socket发送请求,协程

1.socket发送请求

 #发送请求的方式

 #方式一
 import requests

 ret = requests.get("https://www.baidu.com/s?wd=abc")

 print(ret.text)

 #方式二

 import socket

 client = socket.socket()
 client.connect(("www.baidu.com",80))
 client.sendall(b"GET /s?wd=alex HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n")
 chunk_list = []
 while True:
     chunk = client.recv(8096)
     if not chunk:
         break
     chunk_list.append(chunk)

 body = b"".join(chunk_list)
 print(body.decode("utf-8"))

　　单线程的并发

 import socket
 import select

 client1 = socket.socket()
 client1.setblocking(False)#百度创建链接:非阻塞

 try:
     client1.connect(("www.baidu.com",80))
 except BlockingIOError as e:
     pass

 client2 = socket.socket()
 client2.setblocking(False)

 try:
     client2.connect(("www.baidu.com",80))
 except BlockingIOError as e:
     pass

 client3 = socket.socket()
 client3.setblocking(False)

 try:
     client3.connect(("www.baidu.com",80))
 except BlockingIOError as e:
     pass

 socket_list = [client1,client2,client3]
 conn_list = [client1,client2,client3]

 while True:
     rlist,wlist,elist = select.select(socket_list,conn_list,[],0.005)
     for sk in wlist:
         if sk == client1:
             sk.sendall(b'GET /s?wd=alex HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n')
         elif sk == client2:
             sk.sendall(b'GET /web?query=fdf HTTP/1.0\r\nhost:www.sogou.com\r\n\r\n')
         else:
             sk.sendall(b'GET /s?wd=alex HTTP/1.0\r\nhost:www.oldboyedu.com\r\n\r\n')
         conn_list.remove(sk)
     for sk in rlist:
         chunk_list = []
         while True:
             try:
                 chunk = sk.recv(8096)
                 if not chunk:
                     break
                 chunk_list.append(chunk)
             except BlockingIOError as e:
                 break
         body = b"".join(chunk_list)

         sk.close()
         socket_list.remove(sk)
     if not socket_list:
         break

2.协程

 import greenlet

 def f1():
     print(111)
     g2.switch()
     print(222)
     g2.switch()

 def f2():
     print(333)
     g1.switch()
     print(444)

 g1 = greenlet.greenlet(f1)
 g2 = greenlet.greenlet(f2)
 g1.switch()

协程的IO切换

 from gevent import monkey
 monkey.patch_all()
 import requests
 import gevent

 def get_page1(url):
     ret = requests.get(url)
     print(url,ret.content)

 def get_page2(url):
     ret = requests.get(url)
     print(url,ret.content)

 def get_page3(url):
     ret = requests.get(url)
     print(url,ret.content)

 gevent.joinall(
       gevent.spawn(get_page1,'https://www.python.org/'),
       gevent.spawn(get_page2, 'https://www.yahoo.com/'),
       gevent.spawn(get_page3, 'https://github.com/')   

 )