Python socket简介

smith88

自豪地使用dir和help.

Python 2.7.2 (default, Jun 20 2012, 16:23:33)
[GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import socket
>>> dir(socket.socket)
['__class__', '__delattr__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__slots__', '__str__', '__subclasshook__', '__weakref__', '_sock', 'accept', 'bind', 'close', 'connect', 'connect_ex', 'dup', 'family', 'fileno', 'getpeername', 'getsockname', 'getsockopt', 'gettimeout', 'listen', 'makefile', 'proto', 'recv', 'recv_into', 'recvfrom', 'recvfrom_into', 'send', 'sendall', 'sendto', 'setblocking', 'setsockopt', 'settimeout', 'shutdown', 'type']
>>> help(socket.socket)
class _socketobject(__builtin__.object)
| socket([family[, type[, proto]]]) -> socket object
|  
| Open a socket of the given type. The family argument specifies the
| address family; it defaults to AF_INET. The type argument specifies
| whether this is a stream (SOCK_STREAM, this is the default)
| or datagram (SOCK_DGRAM) socket. The protocol argument defaults to 0,
| specifying the default protocol. Keyword arguments are accepted.
|  
| A socket object represents one endpoint of a network connection.
|  
| Methods of socket objects (keyword arguments not allowed):
|  
| accept() -- accept a connection, returning new socket and client address
| bind(addr) -- bind the socket to a local address
| close() -- close the socket
| connect(addr) -- connect the socket to a remote address
| connect_ex(addr) -- connect, return an error code instead of an exception
| dup() -- return a new socket object identical to the current one

| fileno() -- return underlying file descriptor
| getpeername() -- return remote address

| getsockname() -- return local address
| getsockopt(level, optname[, buflen]) -- get socket options
| gettimeout() -- return timeout or None
| listen(n) -- start listening for incoming connections
| makefile([mode, [bufsize]]) -- return a file object for the socket

| recv(buflen[, flags]) -- receive data
| recv_into(buffer[, nbytes[, flags]]) -- receive data (into a buffer)
| recvfrom(buflen[, flags]) -- receive data and sender's address
| recvfrom_into(buffer[, nbytes, [, flags])
| -- receive data and sender's address (into a buffer)
| sendall(data[, flags]) -- send all data
| send(data[, flags]) -- send data, may not send all of it
| sendto(data[, flags], addr) -- send data to a given address
| setblocking(0 | 1) -- set or clear the blocking I/O flag
| setsockopt(level, optname, value) -- set socket options
| settimeout(None | float) -- set or clear the timeout
| shutdown(how) -- shut down traffic in one or both directions
>>> help(socket.getaddrinfo)
Help on built-in function getaddrinfo in module _socket:
getaddrinfo(…)
getaddrinfo(host, port [, family, socktype, proto, flags])
-> list of (family, socktype, proto, canonname, sockaddr)
Resolve host and port into addrinfo struct.

Simple Demo:

# Echo server program
import socket
HOST ='' # Symbolic name meaning all available interfaces
PORT =50007 # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print'Connected by', addr
while 1:
data = conn.recv(1024)
if not data: break
conn.sendall(data)
conn.close()


# Echo client program
import socket
HOST ='' # The remote host
PORT =50007 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall('Hello, world')
data = s.recv(1024)
s.close()
print'Received', repr(data)

1、setblocking(0 | 1) -- set or clear the blocking I/O flag
引用
Set blocking or non-blocking mode of the socket: if flag is 0, the socket is set to non-blocking, else to blocking mode. Initially all sockets are in blocking mode. In non-blocking mode, if a recv() call doesn’t find any data, or if a send() call can’t immediately dispose of the data, a error exception is raised; in blocking mode, the calls block until they can proceed. s.setblocking(0) is equivalent to s.settimeout(0.0); s.setblocking(1) is equivalent to s.settimeout(None).

2、setsockopt(level, optname, value) -- set socket options
引用
Set the value of the given socket option (see the Unix manual page setsockopt(2)). The needed symbolic constants are defined in the socket module (SO_* etc.). The value can be an integer or a string representing a buffer. In the latter case it is up to the caller to ensure that the string contains the proper bits (see the optional built-in module struct for a way to encode C structures as strings).

套接字机制提供两个套接字选项接口来控制套接字行为。一个用来设置，一个用来获取。(getsockopt)
3、settimeout(None | float) -- set or clear the timeout
引用
Set a timeout on blocking socket operations. The value argument can be a nonnegative float expressing seconds, or None. If a float is given, subsequent socket operations will raise a timeout exception if the timeout period value has elapsed before the operation has completed. Setting a timeout of None disables timeouts on socket operations. s.settimeout(0.0) is equivalent to s.setblocking(0); s.settimeout(None) is equivalent to s.setblocking(1).

4、shutdown(how) -- shut down traffic in one or both directions
引用
Shut down one or both halves of the connection. If how is SHUT_RD, further receives are disallowed. If how is SHUT_WR, further sends are disallowed. If how isSHUT_RDWR, further sends and receives are disallowed. Depending on the platform, shutting down one half of the connection can also close the opposite half (e.g. on Mac OS X, shutdown(SHUT_WR) does not allow further reads on the other end of the connection).

资料参考：
http://docs.python.org/2/library/socket.html