Error when trying to move the robot via python script

edit

Hello guys, I wrote a little python script to test moving the robot around in Gazebo, in which the robot just rotates around it z axis 5s clockwise and after that 5s counter clockwise in an while loop.

When i started my python script via rosrun move_pepper move_pepper.py i got following error:

pub = rospy.publisher('/pepper/cmd_vel', Twist, queue_size=1) AttributeError: 'module' object has no attribute 'publisher'

I dont really know what this means and i followed a tutorial in which very thing is the same

Here is my script code

#! /usr/bin/env python

import rospy

from geometry_msgs.msg import Twist

from time import sleep

rospy.init_node('movep')

pub = rospy.publisher('/pepper/cmd_vel', Twist, queue_size=1)

rotate_right = True

while not rospy.is_shutdown(): msg = Twist() msg.angular.z = 0.1 if rotate_right else -0.1

pub.publish(msg)

rotate_right = not rotate_right

sleep(5)

what do i need to do to get it running?