网络编程

requests库

1. 使用python 下载图片

   from threading import Thread
   import requests
   
   class Download(Thread):
       def __init__(self, url):
           super().__init__()
           self.__url = url
   
       def run(self):
           fileName = self.__url[self.__url.rfind('/')+1:] # 获取文件名，从左一个/开始后面的
           resp = requests.get(self.__url)
           with open(fileName, "wb") as f:
               f.write(resp.content)
   
   def main():
       Download(r"https://allinit-1317182407.cos.ap-nanjing.myqcloud.com/others/y/%E5%A3%81%E7%BA%B8.png").start()
   
   
   main()

TCP套接字

套接字的分类

1. TCP套接字（流套接字）
2. 数据报套接字
3. 原始套接字

TCP套接字

1. 端口

   1024一下的是著名服务端口

多并发通信

server.py

from http import server
from socket import socket,SOCK_STREAM,AF_INET
from datetime import datetime
import socketserver
from threading import Thread
import time

from numpy import add

class Server():
    def __init__(self):
        self.server=socket(family=AF_INET,type=SOCK_STREAM)
        self.server.bind(('192.168.211.195',35555))
        self.server.listen(512)
        print("begin.....")

    def server_connet(self):
        num=0
        while True:
            client,addr=self.server.accept()
            num+=1
            print(f"现在有{num}个client")
            Thread(target=self.client_session,args=(client,addr))
         

    def client_session(self,client: socket,addr):
        print(f"{addr}  连接到服务器")
        recv_message=client.recv(1024).decode('utf-8')
        print(f"client{client} time :{datetime.now()} 发来一条信息:{recv_message}")


def main():
    server=Server()
    server.server_connet()

if __name__=="__main__":
    main()
    
   

client.py

from socket import socket,SOCK_STREAM,AF_INET
from time import sleep

def client():
    client=socket()
    client.connect(("192.168.211.195",35555))
    send_message=f"august nihao!".encode('utf-8')
    client.send(send_message)
    client.close()

for i in range(0,50):
    client()
    sleep(1)

UDP 套接字

UDP无需建立连接就可以发送信息

并且直需要在开启socket的时候使用不同的网络流就可以了

udp是SOCK_DGRAM

然后发送数据使用sendto()

接收信息使用recvfrom()

client