code: def get_usage_string(self):
          
          if self.string_index:
              usage_string_type = c_wchar * MAX_HID_STRING_LENGTH
              # 128 max string length
              abuffer = usage_string_type()
              hid_dll.HidD_GetIndexedString(
                  self.hid_report.get_hid_object().hid_handle,
                  self.string_index,
                  byref(abuffer), MAX_HID_STRING_LENGTH-1 )
              return abuffer.value
          return ""
docs: Returns usage representation string (as embedded in HID device
          if available)