Conversely, if the documentation is correct then my ctypes is flawed.

"None, integers, byte strings and unicode strings are the only native 
Python objects that can directly be used as parameters in these function 
calls. None is passed as a C NULL pointer, byte strings and unicode 
strings are passed as pointer to the memory block that contains their 
data (char * or wchar_t *). Python integers are passed as the platforms 
default C int type, their value is masked to fit into the C type."