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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def isempty(self, tables=None):
 """ Return whether a table or the entire database is empty. A database is empty is if it has no tables. A table is empty if it has no rows. Arguments: tables (sequence of str, optional):
 If provided, check that the named tables are empty. If not provided, check that all tables are empty. Returns: bool: True if tables are empty, else false. Raises: sql.OperationalError: If one or more of the tables do not exist. """

        tables = tables or self.tables

        for table in tables:
            if self.num_rows(table) > 0:
                return False

        return True