python协程有多厉害?
爬一个××网站上的东西,测算了一下协程的速度提升到底有多大,网站链接就不放了。。。
import requests from bs4 import BeautifulSoup as sb import lxml import time url = 'http://www.××××.com/html/part/index27_' url_list = [] start = time.time() for i in range(2,47): print('get page '+str(i)) headers = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.78 Safari/537.36'} res = requests.get((url+str(i)+'.html'), headers) res.encoding = 'gb2312' soup = sb(res.text, 'lxml') div = sb(res.text, 'lxml').find('div', class_="box list channel") for li in div.find_all('li'): urls = ('http://www.××××.com' + li.a.get('href')) url_list.append(urls) print(urls) print(url_list) print(time.time()-start)
爬完用时 111.7 s。
来试试协程:
import requests from bs4 import BeautifulSoup as sb import lxml import time from gevent import monkey import gevent monkey.patch_all() url = 'http://www.231ka.com/html/part/index27_' url_list = [] for i in range(2,47): url_list.append(url+str(i)+'.html') def get(url): print('get data from :'+url) headers = { 'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.78 Safari/537.36'} res = requests.get(url, headers) res.encoding = 'gb2312' soup = sb(res.text, 'lxml') div = sb(res.text, 'lxml').find('div', class_="box list channel") for li in div.find_all('li'): ur = ('http://www.231ka.com' + li.a.get('href')) print(ur) start = time.time() task = [] for url in url_list: task.append(gevent.spawn(get,url)) gevent.joinall(task) print(time.time()-start)
结果是: 55.6 s
也就是说在同样是单线程的情况下,采用了协程后可以使得时间缩减一半,而且仅仅是使用了python的第三方协程库实现的。
牛逼了
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