why message_filters is not working ?

edit

System information OS: Ubuntu 18.04 ROS version: Melodic I am trying to implement message_filters in ROS, python3, melodic. I dont seem to understand why it's not working, no error in console, it stays as it is.

import rospy
import message_filters   
from sensor_msgs.msg import Image, CameraInfo

def callback(image, camera_info):   
          print(image)   
           print("5"*10)
            print(camera_info)


rospy.init_node("nod", anonymous = True)  
image_sub = message_filters.Subscriber('/openmv_cam/image', Image)   
info_sub = message_filters.Subscriber('/openmv_cam/camera_info', CameraInfo)    

ts = message_filters.ApproximateTimeSynchronizer([image_sub, info_sub], 10, 0,2)    
ts.registerCallback(callback)   
rospy.spin()

PS: just copy pasted this from other examples. also used TimeSynchronizer , still no output !! It doesn't throw any error, shows no output !! also tried on machine with just python2, still no output !!

pardon me for writing code like this, no karma points here!!