Cant't import KafkaClient

[weiboyiyou]

when I use 'from kafka import KafkaClient' ,I got the error 'ImportError: cannot import name KafkaClient'.
but when i use in the python comandline such as: have no import error.
[root@middleware-test bin]# ./python2.7
Python 2.7.12 (default, Sep 30 2016, 15:27:40)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

from kafka import KafkaClient