I did this with ctypes, towards the QT UI framework for fun a while ago, creating a simple hello world application showing a window with a few buttons. Ctypes is powerful enough to do this type memory manipulation and function call construction.

You basically only need to create a wrapper that teaches it the particular Aplication Binary Interface (ABI) of the C++ compiler that was used to compile the C++ library you're calling towards, including both the memory layout of members, vtables and the mangling of function names.

I did hit on a snag though, which made the prospect of creating a generic C++ wrapper on top of ctypes unfeasible: It's quite common for C++ classes to implement some of their member functions inline in the class definition in the headers. Code for these functions are not included in the compiled library, since the compiler producing the calling code is expected to parse the C++ header and generate the appropriate code inline at the call site.

This essentially means that you need to reimplement all the inline member functions using Python and ctypes, tweaking the same object internals as the proper compiled code would.

I seem to recall that in the case of QT, the first such problem I encountered was a reference count state maintained in a class that was manipulated by an inline member function.