socket发送请求,协程

1.socket发送请求

 1 #发送请求的方式
 2 
 3 #方式一
 4 import requests
 5 
 6 ret = requests.get("https://www.baidu.com/s?wd=abc")
 7 
 8 print(ret.text)
 9 
10 
11 #方式二
12 
13 import socket
14 
15 client = socket.socket()
16 client.connect(("www.baidu.com",80))
17 client.sendall(b"GET /s?wd=alex HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n")
18 chunk_list = []
19 while True:
20     chunk = client.recv(8096)
21     if not chunk:
22         break
23     chunk_list.append(chunk)
24 
25 body = b"".join(chunk_list)
26 print(body.decode("utf-8"))

　　单线程的并发

 1 import socket
 2 import select
 3 
 4 client1 = socket.socket()
 5 client1.setblocking(False)#百度创建链接:非阻塞
 6 
 7 try:
 8     client1.connect(("www.baidu.com",80))
 9 except BlockingIOError as e:
10     pass
11 
12 client2 = socket.socket()
13 client2.setblocking(False)
14 
15 try:
16     client2.connect(("www.baidu.com",80))
17 except BlockingIOError as e:
18     pass
19 
20 client3 = socket.socket()
21 client3.setblocking(False)
22 
23 try:
24     client3.connect(("www.baidu.com",80))
25 except BlockingIOError as e:
26     pass
27 
28 socket_list = [client1,client2,client3]
29 conn_list = [client1,client2,client3]
30 
31 while True:
32     rlist,wlist,elist = select.select(socket_list,conn_list,[],0.005)
33     for sk in wlist:
34         if sk == client1:
35             sk.sendall(b'GET /s?wd=alex HTTP/1.0\r\nhost:www.baidu.com\r\n\r\n')
36         elif sk == client2:
37             sk.sendall(b'GET /web?query=fdf HTTP/1.0\r\nhost:www.sogou.com\r\n\r\n')
38         else:
39             sk.sendall(b'GET /s?wd=alex HTTP/1.0\r\nhost:www.oldboyedu.com\r\n\r\n')
40         conn_list.remove(sk)
41     for sk in rlist:
42         chunk_list = []
43         while True:
44             try:
45                 chunk = sk.recv(8096)
46                 if not chunk:
47                     break
48                 chunk_list.append(chunk)
49             except BlockingIOError as e:
50                 break
51         body = b"".join(chunk_list)
52     
53         sk.close()
54         socket_list.remove(sk)
55     if not socket_list:
56         break

2.协程

 1 import greenlet
 2 
 3 def f1():
 4     print(111)
 5     g2.switch()
 6     print(222)
 7     g2.switch()
 8 
 9 def f2():
10     print(333)
11     g1.switch()
12     print(444)
13 
14 g1 = greenlet.greenlet(f1)
15 g2 = greenlet.greenlet(f2)
16 g1.switch()

协程的IO切换

 1 from gevent import monkey
 2 monkey.patch_all()
 3 import requests
 4 import gevent
 5 
 6 def get_page1(url):
 7     ret = requests.get(url)
 8     print(url,ret.content)
 9 
10 def get_page2(url):
11     ret = requests.get(url)
12     print(url,ret.content)
13 
14 def get_page3(url):
15     ret = requests.get(url)
16     print(url,ret.content)
17 
18 gevent.joinall(
19       gevent.spawn(get_page1,'https://www.python.org/'),
20       gevent.spawn(get_page2, 'https://www.yahoo.com/'),
21       gevent.spawn(get_page3, 'https://github.com/')   
22 
23 )