Python 正则表达式 菜鸟教程已经讲的很详细了，这里给出实例：

爬取斗破苍穹http://www.doupoxs.com/doupocangqiong/1.html

运行截图:

源代码：

import requests
import re
import time

headers = {
    ‘User-Agent‘:‘Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36‘
}

f = open(‘D:/doupo.txt‘,‘a+‘)#新建txt文档，追加的方式

def get_info(url):
    res = requests.get(url,headers=headers)
    if res.status_code == 200:#判断请求吗是否为200
        contents = re.findall(‘<p>(.*?)</p>‘,res.content.decode(‘utf-8‘),re.S)
        for content in contents:
            f.write(content+‘\n‘)#正则获取数据写入txt文件
    else:
        pass  #不为200就pass

if __name__ == ‘__main__‘:
    urls = [‘http://www.doupoxs.com/doupocangqiong/{}.html‘.format(str(i)) for i in range(2,100)]
    for url in urls:
        get_info(url)
        time.sleep(1)
    f.close()

原文地址：https://www.cnblogs.com/sengzhao666/p/12274980.html