https://www.douban.com/robots.txt
robots.txt 相应网站的爬虫协议，注意看有没有不让抓取的网页
import requests
from bs4 import BeautifulSoup
r =requests.get("https://book.douban.com/subject/4923621/")
soup =BeautifulSoup(r.text,"lxml")
pattern =soup.find_all("span","short")
for item in pattern:
print(item.string)
