Return array rank or 0 for scalar.

def get_var_rank(self, name):
        """
        Return array rank or 0 for scalar.
        """
        name = create_string_buffer(name)
        rank = c_int()
        self.library.get_var_rank.argtypes = [c_char_p, POINTER(c_int)]
        self.library.get_var_rank.restype = None
        self.library.get_var_rank(name, byref(rank))
        return rank.value