Method extract

pandas/io/parsers/base_parser.py:237–238

(r)

            raise ParserError("Header rows must have an equal number of columns.")

        def extract(r):
            return tuple(r[i] for i in range(field_count) if i not in sic)

        columns = list(zip(*(extract(r) for r in header), strict=True))
        names = columns.copy()