socket 通信代码，单线程

server.py

import socket
sock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
sock.bind(('localhost',7556))
sock.listen(5)
while True:
    connection,address = sock.accept()
    print "client ip is "
    print address
    try:
        connection.settimeout(5)
        buf = connection.recv(1024)
        if buf == '1':
            connection.send('welcome to python server!')
        else:
            connection.send('please go out!')
    except socket.timeout:
        print 'time out'
    finally:
        connection.close()

client.py

import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('localhost',7556))
import time
time.sleep(2)
sock.send('1')
print sock.recv(1024)
sock.close()