def dir_list(self, saltenv='base', prefix=''):
        '''
        List the dirs in the file_roots
        with optional relative prefix path to limit directory traversal
        '''
        ret = []
        if self.opts['file_roots'] not in saltenv:
            return ret
        prefix = prefix.strip('/')
        for path in self.opts['file_roots'][saltenv]:
            for root, dirs, files in os.walk(
                os.path.join(path, prefix), followlinks=True
            ):
                ret.append(sdecode(os.path.relpath(root, path)))
        return ret
dataset/ETHPy150Open saltstack/salt/salt/fileclient.py/LocalClient.dir_list/swapped operands of `not in`