Can anyone please help me, struggling to convert between quaternions and euler angles.

edit

Straight copy of the script:

#!/usr/bin/env python
import rospy
from geometry_msgs.msg import Twist
from geometry_msgs.msg import PoseStamped
from math import sin
from math import cos

twist=Twist()
def callback(data):
    global twist
        twist=data
        print("value of twist cb is:",twist)
def move():
    rospy.init_node('move')
    rospy.Subscriber("cmd_vel",Twist,callback)
    pose_pub=rospy.Publisher("robo_pose",PoseStamped,queue_size=10)
    robo_pose=PoseStamped()

    while not rospy.is_shutdown():

        rate= rospy.Rate(10)
                robo_pose.pose.position.x+=((twist.linear.x*0.1)*cos(robo_pose.pose.orientation.z))+             ((twist.linear.y*0.1)*sin(robo_pose.pose.orientation.z))
        robo_pose.pose.position.y+=((twist.linear.y*0.1)*cos(robo_pose.pose.orientation.z))+((twist.linear.x*0.1)*sin(robo_pose.pose.orientation.z))
        robo_pose.pose.orientation.z+=(twist.angular.z*0.1)
        robo_pose.pose.orientation.normalize()
        robo_pose.header.stamp = rospy.Time.now()
            robo_pose.header.frame_id="map"  
        pose_pub.publish(robo_pose)
        print("pose is:", robo_pose)
        rate.sleep()

if __name__ == '__main__':
    move()