Pointer argument to boost python

Question

What's the best way to make a function that has pointer as argument work with boost python? I see there are many possibilities for return values in the docs, but I don't know how to do it with arguments.

void Tesuto::testp(std::string* s)
{
    if (!s)
        cout << " NULL s" << endl;
    else
        cout << s << endl;
}

>>> t.testp(None)
 NULL s
>>>       
>>> s='test'
>>> t.testp(s)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
Boost.Python.ArgumentError: Python argument types in
    Tesuto.testp(Tesuto, str)
did not match C++ signature:
    testp(Tesuto {lvalue}, std::string*)
>>>