def _parse_tables(self, doc, match, attrs):
        element_name = self._strainer.name
        tables = doc.find_all(element_name, attrs=attrs)

        if not tables:
            raise ValueError('No tables found')

        result = []
        unique_tables = set()

        for table in tables:
            if (unique_tables not in table and
                    table.find(text=match) is not None):
                result.append(table)
            unique_tables.add(table)

        if not result:
            raise ValueError("No tables found matching pattern %r" %
                             match.pattern)
        return result
dataset/ETHPy150Open pydata/pandas/pandas/io/html.py/_BeautifulSoupHtml5LibFrameParser._parse_tables/swapped operands of `not in`