举例：使用XML库的方式，实现RPC通信

1、先说结论：使用xml-rpc的机制可以很方便的实现服务器间的RPC调用。

2、试验结果如下：

3、源码如下：

服务器端的源代码如下：

import operator, math
from SimpleXMLRPCServer import SimpleXMLRPCServer
from functools import reduce

def main():
    server = SimpleXMLRPCServer(('127.0.0.1', 7001))
    server.register_introspection_functions()
    server.register_multicall_functions()
    server.register_function(addtogether)
    server.register_function(quadratic)
    server.register_function(remote_repr)

    print("Server ready")
    server.serve_forever()

def addtogether(*things):
    """Add together everything in the list things ."""
    return reduce(operator.add, things)

def quadratic(a, b, c):
    """Determine x values satisfying: a * x * x + b * x + c = 0"""
    b24ac = math.sqrt(b*b - 4.0*a*c)
    return list(set([(-b-b24ac) / 2.0*a, (-b+b24ac) / 2.0*a]))

def remote_repr(arg):
    """return the repr() rendering of the supplied arg """
    return arg

if __name__ == '__main__':
    main()

客户端的代码如下：

import xmlrpclib

def main():
    proxy = xmlrpclib.ServerProxy('http://127.0.0.1:7001')

    print("Here are the functions supported by this server:")

    print("next calculator addtogether: ")
    print(proxy.addtogether('x','y','z'))
    print(proxy.addtogether('x','y','z'))

    print(proxy.addtogether('x','y','z'))
    print(proxy.addtogether('x','y','z'))
    for method_name in proxy.system.listMethods():
        if method_name.startswith('system.'):
            continue

        signatures = proxy.system.methodSignature(method_name)
        if isinstance(signatures, list) and signatures:
            for signature in signatures:
                print('%s(%s)' %(method_name, signature))

        else:
            print('%s(...)' %(method_name,))

        method_help = proxy.system.methodHelp(method_name)
        #if method_help:
        #    print(' ', methodHelp)

    print(proxy.addtogether('x','y','z'))
    print("addtogether result ")

if __name__ == '__main__':
    main()