Create new topic that copies odometry topic

edit

Hi all, I want to create a new topic that copies the odometry topic data in order to be able to reset the new topic.

#! /usr/bin/env python
import rospy
from sensor_msgs.msg import LaserScan
from geometry_msgs.msg import Twist
from nav_msgs.msg import Odometry

class reset_odometry:
    def __init__(self):

    rospy.init_node('reset_odometry', anonymous=False)
    self.sub = rospy.Subscriber ('/marvin/diff_drive_controller/odom', Odometry, self.get_odom)
    rospy.sleep(0)
    self.pub = rospy.Publisher('new_pose', Odometry, queue_size=1)
    self.odom = ()
    rospy.spin()
def get_odom (self,msg):
        pose = Odometry()
    self.odom = pose
    print ("pose in callback",self.odom)


def main():
""" main function
"""
node = reset_odometry()

if __name__ == '__main__':
while not rospy.is_shutdown() :
    main()

The way I have written my code the values returned in the new topic are always zero. Any thoughts?