python network programming details and simple examples

  • 2020-05-30 20:32:55
  • OfStack

python network programming details

The patent right for network programming should belong to Unix, and the syntax that each platform (windows, Linux, etc.) and language (C, C++, Python, Java, etc.) implements in accordance with its own characteristics is much the same as that of the language (C, C++, Python, Java, etc.). In my opinion, if you know Unix's socket network programming, you will also know other forms of network programming methods. This is not a very precise statement. If you know the principle of socket programming, you will know the network programming. The difference is that each platform and language has its own exclusive grammar, which we can apply flexibly.

The following is an example of the most basic network programming implemented with python, which is to realize the one-way "data flow" between the client and the server based on the client-server architecture. We use two methods to achieve this, one is the original socket programming, and the other is the use of python object-oriented method to encapsulate the implementation of the first method, in order to reduce the transparency of the implementation and facilitate rapid development.

Requirements: the client enters data, sends it to the server, and the server generates (timestamp + data) encapsulated data in response to the client. Since there are two types of programming in socket: connection-oriented and connectionless, these two correspond to TCP data streams and UDP datagram, respectively. So, we implement both.

1. Python socket programming

Connection-oriented TCP socket programming:


# -*- coding: utf-8 -*-
 3 from socket import *
from time import ctime 

# Address and Port
HOST = ''
PORT = 21567
ADDR = (HOST, PORT)

# BuffSize
BUFSIZ = 1024

# build socket
tcpSerSock = socket(AF_INET, SOCK_STREAM)
# bind socket
tcpSerSock.bind(ADDR)
# listen 5 client 
tcpSerSock.listen(5)

try:
  while True:
    print 'waiting for connection...'
    # build client socket
    tcpCliSock, addr = tcpSerSock.accept()
    print '...connect from:', addr

    # accept data and process
    while True:
      data = tcpCliSock.recv(BUFSIZ)
      if not data:
        break
      tcpCliSock.send('[%s] %s' % (ctime(), data))

      # close client socket 
      tcpCliSock.close()
except EOFError, KeyboardInterrupt:
  tcpSerSock.close()

# -*- coding:utf-8 -*-

from socket import *

# Address and Port 
HOST = '127.0.0.1'
PORT = 21567
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

#build socket 
tcpCliSocket = socket(AF_INET, SOCK_STREAM)
tcpCliSocket.connect(ADDR)

while True:
  data = raw_input('> ')
  if not data:
    break
  # send data
  tcpCliSocket.send(data)
  # recv data
  data = tcpCliSocket.recv(BUFSIZ)
  if not data:
    break
  # show data
  print data
tcpCliSocket.close()

Connectionless UDP socket programming


# -*- coding: utf-8 -*-

from socket import *
from time import ctime 

# Address and Port 
HOST = ''
PORT = 8000
ADDR = (HOST, PORT)

# BufferSize
BUFFSIZE = 1024
# build socket
udpSerSock = socket(AF_INET, SOCK_DGRAM)
# bind socket
udpSerSock.bind(ADDR)

try:
  while True:
    print 'waiting the message...'
    data, addr = udpSerSock.recvfrom(BUFFSIZE)
    print 'received the message: '+data+' from: ', addr
    udpSerSock.sendto('[%s] %s' % (ctime(), data), addr)
except EOFError, KeyboardInterrupt:
  udpSerSock.close()

# -*- coding: utf-8 -*-

from socket import *

# Address and Port 
HOST = 'localhost'
PORT = 8000
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

# build socket 
udpCliSock = socket(AF_INET, SOCK_DGRAM)

while True:
  data = raw_input('> ')
  udpCliSock.sendto(data, ADDR)
  data = udpCliSock.recvfrom(BUFSIZ)
  if not data:
    break
  print data 
udpCliSock.close()

2. Network programming based on encapsulation class SocketServer


# -*- coding: utf-8 -*-

from SocketServer import TCPServer as TCP, StreamRequestHandler as SRH 
from time import ctime 

# Address and Port
HOST = ''
PORT = 21567
ADDR = (HOST, PORT)

# BuffSize
BUFSIZ = 1024

# build RequestHandler
class MyRequestHandler(SRH):
  def handle(self):
    print '...connected from: ', self.client_address
    self.wfile.write('[%s] %s' % (ctime(), self.rfile.readline()))

# build TCPServer
TCPServ = TCP(ADDR, MyRequestHandler)
print 'waiting for connection...'
# loop to process
TCPServ.serve_forever()

# -*- coding:utf-8 -*-

from socket import *

# Address and Port 
HOST = '127.0.0.1'
PORT = 21567
ADDR = (HOST, PORT)

# BufferSize
BUFSIZ = 1024

while True:
  # note: SocketServer  The default behavior of the request handler is to accept the connection, 
  #  You get the request, and then you close the connection, so you need multiple connections 
  tcpCliSock = socket(AF_INET, SOCK_STREAM)
  tcpCliSock.connect(ADDR)

  # process data
  data = raw_input('> ')
  if not data:
    break
  tcpCliSock.send('%s\r\n' % data)

  data = tcpCliSock.recv(BUFSIZ)
  if not data:
    break
  print data.strip()
  tcpCliSock.close()

Thank you for reading, I hope to help you, thank you for your support of this site!


Related articles: