python中socket编程遇到TypeError: 'str' does not support the buffer interface

本文转自：http://blog.csdn.net/chuanchuan608/article/details/17915959

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

    # 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：

    # 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 unicode strings are now two different types. Since sockets are not aware of string encodings, they are using raw bytes strings, that have a slightly different interface from unicode strings.

在python3种，字节字符串和unicode字符串已经成为两种类型。由于套接字并不‘认识’字符串编码，所以socket就用最原始的字节字符串进行传输。字节字符串和unicod字符串在接口上有着轻微的不同。

So, now, whenever you have a unicode string that you need to use as a byte string, you need to encode() it. And whenyou have a byte string, you need to decode it to use it as a regular(python 2.x) string.

所以，当你想要将unicode字符串当作字节字符串使用时，就需要对他进行编码。而当接受到字节字符串时，为了正常使用它，就需要对他进行解码

Unicode strings are quotes enclosed strings. 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()

 

当使用socket.send(data)时，不要再这样用了，应该换为socket.send(data.encode())

当使用socket.recv(512)时，应该换为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：

    # 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()  

客户端：

    # 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:

    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：

    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：

    #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：

    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()