2), it returns "x=1, y=2, z=false, base implementation has been overridden". I can't seem to find any documentation about this, and what I find on this mailing list was posted several years ago and involves manually creating as many methods as there are optional parameters. I hope that in recent versions of Boost (I'm using 1.48 but have no problem upgrading to the latest release) there is a more useful technique. With kind regards, -- Sybren A. Stüvel http://stuvel.eu/