Python socket network programming
Beginning to learn python, some time ago, I bought two books "python programming from entry to practice" "Python core programming third edition", the first book is mainly about some basic syntax and some basic methods of use, and the second book is a lot of in-depth, they seem to be half-understood, I just saw this part of the network programming, there are still a lot of not quite understand the place, but I think that through the I've been searching for information to learn, and I'm sure I'll be able to understand it sooner or later. .......
The main module used in this section is the socket module, where you can find the socket() function, which is used to create a socket object. Sockets also have their own set of methods, which enable socket-based network communication.
socket() module function
To create a socket, you must use the () function, which has the following general syntax
socket(socket_family, socket_type, protocol=0)
where socket_family is AF_UNIX or AF_INET, socket_type is SOCK_STREAM or SOCK_DGRAM, and protocol is usually omitted, default = 0.
So to create a TCP/IP socket, you can use the following call ().
tcpSock = (socket.AF_INET, socket.SOCK_STREAM)
Also create a UDP/IP socket and call it with the following method
udpSock = (socket.AF_INET, socket.SOCK_DGRAM)
Creating a TCP Server
The process of creating a TCP server is basically as follows, not really code
ss = socket() # Create server sockets
() # Sockets bound to addresses
() #Listening for connections
inf_loop: #Server infinite loop
cs = () # Accept client connections
comm_loop: # Communication loop
()/() # Dialog (receive/send)
() # Close client sockets
() # Close server sockets (optional)
In practice, the basic process of creating a TCP server as described above, may be slightly different but the basic idea should be the same, the following is the real wear pieces of server code:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from socket import * # Introduce the socket attribute into the namespace
HOST = '' #This identifies the bind() method as being able to use any available address.
PORT = 21571 # port number
BUFSIZ = 1024 # Buffer size, 1kb
ADDR = (HOST,PORT) #address ？？？？
tcpSerSocket = socket(AF_INET,SOCK_STREAM) # Create tcp socket
(ADDR) #Bind the address to the socket
(5) # Set up and start socket listening
while True: # Infinite loop, waiting for client to connect
print('waiting for connection...')
tcpCliSocket,addr = () # Passively accept client connections
print('...connected from:',addr)
while True: # Conversation loop, waiting for the client to send a message
data = (BUFSIZ) # Receive client messages
if not data: # If the message is blank, jump out of the dialog loop and close the current connection
break
(data) # If a message is received, return the message to the client unchanged
()
()
Creating a TCP Client
As above, a simple non-code process
cs = socket() # Create client sockets
() # Trying to connect to the server
comm_loop: # Communication loop
()/() # Dialog (send/receive)
() # Close client sockets
Creating a client in practice also translates the above steps
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from socket import *
HOST = 'localhost' # Hostname of the server
PORT = 21571 # port number
BUFSIZ = 1024 # buffer
ADDR = (HOST,PORT) # Address
tcpCliSocket = socket(AF_INET,SOCK_STREAM) # Create client sockets
(ADDR) # Connect to the server
while True: # Communication loop
data = input('> ') # Client input information
if not data: # If the input message is empty, the loop is jumped out and the communication is closed
break
data = (data)
(data) # Send client information
data = (BUFSIZ) # Accepting server returns
if not data: # Close the communication loop if no information is returned by the server
break
print('get:',('utf-8'))
()
Of course, this is only the most basic communication, and about the host name, port number and so on is not very understandable for the time being, so far all I have done is to communicate on the same computer, and the port number needs to be the same, if different computers to communicate how to do it? I'm still just a noob .....
Thanks for reading, I hope this helps, and thanks for supporting this site!