Python爬虫爬取、解析数据操作示例

import requests
import re
import csv
import pymysql
from bs4 import BeautifulSoup
from lxml import etree
import lxml
from lxml import html

class DDSpider(object):
  #对象属性 参数 关键字 页数
  def __init__(self,key='python',page=1):
    self.url = 'http://search.dangdang.com/"]name[\'\"].*"]title[\'\"].*"](.*"].*"](.*"].*"]itemlist-title[\'\"].*"]detail[\'\"].*?>(.*"]search_now_price[\'\"].*?>(.*"]search_book_author[\'\"].*?><span>.*"]itemlist-author[\'\"].*"](.*"].*"search_nature_rg"]/ul/li')
      result = []
      for i in range(len(li_all)):
        title = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="name"]/a/@title'.format(i+1))
        url = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="name"]/a/@href'.format(i+1))
        price = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]//span[@class="search_now_price"]/text()'.format(i+1))
        author_num = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="search_book_author"]/span[1]/a'.format(i+1))
        if len(author_num) != 0:
          #有作者 a标签
          author = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="search_book_author"]/span[1]/a[1]/@title'.format(i+1))
        else:
          #没有作者 a标签
          author = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="search_book_author"]/span[1]/text()'.format(i+1))
        desc = html.xpath('//div[@id="search_nature_rg"]/ul/li[{}]/p[@class="detail"]/text()'.format(i+1))
        my_tuple = (" ".join(title)," ".join(url)," ".join(desc)," ".join(price)," ".join(author))
        result.append(my_tuple)
        
    return result
  
  #私有对象方法 存储数据 1 txt 2 csv 3 mysql
  def __my_save(self,data,save_type=1):
    #循环遍历
    for value in data:
      if save_type == 1:
        with open('ddw.txt','a+',encoding="utf-8") as f:
          f.write('【名称】：{}【作者】：{}【价格】：{}【简介】：{}【链接】：{}'.format(value[0],value[4],value[3],value[2],value[1]))
      elif save_type == 2:
        with open('ddw.csv','a+',newline='',encoding='utf-8-sig') as f:
          writer = csv.writer(f)
          #转化为列表 存储
          writer.writerow(list(value))
      else:
        conn = pymysql.connect(host='127.0.0.1',user='root',passwd='',db='',port=3306,charset='utf8')
        cursor = conn.cursor()
        sql = ''
        cursor.execute(sql)
        conn.commit()
        cursor.close()
        conn.close()
  #公有对象方法 执行所有爬虫操作
  def my_run(self,parser_type=1,save_type=1):
    my_url = self.__my_url()
    for value in my_url:
      result = self.__my_request(value,parser_type)
      self.__my_save(result,save_type)

if __name__ == '__main__':
  #实例化创建对象
  dd = DDSpider('python',0)
  #参数 解析方式 my_run(parser_type,save_type)
  # parser_type 1 利用正则 2 bs4 3 xpath 
  #存储方式 save_type 1 txt 2 csv 3 mysql
  dd.my_run(2,1)