python正则爬取某段子网站前20页段子(request库)过程解析

import requests
import re
import json

class NeihanSpider(object):
  """内涵段子，百思不得其姐，正则爬取一页的数据"""
  def __init__(self):
    self.temp_url = 'http://www.budejie.com/text/{}' # 网站地址，给页码留个可替换的{}
    self.headers = {
      'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36',
    }

  def pass_url(self, url): # 发送请求，获取响应
    print(url)
    response = requests.get(url, headers=self.headers)
    return response.content.decode()

  def get_first_page_content_list(self, html_str): # 提取第一页的数据
    content_list = re.findall(r'<div class="j-r-list-c-desc">\s*<a href="/detail-.*" rel="external nofollow" rel="external nofollow" rel="external nofollow" >(.+?)</a>', html_str) # 非贪婪匹配
    return content_list

  def save_content_list(self, content_list):
    with open('neihan.txt', 'a', encoding='utf-8') as f:
      for content in content_list:
        f.write(json.dumps(content, ensure_ascii=False))
        f.write('\n') # 换行
      print('成功保存一页！')

  def run(self): # 实现主要逻辑
    for i in range(20): # 只爬取前20页数据
      # 1. 构造url
      # 2. 发送请求，获取响应
      html_str = self.pass_url(self.temp_url.format(i+1))
      # 3. 提取数据
      content_list = self.get_first_page_content_list(html_str)
      # 4. 保存
      self.save_content_list(content_list)

if __name__ == '__main__':
  neihan = NeihanSpider()
  neihan.run()