coscmd -v class YAMLObject(metaclass=YAMLObjectMetaclass): SyntaxError: invalid syntax

[1024ping]

coscmd -v

Traceback (most recent call last): File "/usr/local/bin/coscmd", line 5, in from coscmd.cos_cmd import _main File "/usr/local/lib/python2.7/dist-packages/coscmd/cos_cmd.py", line 18, in from cos_client import CoscmdConfig, CosS3Client File "/usr/local/lib/python2.7/dist-packages/coscmd/cos_client.py", line 18, in import yaml File "/usr/local/lib/python2.7/dist-packages/yaml/init.py", line 362 class YAMLObject(metaclass=YAMLObjectMetaclass): ^ SyntaxError: invalid syntax