How to make use of data from rostopic in robot

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Hello Everyone

I will make this question as clear as possible I have a py program in my PC which gives me coordinates x and y as goalx ang goaly which i am sending to my robot using roslibpy - host and port of the robot.

I can successfully get the data printed in a topic $rostopic echo /chatter as

data "686.75456, 426.85168"
------
data "685.78564, 424.54165"
------
data "684.43565, 422.24769"

I have a small py script in my robot which gets IMU data as well Ideally i want to use the data available in the /chatter to my code in the robot

This is my code is my PC publishing data to the topic /chatter with host 10.0.0.1 the robot

import time
import roslibpy
import localisation.shedrobot_localisation as loc


client = roslibpy.Ros(host='10.0.0.1', port=9090)
client.run()
talker = roslibpy.Topic(client, '/chatter', 'std_msgs/float32')
while client.is_connected:
    loc.tracking_robot()

    goal = str(loc.output)[1:-1]    # loc.output comes from another program which provides me the x and y coordinate
    goalx = str(loc.output[0])[0:-1]
    goaly = str(loc.output[1])[0:-1]

    talker.publish(roslibpy.Message({'data': goal }))      # prints both x and y side by side
    # talker.publish(roslibpy.Message({'data': goalx}))  #prints  x coordinate
    # talker.publish(roslibpy.Message({'data': goaly}))  # prints y coordinate

    print('Sending message to ROBOT from PC...')
    print('x : ',loc.output[0])
    print('y : ',loc.output[1])
    print('ROBOT :',goal)
    time.sleep(0.1)

talker.unadvertise()
client.terminate()

How do i call the goalx and goaly in my py script in my robot, I understand i need to do something like this first?

listener = roslibpy.Topic(client, '/chatter', 'std_msgs/String')

Please let me know Thanks in advance.