python ros 回充demo

#!/usr/bin/env python
#coding=utf-import rospy
from std_msgs.msg import String
i=
def talker():
global i
pub = rospy.Publisher('nav_goal',String, queue_size=)
rospy.init_node('talker',anonymous=True)
#rate = rospy.Rate() # 10hz
#rospy.signal_shutdown("closed!")
while not rospy.is_shutdown():
rospy.loginfo("pub")
pub.publish(String(data="charging_port"))
i=i+
#rate.sleep()if __name__ == '__main__':
try:
talker()
except rospy.ROSInterruptException:
pass