Python 使用正则表达式来爬虫

绝地灬酷狼 2023-10-05 11:27 10阅读 0赞

#### 获取[https://36kr.com/][https_36kr.com]网站首页所有的新闻 ####

操作步骤：

**1、访问本网站,使用手机方式|检查，需要ctrl+F查找你新闻的关键词语**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70][]

**2、找到之后，你可以查看是在<script></script> ，有key:value**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1][]

**3、 编写代码，获取数据**

import re
    import  requests
    import  json
    
    #头部
    headers={"userAgent":"Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Mobile Safari/537.36"}
    
    #URL路径
    url="https://36kr.com/"
    response = requests.get(url,headers=headers)
    str = response.content.decode()
    # print(str)
    
    #查找,使用正在表达式->取数组的第一个
    result=re.findall("<script>window.initialState=(.*?)</script>",str)[0]
    # print(result)
    
    
    #先写入到本地，再查看
    with open("36kr.json","w",encoding="utf-8") as f:
         f.write(result)
    
    #加载json转换成python类型
    json.loads(result)
    print(result)

4、可以先写入到本地上，再通过这个方式来查找是哪里有问题？

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2][]

注意： 往一个文件中写入多个json串，不再是一个json串，不能直接读取

一行写一个json串，按照行来读取

**5、效果：**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3][]

[https_36kr.com]: https://36kr.com/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20201010160945447.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20201010160647935.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20201010161241957.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20201010161355575.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70