TypeError:’str’ does not support the buffer interface

目前正在学习python，使用的工具为python3.2.3。发现3x版本和2x版本有些差异，在套接字编程时，困扰了我很久，先将python核心编程书中的例子
代码如下:
服务器端:
[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片

Echo server program

from socket import *  from time import ctime  HOST = ''                 # Symbolic name meaning all available interfaces  PORT = 50007              # Arbitrary non-privileged port  BUFSIZE = 1024  ADDR = (HOST, PORT)  tcpSerSock = socket(AF_INET, SOCK_STREAM)  tcpSerSock.bind(ADDR)  tcpSerSock.listen(5)  while True:      print('waiting for connection...')      tcpCliSock, addr = tcpSerSock.accept()      print('...connected from:', addr)      while True:          data = tcpCliSock.recv(BUFSIZE)          if not data:              break          tcpCliSock.send(('[%s] %s' % (ctime(), data)))          tcpCliSock.close()  tcpSerSock.close()  

客户端

[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片

Echo client program

from socket import*  HOST = '127.0.0.1'  PORT = 50007              # The same port as used by the server  BUFSIZE = 1024  ADDR = (HOST, PORT)  tcpCliSock = socket(AF_INET, SOCK_STREAM)  tcpCliSock.connect(ADDR)  while True:      data = input('> ')      if not data:          break      tcpCliSock.send(data)      data = tcpCliSock.recv(BUFSIZE)      if not data:          break      print(data)  tcpCliSock.close()  

报错：
TypeError:’str’ does not support the buffer interface
找问题找了好久，在StackOverflow上发现有人也出现同样的问题，并一个叫Scharron的人提出了解答：
In python 3, bytes strings and unicodestrings are now two different types. Since sockets are not aware of string encodings, they are using raw bytes strings, that have a slightly differentinterface from unicode strings.
So, now, whenever you have a unicode stringthat you need to use as a byte string, you need toencode() it. And whenyou have a byte string, you need to decode it to use it as a regular(python 2.x) string.
Unicode strings are quotes enclosedstrings. Bytes strings are b”” enclosed strings

When you use client_socket.send(data),replace it by client_socket.send(data.encode()). When you get datausing data = client_socket.recv(512), replace it by data =client_socket.recv(512).decode()

同时我看了一下python帮助文档：
Codec.encode(input[, errors])
Encodes the object input and returns atuple (output object, length consumed). Encoding converts a string object to abytes object using a particular character set encoding

Codec.decode(input[, errors])
Decodes the object input and returns atuple (output object, length consumed). Decoding converts a bytes objectencoded using a particular character set encoding to a string object.
input must be a bytes object or one whichprovides the read-only character buffer interface – for example, buffer objectsand memory mapped files.

套接字的成员函数send
socket.send(bytes[, flags]) 形参为字节类型
socket.recv(bufsize[, flags]) Receive datafrom the socket. The return value is abytes object representing the data received.
所以修正后代码如下：
服务器端：
[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片

Echo server program

from socket import *  from time import ctime  HOST = ''                 # Symbolic name meaning all available interfaces  PORT = 50007              # Arbitrary non-privileged port  BUFSIZE = 1024  ADDR = (HOST, PORT)  tcpSerSock = socket(AF_INET, SOCK_STREAM)  tcpSerSock.bind(ADDR)  tcpSerSock.listen(5)  while True:      print('waiting for connection...')      tcpCliSock, addr = tcpSerSock.accept()      print('...connected from:', addr)      while True:          data = tcpCliSock.recv(BUFSIZE).decode()          if not data:              break          tcpCliSock.send(('[%s] %s' % (ctime(), data)).encode())          tcpCliSock.close()  tcpSerSock.close()  

客服端
[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片

Echo client program

from socket import*  HOST = '127.0.0.1'  PORT = 50007              # The same port as used by the server  BUFSIZE = 1024  ADDR = (HOST, PORT)  tcpCliSock = socket(AF_INET, SOCK_STREAM)  tcpCliSock.connect(ADDR)  while True:      data = input('> ')      if not data:          break      tcpCliSock.send(data.encode())      data = tcpCliSock.recv(BUFSIZE).decode()      if not data:          break      print(data)  tcpCliSock.close()  

运行结果: 达到预期
在使用这些函数时想当然去用，没有去查找帮助文档，没有弄清楚传参类型，可能是一个例题，没有注意这些，但是得吸取教训。
同样的在udp的情况下：修正过的
服务器端:
[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片

from socket import *  from time import ctime  HOST = '';  PORT = 21546  BUFSIZE = 1024  ADDR = (HOST, PORT)  udpSerSock = socket(AF_INET, SOCK_DGRAM)  udpSerSock.bind(ADDR)  while True:      print('waiting for message...')      data, addr = udpSerSock.recvfrom(BUFSIZE)      udpSerSock.sendto(('[%s] %s' %(ctime(), data.decode())).encode(), addr)      print('...received from and returned to:', addr)  udpSerSock.close()  客户端:[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片from socket import *  HOST = 'localhost'  PORT = 21567  BUFSIZE = 1024  ADDR = (HOST, PORT)  while True:      tcpCliSock = socket(AF_INET, SOCK_STREAM)      tcpCliSock.connect(ADDR)      data = input('> ')      if not data:          break      tcpCliSock.send(('%s\r\n' % data).encode())      data = tcpCliSock.recv(BUFSIZE).decode()      if not data:          break      print(data.strip())  tcpCliSock.close()  使用socketserver模块:服务器端：[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片#TsTservss.py  from socketserver import TCPServer as TCP, StreamRequestHandler as SRH  from time import ctime  HOST = ''  PORT = 21567  ADDR = (HOST, PORT)  class MyRequestHandler(SRH):      def handle(self):          print('...connected from:', self.client_address)          self.wfile.write(('[%s] %s' %(ctime(), self.rfile.readline().decode())).encode())  tcpServ = TCP(ADDR, MyRequestHandler)  print('waiting for connection...')  tcpServ.serve_forever()  客户端：[python] view plaincopyprint?在CODE上查看代码片派生到我的代码片from socket import *  HOST = 'localhost'  PORT = 21567  BUFSIZE = 1024  ADDR = (HOST, PORT)  while True:      tcpCliSock = socket(AF_INET, SOCK_STREAM)      tcpCliSock.connect(ADDR)      data = input('> ')      if not data:          break      tcpCliSock.send(('%s\r\n' % data).encode())      data = tcpCliSock.recv(BUFSIZE).decode()      if not data:          break      print(data.strip())  tcpCliSock.close()