reptile_second

• 知识点回顾
  • robots.txt:

  • UA:

  • 1.指定url
  • 2.发起请求
  • 3.获取页面数据
  • 4.数据解析
  • 5.持久化存储
  • bs4:
    • 实例化bs对象,将页面源代码数据加载到该对象中
    • 定位标签:find('name',class_='someone') findall() select()
    • 将标签中的文本内容获取,strint,text get_txtx() a['href']
• 环境安装: pip install lxml
• 分析原理:
  • 获取页面源码数据
  • 实例化一个etree的对象,并且将页面源码数据加载到哦该对象中
  • 调用该对象的xpath方法进行制定标签的定位
  • 注意: xpath函数必须结合着xpath表达式进行标签定位和内容捕获

项目需求: 解析58 二手房的相关数据

import requests
from lxml import etreeurl = 'https://bj.58.com/shahe/ershoufang/?utm_source=market&spm=u-2d2yxv86y3v43nkddh1.BDPCPZ_BT&PGTID=0d30000c-0047-e4e6-f587-683307ca570e&ClickID=1'
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'
}
page_text = requests.get(url=url,headers=headers).texttree =etree.HTML(page_text)
li_list = tree.xpath('//ul[@class="house-list-wrap"]/li')
fp = open('58.csv','w',encoding='utf-8')
for li in li_list:title = li.xpath('./div[2]/h2/a/text()')[0]price = li.xpath('./div[2]//text()')price = ''.join(price)fp.write(title + ':' + price + '\n')
fp.close()
print('over')

解析图片数据: http://pic.netbian.com/4kmeinv/

# ctrl + shift + x
# - 解析图片数据: http://pic.netbian.com/4kmeinv/
import os
import urllib
import requests
from lxml import etreeurl = 'http://pic.netbian.com/4kmeinv/'
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'
}response = requests.get(url=url,headers=headers)
# response.encording = 'utf-8'if not os.path.exists('./imgs'):os.mkdir('./imgs')
page_text = response.texttree = etree.HTML(page_text)
li_list = tree.xpath('//div[@class="slist"]/ul/li')
for li in li_list:img_name = li.xpath('./a/b/text()')[0]# 处理中文乱码img_name = img_name.encode('iso-8859-1').decode('gbk')img_url = 'http://pic.netbian.com' + li.xpath('./a/img/@src')[0]img_path = './imgs/' + img_name +'.jpg'urllib.request.urlretrieve(url=img_url,filename=img_path)print(img_path, '下载成功!')
print('over!!')

# [重点] 下载煎蛋网中的图片数据:http://jandan.net/ooxx

# [重点] 下载煎蛋网中的图片数据:http://jandan.net/ooxx
# 数据加密 (反扒机制)
import base64
import urllib
import requests
from lxml import etreeurl = 'http://jandan.net/ooxx'
headers = {'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'
}
page_text = requests.get(url=url,headers=headers).texttree = etree.HTML(page_text)
img_hash_list = tree.xpath('//span[@class="img-has"]/text()')
for img_hash in img_hash_list:img_url = 'http:' + base64.b64decode(img_hash).decode()img_name = img_url.split('/')[-1]urllib.request.urlretrieve(url=img_url,filename=img_name)print('over!')

爬取站长素材中的简历模板

import random
import requests
from lxml import etreeheaders = {'Connection':'close', #当请求成功后,马上断开该次请求(及时释放请求池中的资源)'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'
}url = 'http://sc.chinaz.com/jianli/free_%d.html'
for page in range(1,4):if page ==1:new_url = 'http://sc.chinaz.com/jianli/free.html'else:new_url =format(url%page)response = requests.get(url=new_url,headers=headers)response.encoding = 'utf-8'page_text = response.texttree = etree.HTML(page_text)div_list = tree.xpath('//div[@id="container"]/div')for div in div_list:detail_url = div.xpath('./a/@href')[0]name = div.xpath('./a/img/@alt')[0]detail_page = requests.get(url=detail_url,headers=headers).texttree = etree.HTML(detail_page)download_list = tree.xpath('//div[@class="clearfix mt20 downlist"]/ul/li/a/@href')download_url = random.choice(download_list)data = requests.get(url=download_url,headers=headers).contentfileName = name + '.rar'with open(fileName,'wb') as fp:fp.write(data)print(fileName,'下载成功')print('GG')

解析所有城市名称

import requests
from lxml import etreeheaders = {'Connection':'close', #当请求成功后,马上断开该次请求(及时释放请求池中的资源)'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36'
}
url = 'https://www.aqistudy.cn/historydata/'
page_text = requests.get(url=url,headers=headers).tetxtree = etree.HTML(page_text)
li_list = tree.xpath('//div[@class="bottom"]/ul/li |  //div[@class="bottom"]/ul/div[2]/li')for li in li_list:city_name = li.xpath('./a/text()')[0]print(city_name)

代理ip

# 设置请求代理ip: www.goubanjia.com 诀代理 西祠代理
# 代理ip的类型必须和请求url 的协议保持一致
url = 'https://www.baidu.com/s?wd=ip'page_text = requests.get(url=url,headers=headers,proxies={'https':'61.7.170.240:8080'}).textwith open('./ip.html','w',encoding='utf-8') as fp:fp.write(page_text)

tips

• robots
• UA
• 数据加密
• 懒加载
• 代理ip