when using python3.4, error occured:TypeError: the JSON object must be str, not 'bytes'

[zhangjianpinghik]

root@ubuntu:/etc# /usr/local/bin/circusd /etc/circus.ini
2018-01-19 09:23:51 circus[25281] [INFO] Starting master on pid 25281
2018-01-19 09:23:51 circus[25281] [INFO] sockets started
2018-01-19 09:23:51 circus[25281] [INFO] Arbiter now waiting for commands
2018-01-19 09:23:51 circus[25281] [INFO] add_host started
2018-01-19 09:23:51 circus[25281] [INFO] celerybeat started
2018-01-19 09:23:51 circus[25281] [INFO] celeryflower started
2018-01-19 09:23:51 circus[25281] [INFO] create_vm started
2018-01-19 09:23:51 circus[25281] [INFO] other_operate started
2018-01-19 09:23:51 circus[25281] [INFO] schedule_task started
2018-01-19 09:23:51 circus[25281] [INFO] circushttpd started
2018-01-19 09:23:52 circus-web[25296] [INFO] Starting circus web ui on fd 20
2018-01-19 09:23:52 tornado.application[25296] [ERROR] Exception in callback (14, <function wrap..null_wrapper at 0x7f84c2cb5488>)
Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/tornado/ioloop.py", line 888, in start
handler_func(fd_obj, events)
File "/usr/local/lib/python3.4/dist-packages/tornado/stack_context.py", line 277, in null_wrapper
return fn(*args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/circus_web-1.1.0.dev0-py3.4.egg/circusweb/util.py", line 86, in get_message
data = json.loads(data)
File "/usr/lib/python3.4/json/init.py", line 312, in loads
s.class.name))
TypeError: the JSON object must be str, not 'bytes'