Python 3中套接字编程中遇到TypeError: 'str' does not support the buffer interface的解决办法

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 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：

   # 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:

# 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()