I am dealing with image buffers, and I want to be able to access data a few lines into my image for analysis with a c library.  I have created my 8-bit pixel buffer in Python using create_string_buffer.  Is there a way to get a pointer to a location within that buffer without re-creating a new buffer?  My goal is to analyze and change data within that buffer in chunks, without having to do a lot of buffer creation and data copying.
In this case, ultimately, the C library is doing all the manipulation of the buffer, so I don't actually have to change values within the buffer using Python.  I just need to give my C function access to data within the buffer.
You can also use ctypes.cast(buf, ctypes.c_void_p)
ctypes and pointer manipulation