advanced_publish.py

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#!/usr/bin/env python
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# Revision $Id: talker.py 4223 2009-04-16 21:47:54Z jfaustwg $

## talker demo that published std_msgs/ColorRGBA messages
## to the 'color' topic. To see these messages, type:
##   rostopic echo color
## this demo shows some of the more advanced APIs in rospy.

import rospy
from std_msgs.msg import ColorRGBA

def talker():
    topic = 'color'
    pub = rospy.Publisher(topic, ColorRGBA, queue_size=10)
    rospy.init_node('color_talker', anonymous=True)
    print "\n\nNode running. To see messages, please type\n\t'rostopic echo %s'\nIn another window\n\n"%(rospy.resolve_name(topic))
    while not rospy.is_shutdown():

        # publish with in-order initialization of arguments (r, g, b, a)
        pub.publish(1, 2, 3, 4)
        rospy.sleep(.5)

        # publish with a=1, use default values for rest
        pub.publish(a=1.0)
        rospy.sleep(.5)

        # print the number of subscribers
        rospy.loginfo("I have %s subscribers"%pub.get_num_connections())
        
if __name__ == '__main__':
    try:
        talker()
    except rospy.ROSInterruptException: pass