def _ensure_valid_index(self, value):
<EOL>if not len(self.index) and is_list_like(value):<EOL><INDENT>try:<EOL><INDENT>value = Series(value)<EOL><DEDENT>except (ValueError, NotImplementedError, TypeError):<EOL><INDENT>raise ValueError('<STR_LIT>'<EOL>'<STR_LIT>'<EOL>'<STR_LIT>')<EOL><DEDENT>self._data = self._data.reindex_axis(value.index.copy(), axis=<NUM_LIT:1>,<EOL>fill_value=np.nan)<EOL><DEDENT>
Ensure that if we don't have an index, that we can create one from the
passed value.