轻轻学爬虫—scrapy框架巧用8—猴子偷桃(4)
2021/7/8 23:25:33
本文主要是介绍轻轻学爬虫—scrapy框架巧用8—猴子偷桃(4),对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
轻轻学爬虫—scrapy框架巧用8—猴子偷桃(4)
本节课我们来学习bs4库中的常用方法,还是以下面的数据为例子
html_doc = """ <html><head><title>The Dormouse's story</title></head> <body> <p class="title"><b>The Dormouse's story</b></p> <p class="story">Once upon a time there were three little sisters; and their names were <a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>, <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>; and they lived at the bottom of a well.</p> <p class="story">...</p> """ from bs4 import BeautifulSoup soup = BeautifulSoup(html_doc, 'html.parser') soup.prettify() print(soup) #得到下面结构化的html ""“<html> <head> <title> The Dormouse's story </title> </head> <body> <p class="title"> <b> The Dormouse's story </b> </p> <p class="story"> Once upon a time there were three little sisters; and their names were <a class="sister" href="http://example.com/elsie" id="link1"> Elsie </a> , <a class="sister" href="http://example.com/lacie" id="link2"> Lacie </a> and <a class="sister" href="http://example.com/tillie" id="link3"> Tillie </a> ; and they lived at the bottom of a well. </p> <p class="story"> ... </p> </body> </html>"""
过滤器
find_all()查找所有标签以列表形式返回
字符串
print(soup.find_all('b')) # [<b>The Dormouse's story</b>]
正则表达式
正则的部分我们抽空讲解。先知道可以这样写就可以
import re for tag in soup.find_all(re.compile("^b")): print(tag.name) # body # b
列表
如果传入列表参数,Beautiful Soup会将与列表中任一元素匹配的内容返回
print(soup.find_all(["a", "b"])) # [<b>The Dormouse's story</b>, <a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>, <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>]
True
True
可以匹配任何值,下面代码查找到所有的tag,但是不会返回字符串节点
for tag in soup.find_all(True): print(tag.name) # html # head # title # body # p # b # p # a # a # a # p
方法(函数)
如果没有合适过滤器,那么还可以定义一个方法
def has_class_but_no_id(tag): return tag.has_attr('class') and not tag.has_attr('id') soup.find_all(has_class_but_no_id) #[<p class="title"><b>The Dormouse's story</b></p>, <p class="story">Once upon a time there were three #little sisters; and their names were #<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>, #<a class="sister" href="http://example.com/lacie" id="link2">Lacie</a> and #<a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>; #and they lived at the bottom of a well.</p>, <p class="story">...</p>]
find_all()内容比较多,小伙伴们可以先理解一下。后续我们接着来
码字不易,欢迎大家在评论区留言,收藏。或者加入群聊群聊一起进步学习。
这篇关于轻轻学爬虫—scrapy框架巧用8—猴子偷桃(4)的文章就介绍到这儿,希望我们推荐的文章对大家有所帮助,也希望大家多多支持为之网!
- 2024-07-03微信支付提示下单账户与支付账户不一致-icode9专业技术文章分享
- 2024-07-03微信支付提示订单号重复-icode9专业技术文章分享
- 2024-07-02微服务启动nacos注册上去了,但是一直没有收到请求-icode9专业技术文章分享
- 2024-07-02如何检查文件的编码格式-icode9专业技术文章分享
- 2024-07-02sublime 更改编码格式-icode9专业技术文章分享
- 2024-06-30uniAPP 实现全屏左右滚动滚动的效果-icode9专业技术文章分享
- 2024-06-30如何在本地使用授权或插件-icode9专业技术文章分享
- 2024-06-30伪静态规则配置方法汇总-icode9专业技术文章分享
- 2024-06-29易优CMS安装常见问题汇总-icode9专业技术文章分享
- 2024-06-28易优新手必读安装教程-icode9专业技术文章分享