PyArg_Parse*("Z#") raises an error for unknown type instead of ignoring the error and leave the pointer to the string and the size unchanged (not initialized). Fix also the type in the error message of "Z", "Z#" and "Y" formats.

#include "Python.h"

#ifndef PLATFORM
#define PLATFORM "unknown"
#endif

const char *
Py_GetPlatform(void)
{
	return PLATFORM;
}