socket

module

import socket

TCP Server

HOST = ''                
PORT = 50007             
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
    s.bind((HOST, PORT))
    s.listen(1)
    conn, addr = s.accept()
    with conn:
        print('Connected by', addr)
        while True:
            data = conn.recv(1024)
            if not data: break
            conn.sendall(data)

TCP Client

HOST = '192.168.2.52'   
PORT = 60000             
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
    s.connect((HOST, PORT))
    s.sendall(b'Hello, world')
    data = s.recv(1024)
print('Received', repr(data))

UDP Server,

import socket
import sys

HOST = '' #INADDR_ANY               
PORT = 50007             
with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
    s.bind((HOST, PORT))
    print("Listening %s:%d" % (HOST, PORT))
    while True:
        data, addr = s.recvfrom(1024)
        print(data)
        print(addr)
        s.sendto(data, addr)

UDP Client

Example 1

HOST = '192.168.2.52'   
PORT = 60001          
with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
    s.connect((HOST, PORT))
    s.sendall(b'Hello, world')
    data = s.recv(1024)
print('Received', repr(data))

Example 2

import socket
import struct

HOST = '127.0.0.1'   
PORT = 60000         
with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
    s.connect((HOST, PORT))
    dataRequest = struct.pack(">hif", 64, 65536, 12.3)
    print(f'Request: {dataRequest.hex()} {dataRequest}')
    s.sendall(dataRequest)
    dataReceive = s.recv(1024)
    print(f'Received: {dataReceive.hex()} {dataReceive}')

Socket families

AF表示ADDRESS FAMILY 地址族，PF表示PROTOCOL FAMILY 协议族，在windows系统中，这两个宏定义是一样的，所以使用哪个都没有关系。

1. socket.AF_UNIX（IPC本地进程间通信）: The address of an AF_UNIX socket bound to a file system node is represented as a string
2. socket.AF_INET（TCP/IP通信协议）: A pair (host, port) is used for the AF_INET address family

socket.bind(address)

A pair (host, port) is used for the AF_INET address family, where host is a string representing either a hostname in internet domain notation like ‘daring.cwi.nl’ or an IPv4 address like ‘100.50.200.5’, and port is an integer.

For IPv4 addresses, two special forms are accepted instead of a host address: ‘’ represents INADDR_ANY, which is used to bind to all interfaces, and the string ‘' represents INADDR_BROADCAST. This behavior is not compatible with IPv6

TCP & UDP

• TCP: SOCK_STREAM
• UDP: SOCK_DGRAM

byte 转int

byte_seq = b'\x00\x01'  # 示例字节序列
int_val = int.from_bytes(byte_seq, byteorder='big')  # 默认使用大端模式
print(int_val)  # 输出: 256

struct

import struct

res = struct.pack("i",1234566)  # 传入的必须是 int 类型
print(res)          # b'\x86\xd6\x12\x00'  (查看内容)
print(type(res))    # <class 'bytes'>      (查看类型)

res2 = struct.unpack("i",res)   # 使用什么 Format 打包就用什么解包
print(res2)         # (1234566,)           (是个元组)
print(type(res2))   # <class 'tuple'>      (查看类型)
print(res2[0])      # 1234566  


res = struct.pack("hiq",12,23,451312)  # 传入多个值, 并使用不同的 Fromat
print(res)  # b'\x0c\x00\x00\x00\x17\x00\x00\x00\xf0\xe2\x06\x00\x00\x00\x00\x00'
print(type(res))  # <class 'bytes'>

a,b,c = struct.unpack("hiq",res)  # 使用解压赋值，有几个值就需要有几个 Fromat
print(a,b,c)                      # 12 23 451312