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