Simple python RPC server/client

rpcclient.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: set ts=4 et

import json
import socket

class RpcException(Exception):
    pass

class RpcClient(object):
    def __init__(self, addr):
        self._s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self._s.connect(addr)
        self._input_buf = ''

    def close(self):
        self._s.close()

    def __getattr__(self, name):
        client = self
        self._endpoint = name
        def func(*args):
            d = {'action': 'call', 'endpoint': self._endpoint, 'args': args}
            self._s.send(json.dumps(d) + '\n')
            buf = self._s.recv(16384)
            self._input_buf += buf

            if len(buf) == 0:
                raise RpcException('socket closed')

            line, remainder = self._input_buf.split('\n', 1)
            self._input_buf = remainder

            try:
                response = json.loads(line)
            except:
                raise RpcException('json parse error')

            if not isinstance(response, dict):
                raise RpcException('response is not an instance of dict')

            if not response.has_key('type'):
                raise RpcException('response type missing')

            if response['type'] == u'error':
                if not response.has_key('reason'):
                    raise RpcException('error reponse does not have reason')
                if not isinstance(response['reason'], unicode):
                    raise RpcException('error response reason is not unicode')
                raise RpcException(response['reason'])
            elif response['type'] == u'result':
                if not response.has_key('result'):
                    raise RpcException('result missing')
                return response['result']
        return func

if __name__ == '__main__':
    client = RpcClient(('localhost', 54321))
    print client.greeting()
    name = raw_input('enter a name: ')
    print client.greet_me(name)

rpcserver.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: set ts=4 et

import json
import socket
from select import select

class RpcSession(object):
    def __init__(self, core, s):
        self.core = core
        self.s = s
        self.output_buf = ''
        self.input_buf = ''
        
    def fileno(self):
        return self.s.fileno()
        
    @property
    def can_read(self):
        return True
        
    @property
    def can_write(self):
        return len(self.output_buf) > 0
    
    def do_read(self):
        buf = self.s.recv(16384)
        if len(buf) == 0:
            self.core.selectable.remove(self)
            return
        
        self.input_buf += buf

        while True:
            if not self.input_buf:
                break

            line, remainder = self.input_buf.split('\n', 1)
            self.input_buf = remainder

            try:
                command = json.loads(line)
            except:
                self.error('json parse error')
                continue

            if not isinstance(command, dict):
                self.error('command is not instance of dict')
                continue

            if not command.has_key('action'):
                self.error('no action')
                continue

            if not isinstance(command['action'], unicode):
                self.error('action is not unicode')
                continue

            if command['action'] == u'call':
                if not command.has_key('endpoint'):
                    self.error('no endpoint')
                    continue

                if not isinstance(command['endpoint'], unicode):
                    self.error('endpoint is not unicode')
                    continue

                if not command.has_key('args'):
                    self.error('no args')
                    continue

                if not isinstance(command['args'], list):
                    self.error('args is not list')
                    continue

                self.call(command['endpoint'].decode(), *command['args'])

            else:
                self.error('command is not known')
                continue

    def do_write(self):
        chunk, rest = self.output_buf[:16384], self.output_buf[16384:]
        self.s.send(chunk)
        self.output_buf = rest

    def call(self, name, *args):
        if not self.core.endpoints.has_key(name):
            self.error("endpoint unknown")
            return
        
        endpoint = self.core.endpoints[name]
        if len(args) != endpoint.__code__.co_argcount:
            self.error("endpoint argument count mismatch")
            return

        try:
            result = endpoint(*args)
        except:
            self.error("calling endpoint failed")
            return

        data = {'type': 'result', 'result': result}
        self.output_buf += json.dumps(data) + '\n'

    def error(self, reason):
        data = {'type': 'error', 'reason': reason}
        self.output_buf += json.dumps(data) + '\n'


class RpcServer(object):
    def __init__(self, core, addr):
        self.core = core

        self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.s.bind(addr)
        self.s.listen(5)

    def fileno(self):
        return self.s.fileno()
    
    @property
    def can_read(self):
        return True
        
    @property
    def can_write(self):
        return False

    def do_read(self):
        conn, _ = self.s.accept()
        session = RpcSession(self.core, conn)
        self.core.selectable.append(session)


class RpcCore(object):
    def __init__(self):
        self.selectable = []
        self.endpoints = {}
    
    def listen(self, addr=('0.0.0.0', 54321)):
        listener = RpcServer(self, addr)
        self.selectable.append(listener)

    def run(self):
        self.terminate = False
        while not self.terminate:
            self.tick()
            
    def tick(self):
        read_objs = (obj for obj in self.selectable if obj.can_read)
        write_objs = (obj for obj in self.selectable if obj.can_write)

        readable, writeable, _ = select(read_objs, write_objs, [], 0.25)

        for obj in readable:
            obj.do_read()

        for obj in writeable:
            obj.do_write()

    def shutdown(self, reason=''):
        self.terminate = True

    def export(self, f):
        name = f.__name__
        self.endpoints[name] = f
        return f

if __name__ == '__main__':
    core = RpcCore()
    core.listen(('0.0.0.0', 54321))

    @core.export
    def greeting():
        return 'hello world!'
    
    @core.export
    def greet_me(name):
        return 'hello %s' % name

    core.run()

hi anirey, this is python2 code, it needs conversion