案例22：爬取豆瓣top250电影

import requests, bs4
#引入requests,bs4库
headers={'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)'}
#为防止被反爬程序识别，添加请求头等信息
for x in range(10):
    url = 'https://movie.douban.com/top250?start=' + str(x*25) + '&filter='
    res = requests.get(url,headers=headers)
    bs = bs4.BeautifulSoup(res.text,'html.parser')
    bs = bs.find('ol',class_="grid_view")
    for titles in bs.find_all('li'):
        num = titles.find('em',class_="").text
        title = titles.find('span',class_="title").text
        comment = titles.find('span',class_="rating_num").text
        url_movie = titles.find('a')['href']

        if titles.find('span',class_="inq") != None:
            tes = titles.find('span',class_="inq").text
            print(num + '.' + title + '——' + comment + '\n' + '推荐语：' + tes +'\n' + url_movie)
        else:
            print(num + '.' + title + '——' + comment + '\n' +'\n' + url_movie)