实例

1、例如爬取58二手房相关的数据

代码：

 1 import requests
 2 from lxml import etree
 3 
 4 url = 'https://bj.58.com/shahe/ershoufang/?utm_source=market&spm=u-2d2yxv86y3v43nkddh1.BDPCPZ_BT&PGTID=0d30000c-0047-e4e6-f587-683307ca570e&ClickID=1'
 5 headers = {
 6     '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'
 7 }
 8 page_text = requests.get(url=url,headers=headers).text
 9 
10 tree = etree.HTML(page_text)  # 创建一个etree实例对象
11 li_list = tree.xpath('//ul[@class="house-list-wrap"]/li')
12 fp = open('58.csv','w',encoding='utf-8')
13 for li in li_list:
14     title = li.xpath('./div[2]/h2/a/text()')[0]
15     price = li.xpath('./div[3]//text()')
16     price = ''.join(price)
17     fp.write(title+":"+price+'
')
18 fp.close()
19 print('over')

2、爬取高清图片

这里我们用到urllib来快速的存储我们的图片

 1 import requests
 2 from lxml import etree
 3 import os
 4 import urllib
 5 
 6 url = 'http://pic.netbian.com/4kmeinv/'
 7 headers = {
 8     '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'
 9 }
10 response = requests.get(url=url,headers=headers)
11 #response.encoding = 'utf-8'
12 if not os.path.exists('./imgs'):
13     os.mkdir('./imgs')
14 page_text = response.text
15 
16 tree = etree.HTML(page_text)
17 li_list = tree.xpath('//div[@class="slist"]/ul/li')
18 for li in li_list:
19     img_name = li.xpath('./a/b/text()')[0]
20     #处理中文乱码
21     img_name = img_name.encode('iso-8859-1').decode('gbk')
22     img_url = 'http://pic.netbian.com'+li.xpath('./a/img/@src')[0]
23     img_path = './imgs/'+img_name+'.jpg'
24     urllib.request.urlretrieve(url=img_url,filename=img_path)
25     print(img_path,'下载成功!')
26 print('over!!!')

3、下载煎蛋网的图片数据

这里会有常见的反爬机制：数据加密

打开请求返回的response找到加密的图片

原来的element里的HTML是加载好之后的图片地址，不能直接获取

代码：

 1 import requests
 2 from lxml import etree
 3 import base64
 4 import urllib
 5 
 6 headers = {
 7     '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'
 8 }
 9 url = 'http://jandan.net/ooxx'
10 page_text = requests.get(url=url,headers=headers).text
11 
12 tree = etree.HTML(page_text)
13 img_hash_list = tree.xpath('//span[@class="img-hash"]/text()')
14 for img_hash in img_hash_list:
15     img_url = 'http:'+base64.b64decode(img_hash).decode() # 将图片的地址进行解密获取原地址
16     img_name = img_url.split('/')[-1]
17     urllib.request.urlretrieve(url=img_url,filename=img_name)

4、下载简历模板

当在连续请求时，由于请求次数太多ip被禁掉，可以使用代理ip或请求结束的时候断开本次连接

 1 import requests
 2 import random
 3 from lxml import etree
 4 headers = {
 5     '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)
 6     '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'
 7 }
 8 url = 'http://sc.chinaz.com/jianli/free_%d.html'
 9 for page in range(1,4):
10     if page == 1:
11         new_url = 'http://sc.chinaz.com/jianli/free.html'
12     else:
13         new_url = format(url%page)
14     
15     response = requests.get(url=new_url,headers=headers)
16     response.encoding = 'utf-8'
17     page_text = response.text
18 
19     tree = etree.HTML(page_text)
20     div_list = tree.xpath('//div[@id="container"]/div')
21     for div in div_list:
22         detail_url = div.xpath('./a/@href')[0]
23         name = div.xpath('./a/img/@alt')[0]
24 
25         detail_page = requests.get(url=detail_url,headers=headers).text
26         tree = etree.HTML(detail_page)
27         download_list  = tree.xpath('//div[@class="clearfix mt20 downlist"]/ul/li/a/@href')
28         download_url = random.choice(download_list)
29         data = requests.get(url=download_url,headers=headers).content
30         fileName = name+'.rar'
31         with open(fileName,'wb') as fp:
32             fp.write(data)
33             print(fileName,'下载成功')