原标题：如何用Python编写一个聊天室
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：
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
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
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：
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：
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：
5.服务器端完整代码
#!/usr/bin/python# encoding: utf-8from asyncore import dispatcherfrom asynchat import async_chatimport socket, asyncore PORT = 6666 #端口class EndSession(Exception): """ 自定义会话结束时的异常 """ passclass 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 EndSessionclass 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: passclass 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-8import wximport telnetlibfrom time import sleepimport threadclass 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。
