Socket 是任何一种计算机网络通讯中最基础的内容。当你在浏览器地址栏中输入一个地址时,你会打开一个套接字,可以说任何网络通讯都是通过 Socket 来完成的。
socket和file的区别:
1、file模块是针对某个指定文件进行【打开】【读写】【关闭】
2、socket模块是针对 服务器端 和 客户端Socket 进行【打开】【读写】【关闭】
基本流程:
简单的一个端对端单线通信代码如下:
Server:
1 # -*- coding:utf-8
2 import socket
3 sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
4 sock.bind(("0.0.0.0",12800))
5 sock.listen(2)
6 while True:
7 conn,sockname = sock.accept()
8 print("Now,We have accepted a connection from:",sockname)
9 print("Socket Name is:",conn.getsockname())
10 print("Socket Peer is:",conn.getpeername())
11 message = conn.recv(1024)
12 print("The message we have received is:\n%s"%message)
Client:
# -*- coding:utf-8
import socket
sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
sock.connect(("127.0.0.1",12800))
sock.send(b"Hello World!")
参数解释:
socket.socket(family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None): 创建一个套接字对象,所有套接字操作基于此对象进行
family:套接字协议族,包括:有两种类型的套接字:基于文件的和面向网络的。AF表示地址家族(address family)
AF_UNIX:该套接字是基于文件的,一般用于本机通信
AF_INET:该套接字是基于网络的,这也是最常用的(默认)
AF_INET6 :用于第6 版因特网协议(IPv6)寻址
type:套接字类型,常用的有两种:
SOCK_STREAM:流式socket , for TCP (默认)
SOCK_DGRAM:数据报式socket , for UDP
SOCK_RAW :原始套接字,普通的套接字无法处理ICMP、IGMP等网络报文,而SOCK_RAW可以;其次,SOCK_RAW也可以处理特殊的IPv4报文;此外,利用原始套接字,可以通过IP_HDRINCL套接字选项由用户构造IP头。
SOCK_RDM :是一种可靠的UDP形式,即保证交付数据报但不保证顺序。SOCK_RAM用来提供对原始协议的低级访问,在需要执行某些特殊操作时使用,如发送ICMP报文。SOCK_RAM通常仅限于高级用户或管理员运行的程序使用。
SOCK_SEQPACKET: 可靠的连续数据包服务
proto:协议,与特定的地址家族相关的协议,如果是 0 ,则系统就会根据地址格式和套接类别,自动选择一个合适的协议
sock.bind(address)
sock.bind(address) 将套接字绑定到地址。address地址的格式取决于地址族。在AF_INET下,以元组(host,port)的形式表示地址。
sock.listen(backlog)-- 服务端
开始监听传入连接。backlog指定在拒绝连接之前,可以挂起的最大连接数量。
backlog等于5,表示内核已经接到了连接请求,但服务器还没有调用accept进行处理的连接个数最大为5
这个值不能无限大,因为要在内核中维护连接队列,一般默认值为5
sock.settimeout(timeout)
设置套接字操作的超时期,timeout是一个浮点数,单位是秒。值为None表示没有超时期。一般,超时期应该在刚创建套接字时设置,因为它们可能用于连接的操作(如 client 连接最多等待5s )
sock.getpeername()
返回连接套接字的远程地址。返回值通常是元组(ipaddr,port)。
sock.getsockname()
返回套接字自己的地址。通常是一个元组(ipaddr,port)
sock.fileno()
套接字的文件描述符
sock.setblocking(bool)
是否阻塞(默认True),如果设置False,那么accept和recv时一旦无数据,则报错。
sock.accept()-- 服务端
接受连接并返回(conn,address),其中conn是新的套接字对象,可以用来接收和发送数据。address是连接客户端的地址。
接收TCP 客户的连接(阻塞式)等待连接的到来
sock.connect(address)-- 客户端
连接到address处的套接字。一般,address的格式为元组(hostname,port),如果连接出错,返回socket.error错误。
sock.connect_ex(address)
同上,只不过会有返回值,连接成功时返回 0 ,连接失败时候返回编码,例如:10061
sock.close()
关闭套接字
sock.recv(bufsize[,flag])
接受套接字的数据。数据以字符串形式返回,bufsize指定最多可以接收的数量。flag提供有关消息的其他信息,通常可以忽略。
sock.recvfrom(bufsize[.flag])
与recv()类似,但返回值是(data,address)。其中data是包含接收数据的字符串,address是发送数据的套接字地址。
sock.send(string[,flag])
将string中的数据发送到连接的套接字。返回值是要发送的字节数量,该数量可能小于string的字节大小。即:可能未将指定内容全部发送。
sock.sendall(string[,flag])
将string中的数据发送到连接的套接字,但在返回之前会尝试发送所有数据。成功返回None,失败则抛出异常。
内部通过递归调用send,将所有内容发送出去。
sock.sendto(string[,flag],address)
将数据发送到套接字,address是形式为(ipaddr,port)的元组,指定远程地址。返回值是发送的字节数。该函数主要用于UDP协议。
SocketType.__doc__
1 class SocketType(__builtin__.object)
2 | socket([family[, type[, proto]]]) -> socket object
3 |
4 | Open a socket of the given type. The family argument specifies the
5 | address family; it defaults to AF_INET. The type argument specifies
6 | whether this is a stream (SOCK_STREAM, this is the default)
7 | or datagram (SOCK_DGRAM) socket. The protocol argument defaults to 0,
8 | specifying the default protocol. Keyword arguments are accepted.
9 |
10 | A socket object represents one endpoint of a network connection.
11 |
12 | Methods of socket objects (keyword arguments not allowed):
13 |
14 | accept() -- accept a connection, returning new socket and client address
15 | bind(addr) -- bind the socket to a local address
16 | close() -- close the socket
17 | connect(addr) -- connect the socket to a remote address
18 | connect_ex(addr) -- connect, return an error code instead of an exception
19 | dup() -- return a new socket object identical to the current one [*]
20 | fileno() -- return underlying file descriptor
21 | getpeername() -- return remote address [*]
22 | getsockname() -- return local address
23 | getsockopt(level, optname[, buflen]) -- get socket options
24 | gettimeout() -- return timeout or None
25 | listen(n) -- start listening for incoming connections
26 | makefile([mode, [bufsize]]) -- return a file object for the socket [*]
27 | recv(buflen[, flags]) -- receive data
28 | recv_into(buffer[, nbytes[, flags]]) -- receive data (into a buffer)
29 | recvfrom(buflen[, flags]) -- receive data and sender's address
30 | recvfrom_into(buffer[, nbytes, [, flags])
31 | -- receive data and sender's address (into a buffer)
32 | sendall(data[, flags]) -- send all data
33 | send(data[, flags]) -- send data, may not send all of it
34 | sendto(data[, flags], addr) -- send data to a given address
35 | setblocking(0 | 1) -- set or clear the blocking I/O flag
36 | setsockopt(level, optname, value) -- set socket options
37 | settimeout(None | float) -- set or clear the timeout
38 | shutdown(how) -- shut down traffic in one or both directions
39 |
40 | [*] not available on all platforms!
41 |
42 | Methods defined here:
43
44 |
45 | accept(self)
46 | accept() -> (socket object, address info)
47 |
48 | Wait for an incoming connection. Return a new socket representing the
49 | connection, and the address of the client. For IP sockets, the address
50 | info is a pair (hostaddr, port).
51 |
52 | bind(self, address)
53
54 | bind(address)
55 |
56 | Bind the socket to a local address. For IP sockets, the address is a
57 | pair (host, port); the host must refer to the local host. For raw packet
58 | sockets the address is a tuple (ifname, proto [,pkttype [,hatype]])
59 |
60 | close(self)
61 | close()
62 |
63 | Close the socket. It cannot be used after this call.
64 |
65 | connect(self, address)
66 | connect(address)
67 |
68 | Connect the socket to a remote address. For IP sockets, the address
69 | is a pair (host, port).
70 |
71 | connect_ex(self, address)
72 | connect_ex(address) -> errno
73 |
74 | This is like connect(address), but returns an error code (the errno value)
75 | instead of raising an exception when an error occurs.
76 |
77 | fileno(self)
78 | fileno() -> integer
79 |
80 | Return the integer file descriptor of the socket.
81 |
82 | getpeername(self)
83 | getpeername() -> address info
84 |
85 | Return the address of the remote endpoint. For IP sockets, the address
86 | info is a pair (hostaddr, port).
87 |
88 | getsockname(self)
89 | getsockname() -> address info
90 |
91 | Return the address of the local endpoint. For IP sockets, the address
92 | info is a pair (hostaddr, port).
93 |
94 | getsockopt(self, level, option, buffersize=None)
95 | getsockopt(level, option[, buffersize]) -> value
96 |
97 | Get a socket option. See the Unix manual for level and option.
98 | If a nonzero buffersize argument is given, the return value is a
99 | string of that length; otherwise it is an integer.
100 |
101 | gettimeout(self)
102 | gettimeout() -> timeout
103 |
104 | Returns the timeout in seconds (float) associated with socket
105 | operations. A timeout of None indicates that timeouts on socket
106 | operations are disabled.
107 |
108 | ioctl(self, cmd, option)
109 | ioctl(cmd, option) -> long
110 |
111 | Control the socket with WSAIoctl syscall. Currently supported 'cmd' values are
112 | SIO_RCVALL: 'option' must be one of the socket.RCVALL_* constants.
113 | SIO_KEEPALIVE_VALS: 'option' is a tuple of (onoff, timeout, interval).
114 |
115 | listen(self, backlog)
116 | listen(backlog)
117 |
118 | Enable a server to accept connections. The backlog argument must be at
119 | least 0 (if it is lower, it is set to 0); it specifies the number of
120 | unaccepted connections that the system will allow before refusing new
121 | connections.
122 |
123 | recv(self, buffersize, flags=None)
124 | recv(buffersize[, flags]) -> data
125 |
126 | Receive up to buffersize bytes from the socket. For the optional flags
127 | argument, see the Unix manual. When no data is available, block until
128 | at least one byte is available or until the remote end is closed. When
129 | the remote end is closed and all data is read, return the empty string.
130 |
131 | recv_into(self, buffer, nbytes=None, flags=None)
132 | recv_into(buffer, [nbytes[, flags]]) -> nbytes_read
133 |
134 | A version of recv() that stores its data into a buffer rather than creating
135 | a new string. Receive up to buffersize bytes from the socket. If buffersize
136 | is not specified (or 0), receive up to the size available in the given buffer.
137 |
138 | See recv() for documentation about the flags.
139 |
140 | recvfrom(self, buffersize, flags=None)
141 | recvfrom(buffersize[, flags]) -> (data, address info)
142 |
143 | Like recv(buffersize, flags) but also return the sender's address info.
144 |
145 | recvfrom_into(self, buffer, nbytes=None, flags=None)
146 | recvfrom_into(buffer[, nbytes[, flags]]) -> (nbytes, address info)
147 |
148 | Like recv_into(buffer[, nbytes[, flags]]) but also return the sender's address info.
149 |
150 | send(self, data, flags=None)
151 | send(data[, flags]) -> count
152 |
153 | Send a data string to the socket. For the optional flags
154 | argument, see the Unix manual. Return the number of bytes
155 | sent; this may be less than len(data) if the network is busy.
156 |
157 | sendall(self, data, flags=None)
158 | sendall(data[, flags])
159 |
160 | Send a data string to the socket. For the optional flags
161 | argument, see the Unix manual. This calls send() repeatedly
162 | until all data is sent. If an error occurs, it's impossible
163 | to tell how much data has been sent.
164 |
165 | sendto(self, data, flags=None, *args, **kwargs)
166 | sendto(data[, flags], address) -> count
167 |
168 | Like send(data, flags) but allows specifying the destination address.
169 | For IP sockets, the address is a pair (hostaddr, port).
170 |
171 | setblocking(self, flag)
172 | setblocking(flag)
173 |
174 | Set the socket to blocking (flag is true) or non-blocking (false).
175 | setblocking(True) is equivalent to settimeout(None);
176 | setblocking(False) is equivalent to settimeout(0.0).
177 |
178 | setsockopt(self, level, option, value)
179 | setsockopt(level, option, value)
180 |
181 | Set a socket option. See the Unix manual for level and option.
182 | The value argument can either be an integer or a string.
183 |
184 | settimeout(self, timeout)
185 | settimeout(timeout)
186 |
187 | Set a timeout on socket operations. 'timeout' can be a float,
188 | giving in seconds, or None. Setting a timeout of None disables
189 | the timeout feature and is equivalent to setblocking(1).
190 | Setting a timeout of zero is the same as setblocking(0).
191 |
192 | shutdown(self, flag)
193 | shutdown(flag)
194 |
195 | Shut down the reading side of the socket (flag == SHUT_RD), the writing side
196 | of the socket (flag == SHUT_WR), or both ends (flag == SHUT_RDWR).
197
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