" rostopic list " error

edit

rostopic list throws below error message:

 rostopic list
Traceback (most recent call last):
  File "/opt/ros/groovy/bin/rostopic", line 34, in <module>
    import rostopic
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rostopic/__init__.py", line 58, in <module>
    import rospy
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rospy/__init__.py", line 49, in <module>
    from .client import spin, myargv, init_node, \
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rospy/client.py", line 59, in <module>
    import rospy.impl.init
  File "/opt/ros/groovy/lib/python2.7/dist-packages/rospy/impl/init.py", line 107, in <module>
    class RosStreamHandler(rosgraph.roslogging.RosStreamHandler):
AttributeError: 'module' object has no attribute 'RosStreamHandler'

This error comes when I am executing this command on workstation computer. But when I run the same on turtlebot computer, it displays published topics.

Anyone please let me know what could be the issue.