Detailed explanation of the example of socket server implemented by Python based on select

The example of this article describes the socket server implemented by Python based on select. Share it with everyone for your reference, the details are as follows:

Learned from the use of select.select in the asyncore module

import socket
import traceback
import select
EOL1 = b'\n\n'
EOL2 = b'\n\r\n'
socketmap = {}
r,w,e = [],[],[]
response = b'HTTP/1.0 200 OK\r\nDate: Mon, 1 Jan 1996 01:01:01 GMT\r\n'
response += b'Content-Type: text/plain\r\nContent-Length: 13\r\n\r\n'
response += b'Hello, world!'
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serversocket.bind(('0.0.0.0', 23456))
serversocket.listen(1)
#serversocket.setblocking(0)
listening_fileno = serversocket.fileno()
socketmap[listening_fileno] = serversocket
print 'listening_fileno',listening_fileno
try:
  while True:
    r,w,e = [],[],[]
    for fd in socketmap:
      r.append(fd)
      w.append(fd)
      e.append(fd)
    r,w,e = select.select(r,w,e,1)
    for fd in r:
      request = b''
      isocket = socketmap[fd]
      if fd == listening_fileno:
        print 'accepting'
        clientsock,clientaddr = isocket.accept()
        #clientsock.setblocking(0)
        cli_fileno = clientsock.fileno()
        r.append(cli_fileno)
        w.append(cli_fileno)
        e.append(cli_fileno)
        socketmap[cli_fileno] = clientsock
      else:
        print 'reading'
        while EOL1 not in request and EOL2 not in request:
          request += isocket.recv(1024)
        print(request.decode())
    for fd in w:
      print 'writing'
      osocket = socketmap[fd]
      osocket.send(response)
    for fd in e:
      esocket = socketmap[fd]
      print 'socket close',fd
      esocket.close()
      del socketmap[fd]
    print "no data coming"
except Exception,e:
  print traceback.print_exc()
  serversocket.close()

More detailed explanations of Python implementation based on select For related articles about socket server examples, please pay attention to the PHP Chinese website!