关于rospy 中service的理解及例子程序

Server部分：

#！/usr/bin/env python

import sys
import os

import rospy
#from beginner.srv import *
from beginner.srv
import AddTwoInts

def
add_two_ints_client(x,y):
rospy.wait_for_service('add_two_ints')# rospy.wait_for_service（‘service的tipoc’）
try:
add_two_ints=rospy.ServiceProxy('add_two_ints',AddTwoInts)#client请求（request）后server的返回值（response）add_two_ints 通过rospy.ServiceProxy的方式向service发送（request）请求
resp1=add_two_ints(x,y) #将参数发送给server
return resp1.sum
except rospy.ServiceException, e:
print
"Service call failed: %s"%e

def
usage():
return
"%s [x,y]"%sys.argv[0]

if
__name__=="__main__":
if
len(sys.argv)==3:
x=int(sys.argv[1])
y=int(sys.argv[2])
else:
print usage()
sys.exit(1)
print"Resquesting %s+%s"%(x,y)
print"%s+%s=%s"%(x,y,add_two_ints_client(x,y))

Client部分：

import rospy
from beginner.srv
import *
#from beginner.srv import *
#from beginner.srv import AddTwoInts

def
handle_add_two_ints(req):
print("Returning[%s+%s=%s]"%(req.a,req.b,(req.a+req.b)))
sum=req.a+req.b
return AddTwoIntsResponse(sum)

def
add_two_ints_server():
rospy.init_node('add_two_ints_server')
s = rospy.Service('add_two_ints',AddTwoInts,handle_add_two_ints)#服务节点，服务类型，这里必须和AddTwoInts.srv的文件名一致，处理函数 处理函数调用和返回实例化的AddTwoIntsRes
print"Ready to add Two Ints"
rospy.spin()
if
__name__=="__main__":
add_two_ints_server()