07小实例

版权声明：转载请注明出处 https://blog.csdn.net/nanhuaibeian/article/details/86510934

1. 查看网页源代码定位要爬取的信息（谷歌浏览器）

1. 目标网页：https://blog.csdn.net/nanhuaibeian/article/details/85521071

2. 审查网页元素，确定爬取内容
   目标想要爬取这一个列表信息
   

3. 确定网页在div标签下，class属性为‘table-box’
   

4. Console控制台下得到这个table
   

2.爬取下网页并保存

1. 代码实现

import requests
url = 'https://blog.csdn.net/nanhuaibeian/article/details/85521071'
response = requests.get(url)
response.encoding('utf-8')
with open('real_case.html','w') as f:
    f.write(response.text)

2. 由于已经确定获取目标内容的标签为div(class=‘table-box’)，往下进行，会发现，爬取下来的网页内容不含有这一标签，审查元素发现这一标签是通过js设置的
   修改方法从谷歌浏览器将源码下载保存到real_case.html中。

3. 获取目标内容

import requests
import re
from lxml import etree
import html

with open('real_case.html','r',encoding='utf-8') as f:
    c = f.read()
#将换行符全部替换掉
s = re.sub(r'\n',' ',c)
tree = etree.HTML(c)
table_element = tree.xpath("//div[@class='table-box'][1]/table/tbody/tr")
# 正则表达式替换掉'<>'
pattern1_attrib = re.compile(r"<.*?>")
#读取内容
for row in table_element:
    try:
        td1 = row.xpath('td')[0]
        s1 = etree.tostring(td1).decode('utf-8')
        #将'<>'用空替换掉
        s1 = pattern1_attrib.sub('',s1)
        #按照HTML5的定义进行转码
        s1 = html.unescape(s1)

        td2 = row.xpath('td')[1]
        s2 = etree.tostring(td2).decode('utf-8')
        s2 = pattern1_attrib.sub('', s2)
        s2 = html.unescape(s2)
        print(s1,':',s2)

    except Exception as err:
        print('error:',err)
        pass