124     _fieldnames = fieldnames  variable in Struct.CStruct
130     _fieldnames = _fieldnames.split(" ")  variable in Struct.CStruct
166     _offsets = dict(list(zip(_fieldnames, offset_list)))
170     if len(_fieldnames) != numfields:
172                        % (fmt, numfields, fieldnames, len(_fieldnames)))
213         if len(tuple_or_bytes) != len(self._fieldnames):
215                           (self._name, len(self._fieldnames),
216                            ", ".join(self._fieldnames), len(tuple_or_bytes),
222         return self._fieldnames.index(attr)
250               self._fieldnames == other._fieldnames and
284           enumerate(zip(self._fieldnames, self._values))]