python 协程与IO编程

1.IO操作:就是在计算机内存数据输入/输出(Input/Output)过程;
(1):网络——浏览器查阅文件,把要查询发送命令数据请求给服务器的过程叫Output(往外发过程),服务器传送数据的过程叫Input(接收外面数据过程);
(2):本地——python文件读写操作;
2.IO密集型:
(1).多路同步阻塞(按顺序命令一步走下去):

from bs4 import BeautifulSoup
import requests

HEADERS = {
    'Accept': 'application/json, text/javascript, **; q=0.01',
    'referer': 'https://music.163.com/',
    'x-csrf-token': '',
    'x-requested-with': 'XMLHttpRequest',
    'cookie': ''
    ,
    'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko)'
                  ' Chrome/90.0.4430.212 Safari/537.36'}
  def get_content1(url):
    r = requests.get(url,headers = HEADERS)
    print(url,' >>>>>',[r.text])

def get_content2(url):
    r = requests.get(url,headers = HEADERS)
    print(url,' >>>>>',[r.text])

def get_content3(url):
    r = requests.get(url,headers = HEADERS)
    print(url,' >>>>>',[r.text])
gevent.joinall([
    gevent.spawn(get_page1,'https://www.google.com.cn/'),
    gevent.spawn(get_page2,'https://baike.baidu.com/'),
    gevent.spawn(get_page3,'https://cn.bing.com/'),
])
输出:
https://baike.baidu.com/  >>>>> ['nnnnnnnnnnnnnnnnn