一、课程介绍

1.简介

本次项目课是实现简单聊天室程序的服务器端和客户端。

2.知识点

服务器端涉及到asyncore、asynchat和socket这几个模块，客户端用到了telnetlib、wx、time和thread这几个模块。

3.所需环境

本次课中编写客户端需要用到wxPython，它是一个GUI工具包，请先使用下面的命令安装：

$ sudo apt-get install python-wxtools

密码为shiyanlou

4.项目效果截图

登录窗口

聊天窗口

5.源代码下载

git clone https://github.com/shiyanlou/pythonchat.git

说明：如果你不理解上述代码的下载方式或者下载后在环境中找不到代码，可以点击查看这里

二、项目实战（服务器端）

1.服务器类

首先需要一个聊天服务器，这里继承asyncore的dispatcher类来实现，代码如下

class ChatServer(dispatcher):

    """

    聊天服务器

    """

    def __init__(self, port):

        dispatcher.__init__(self)

        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)

        self.set_reuse_addr()

        self.bind(('', port))

        self.listen(5)

        self.users = {}

        self.main_room = ChatRoom(self)

    def handle_accept(self):

        conn, addr = self.accept()

        ChatSession(self, conn)

2.会话类

有了服务器类还需要能维护每个用户的连接会话，这里继承asynchat的async_chat类来实现，代码如下：

class ChatSession(async_chat):

    """

    负责和单用户通信

    """

    def __init__(self, server, sock):

        async_chat.__init__(self, sock)

        self.server = server

        self.set_terminator('\n')

        self.data = []

        self.name = None

        self.enter(LoginRoom(server))

    def enter(self, room):

        '从当前房间移除自身，然后添加到指定房间'

        try:

            cur = self.room

        except AttributeError:

            pass

        else:

            cur.remove(self)

        self.room = room

        room.add(self)

    def collect_incoming_data(self, data):

        '接受客户端的数据'

        self.data.append(data)

    def found_terminator(self):

        '当客户端的一条数据结束时的处理'

        line = ''.join(self.data)

        self.data = []

        try:

            self.room.handle(self, line)

        except EndSession:

            self.handle_close()

    def handle_close(self):

        async_chat.handle_close(self)

        self.enter(LogoutRoom(self.server))

3.命令解释器

现在就需要一个命令解释器能够解释用户的命令，例如登录、查询在线用户和发消息等，代码如下：

class CommandHandler:

    """

    命令处理类

    """

    def unknown(self, session, cmd):

        '响应未知命令'

        session.push('Unknown command: %s\n' % cmd)

    def handle(self, session, line):

        '命令处理'

        if not line.strip():

            return

        parts = line.split(' ', 1)

        cmd = parts[0]

        try:

            line = parts[1].strip()

        except IndexError:

            line = ''

        meth = getattr(self, 'do_' + cmd, None)

        try:

            meth(session, line)

        except TypeError:

            self.unknown(session, cmd)

4.房间

接下来就需要实现聊天室的房间了，这里我们定义了三种房间，分别是用户刚登录时的房间、聊天的房间和退出登录的房间，这三种房间都有一个公共的父类，代码如下：

class Room(CommandHandler):

    """

    包含多个用户的环境，负责基本的命令处理和广播

    """

    def __init__(self, server):

        self.server = server

        self.sessions = []

    def add(self, session):

        '一个用户进入房间'

        self.sessions.append(session)

    def remove(self, session):

        '一个用户离开房间'

        self.sessions.remove(session)

    def broadcast(self, line):

        '向所有的用户发送指定消息'

        for session in self.sessions:

            session.push(line)

    def do_logout(self, session, line):

        '退出房间'

        raise EndSession

class LoginRoom(Room):

    """

    刚登录的用户的房间

    """

    def add(self, session):

        '用户连接成功的回应'

        Room.add(self, session)

        session.push('Connect Success')

    def do_login(self, session, line):

        '登录命令处理'

        name = line.strip()

        if not name:

            session.push('UserName Empty')

        elif name in self.server.users:

            session.push('UserName Exist')

        else:

            session.name = name

            session.enter(self.server.main_room)

class ChatRoom(Room):

    """

    聊天用的房间

    """

    def add(self, session):

        '广播新用户进入'

        session.push('Login Success')

        self.broadcast(session.name + ' has entered the room.\n')

        self.server.users[session.name] = session

        Room.add(self, session)

    def remove(self, session):

        '广播用户离开'

        Room.remove(self, session)

        self.broadcast(session.name + ' has left the room.\n')

    def do_say(self, session, line):

        '客户端发送消息'

        self.broadcast(session.name + ': ' + line + '\n')

    def do_look(self, session, line):

        '查看在线用户'

        session.push('Online Users:\n')

        for other in self.sessions:

            session.push(other.name + '\n')

class LogoutRoom(Room):

    """

    用户退出时的房间

    """

    def add(self, session):

        '从服务器中移除'

        try:

            del self.server.users[session.name]

        except KeyError:

            pass

5.服务器端完整代码

#!/usr/bin/python

# encoding: utf-8

from asyncore import dispatcher

from asynchat import async_chat

import socket, asyncore

PORT = 6666 #端口

class EndSession(Exception):

    """

    自定义会话结束时的异常

    """

    pass

class CommandHandler:

    """

    命令处理类

    """

    def unknown(self, session, cmd):

        '响应未知命令'

        session.push('Unknown command: %s\n' % cmd)

    def handle(self, session, line):

        '命令处理'

        if not line.strip():

            return

        parts = line.split(' ', 1)

        cmd = parts[0]

        try:

            line = parts[1].strip()

        except IndexError:

            line = ''

        meth = getattr(self, 'do_' + cmd, None)

        try:

            meth(session, line)

        except TypeError:

            self.unknown(session, cmd)

class Room(CommandHandler):

    """

    包含多个用户的环境，负责基本的命令处理和广播

    """

    def __init__(self, server):

        self.server = server

        self.sessions = []

    def add(self, session):

        '一个用户进入房间'

        self.sessions.append(session)

    def remove(self, session):

        '一个用户离开房间'

        self.sessions.remove(session)

    def broadcast(self, line):

        '向所有的用户发送指定消息'

        for session in self.sessions:

            session.push(line)

    def do_logout(self, session, line):

        '退出房间'

        raise EndSession

class LoginRoom(Room):

    """

    刚登录的用户的房间

    """

    def add(self, session):

        '用户连接成功的回应'

        Room.add(self, session)

        session.push('Connect Success')

    def do_login(self, session, line):

        '登录命令处理'

        name = line.strip()

        if not name:

            session.push('UserName Empty')

        elif name in self.server.users:

            session.push('UserName Exist')

        else:

            session.name = name

            session.enter(self.server.main_room)

class ChatRoom(Room):

    """

    聊天用的房间

    """

    def add(self, session):

        '广播新用户进入'

        session.push('Login Success')

        self.broadcast(session.name + ' has entered the room.\n')

        self.server.users[session.name] = session

        Room.add(self, session)

    def remove(self, session):

        '广播用户离开'

        Room.remove(self, session)

        self.broadcast(session.name + ' has left the room.\n')

    def do_say(self, session, line):

        '客户端发送消息'

        self.broadcast(session.name + ': ' + line + '\n')

    def do_look(self, session, line):

        '查看在线用户'

        session.push('Online Users:\n')

        for other in self.sessions:

            session.push(other.name + '\n')

class LogoutRoom(Room):

    """

    用户退出时的房间

    """

    def add(self, session):

        '从服务器中移除'

        try:

            del self.server.users[session.name]

        except KeyError:

            pass

class ChatSession(async_chat):

    """

    负责和单用户通信

    """

    def __init__(self, server, sock):

        async_chat.__init__(self, sock)

        self.server = server

        self.set_terminator('\n')

        self.data = []

        self.name = None

        self.enter(LoginRoom(server))

    def enter(self, room):

        '从当前房间移除自身，然后添加到指定房间'

        try:

            cur = self.room

        except AttributeError:

            pass

        else:

            cur.remove(self)

        self.room = room

        room.add(self)

    def collect_incoming_data(self, data):

        '接受客户端的数据'

        self.data.append(data)

    def found_terminator(self):

        '当客户端的一条数据结束时的处理'

        line = ''.join(self.data)

        self.data = []

        try:

            self.room.handle(self, line)

        except EndSession:

            self.handle_close()

    def handle_close(self):

        async_chat.handle_close(self)

        self.enter(LogoutRoom(self.server))

class ChatServer(dispatcher):

    """

    聊天服务器

    """

    def __init__(self, port):

        dispatcher.__init__(self)

        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)

        self.set_reuse_addr()

        self.bind(('', port))

        self.listen(5)

        self.users = {}

        self.main_room = ChatRoom(self)

    def handle_accept(self):

        conn, addr = self.accept()

        ChatSession(self, conn)

if __name__ == '__main__':

    s = ChatServer(PORT)

    try:

        asyncore.loop()

    except KeyboardInterrupt:

        print

三、项目实战（客户端）

完成了服务器端后，就需要实现客户端了，这里客户端连接服务器使用了telnetlib模块。

1.登录窗口

这里的图形界面包选择了wxPython，前面有安装说明，登录窗口通过继承wx.Frame类来实现，代码如下：

class LoginFrame(wx.Frame):

    """

    登录窗口

    """

    def __init__(self, parent, id, title, size):

        '初始化，添加控件并绑定事件'

        wx.Frame.__init__(self, parent, id, title)

        self.SetSize(size)

        self.Center()

        self.serverAddressLabel = wx.StaticText(self, label = "Server Address", pos = (10, 50), size = (120, 25))

        self.userNameLabel = wx.StaticText(self, label = "UserName", pos = (40, 100), size = (120, 25))

        self.serverAddress = wx.TextCtrl(self, pos = (120, 47), size = (150, 25))

        self.userName = wx.TextCtrl(self, pos = (120, 97), size = (150, 25))

        self.loginButton = wx.Button(self, label = 'Login', pos = (80, 145), size = (130, 30))

        self.loginButton.Bind(wx.EVT_BUTTON, self.login)

        self.Show()

    def login(self, event):

        '登录处理'

        try:

            serverAddress = self.serverAddress.GetLineText(0).split(':')

            con.open(serverAddress[0], port = int(serverAddress[1]), timeout = 10)

            response = con.read_some()

            if response != 'Connect Success':

                self.showDialog('Error', 'Connect Fail!', (95, 20))

                return

            con.write('login ' + str(self.userName.GetLineText(0)) + '\n')

            response = con.read_some()

            if response == 'UserName Empty':

                self.showDialog('Error', 'UserName Empty!', (135, 20))

            elif response == 'UserName Exist':

                self.showDialog('Error', 'UserName Exist!', (135, 20))

            else:

                self.Close()

                ChatFrame(None, -2, title = 'ShiYanLou Chat Client', size = (500, 350))

        except Exception:

            self.showDialog('Error', 'Connect Fail!', (95, 20))

    def showDialog(self, title, content, size):

        '显示错误信息对话框'

        dialog = wx.Dialog(self, title = title, size = size)

        dialog.Center()

        wx.StaticText(dialog, label = content)

        dialog.ShowModal()

2.聊天窗口

聊天窗口中最主要的就是向服务器发消息并接受服务器的消息，这里通过子线程来接受，代码如下：

class ChatFrame(wx.Frame):

    """

    聊天窗口

    """

    def __init__(self, parent, id, title, size):

        '初始化，添加控件并绑定事件'

        wx.Frame.__init__(self, parent, id, title)

        self.SetSize(size)

        self.Center()

        self.chatFrame = wx.TextCtrl(self, pos = (5, 5), size = (490, 310), style = wx.TE_MULTILINE | wx.TE_READONLY)

        self.message = wx.TextCtrl(self, pos = (5, 320), size = (300, 25))

        self.sendButton = wx.Button(self, label = "Send", pos = (310, 320), size = (58, 25))

        self.usersButton = wx.Button(self, label = "Users", pos = (373, 320), size = (58, 25))

        self.closeButton = wx.Button(self, label = "Close", pos = (436, 320), size = (58, 25))

        self.sendButton.Bind(wx.EVT_BUTTON, self.send)

        self.usersButton.Bind(wx.EVT_BUTTON, self.lookUsers)

        self.closeButton.Bind(wx.EVT_BUTTON, self.close)

        thread.start_new_thread(self.receive, ())

        self.Show()

    def send(self, event):

        '发送消息'

        message = str(self.message.GetLineText(0)).strip()

        if message != '':

            con.write('say ' + message + '\n')

            self.message.Clear()

    def lookUsers(self, event):

        '查看当前在线用户'

        con.write('look\n')

    def close(self, event):

        '关闭窗口'

        con.write('logout\n')

        con.close()

        self.Close()

    def receive(self):

        '接受服务器的消息'

        while True:

            sleep(0.6)

            result = con.read_very_eager()

            if result != '':

                self.chatFrame.AppendText(result)

3.客户端完整代码

#!/usr/bin/python

# encoding: utf-8

import wx

import telnetlib

from time import sleep

import thread

class LoginFrame(wx.Frame):

    """

    登录窗口

    """

    def __init__(self, parent, id, title, size):

        '初始化，添加控件并绑定事件'

        wx.Frame.__init__(self, parent, id, title)

        self.SetSize(size)

        self.Center()

        self.serverAddressLabel = wx.StaticText(self, label = "Server Address", pos = (10, 50), size = (120, 25))

        self.userNameLabel = wx.StaticText(self, label = "UserName", pos = (40, 100), size = (120, 25))

        self.serverAddress = wx.TextCtrl(self, pos = (120, 47), size = (150, 25))

        self.userName = wx.TextCtrl(self, pos = (120, 97), size = (150, 25))

        self.loginButton = wx.Button(self, label = 'Login', pos = (80, 145), size = (130, 30))

        self.loginButton.Bind(wx.EVT_BUTTON, self.login)

        self.Show()

    def login(self, event):

        '登录处理'

        try:

            serverAddress = self.serverAddress.GetLineText(0).split(':')

            con.open(serverAddress[0], port = int(serverAddress[1]), timeout = 10)

            response = con.read_some()

            if response != 'Connect Success':

                self.showDialog('Error', 'Connect Fail!', (95, 20))

                return

            con.write('login ' + str(self.userName.GetLineText(0)) + '\n')

            response = con.read_some()

            if response == 'UserName Empty':

                self.showDialog('Error', 'UserName Empty!', (135, 20))

            elif response == 'UserName Exist':

                self.showDialog('Error', 'UserName Exist!', (135, 20))

            else:

                self.Close()

                ChatFrame(None, -2, title = 'ShiYanLou Chat Client', size = (500, 350))

        except Exception:

            self.showDialog('Error', 'Connect Fail!', (95, 20))

    def showDialog(self, title, content, size):

        '显示错误信息对话框'

        dialog = wx.Dialog(self, title = title, size = size)

        dialog.Center()

        wx.StaticText(dialog, label = content)

        dialog.ShowModal()

class ChatFrame(wx.Frame):

    """

    聊天窗口

    """

    def __init__(self, parent, id, title, size):

        '初始化，添加控件并绑定事件'

        wx.Frame.__init__(self, parent, id, title)

        self.SetSize(size)

        self.Center()

        self.chatFrame = wx.TextCtrl(self, pos = (5, 5), size = (490, 310), style = wx.TE_MULTILINE | wx.TE_READONLY)

        self.message = wx.TextCtrl(self, pos = (5, 320), size = (300, 25))

        self.sendButton = wx.Button(self, label = "Send", pos = (310, 320), size = (58, 25))

        self.usersButton = wx.Button(self, label = "Users", pos = (373, 320), size = (58, 25))

        self.closeButton = wx.Button(self, label = "Close", pos = (436, 320), size = (58, 25))

        self.sendButton.Bind(wx.EVT_BUTTON, self.send)

        self.usersButton.Bind(wx.EVT_BUTTON, self.lookUsers)

        self.closeButton.Bind(wx.EVT_BUTTON, self.close)

        thread.start_new_thread(self.receive, ())

        self.Show()

    def send(self, event):

        '发送消息'

        message = str(self.message.GetLineText(0)).strip()

        if message != '':

            con.write('say ' + message + '\n')

            self.message.Clear()

    def lookUsers(self, event):

        '查看当前在线用户'

        con.write('look\n')

    def close(self, event):

        '关闭窗口'

        con.write('logout\n')

        con.close()

        self.Close()

    def receive(self):

        '接受服务器的消息'

        while True:

            sleep(0.6)

            result = con.read_very_eager()

            if result != '':

                self.chatFrame.AppendText(result)

'程序运行'

if __name__ == '__main__':

    app = wx.App()

    con = telnetlib.Telnet()

    LoginFrame(None, -1, title = "Login", size = (280, 200))

    app.MainLoop()

四、小结

最后就可以运行程序进行聊天了，注意需要先启动服务器再启动客户端。这个项目中使用了asyncore的dispatcher来实现服务器，asynchat的asyn_chat来维护用户的连接会话，用wxPython来实现图形界面，用telnetlib来连接服务器，在子线程中接受服务器发来的消息，由此一个简单的聊天室程序就完成了。