'Assert that a given table exists cannot be selected by name.'

def assertTableDoesNotExist(self, table_name):

    try:
        sqlalchemy.Table(table_name, self.metadata, autoload=True)
    except sqlalchemy.exc.NoSuchTableError:
        pass
    else:
        raise AssertionError(('Table    "%s"    already    exists' % table_name))
