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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 select_where(self, table, cols, pk_att, pk):
        '''
        SELECT with WHERE clause.

            :param table: target table
            :param cols: list of columns to select
            :param pk_att: attribute for the where clause
            :param pk: the id that the pk_att should match
            :return: rows from the given table and cols, with the condition pk_att==pk
            :rtype: list
        '''
        if self.orng_tables:
            data = []
            for ex in self.orng_tables[table]:
                if str(ex[str(pk_att)]) == str(pk):
                    data.append([ex[str(col)] for col in cols])
            return data
        else:
            return self.src.select_where(table, cols, pk_att, pk)