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
host:www.baidu.com

")
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
host:www.baidu.com

')
        elif sk == client2:
            sk.sendall(b'GET /web?query=fdf HTTP/1.0
host:www.sogou.com

')
        else:
            sk.sendall(b'GET /s?wd=alex HTTP/1.0
host:www.oldboyedu.com

')
        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/')   

)