这里有新鲜出炉的Python教程,程序狗速度看过来!
Python 是一种面向对象、解释型计算机程序设计语言,由Guido van Rossum于1989年底发明,第一个公开发行版发行于1991年。Python语法简洁而清晰,具有丰富和强大的类库。它常被昵称为胶水语言,它能够把用其他语言制作的各种模块(尤其是C/C++)很轻松地联结在一起。
本篇文章主要介绍了python爬虫之BeautifulSoup 使用select方法详解,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
本文介绍了python爬虫之BeautifulSoup 使用select方法详解 ,分享给大家。具体如下:
- <html><head><title>The Dormouse's story</title></head>
- <body>
- <p class="title" name="dromouse"><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" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="sister" id="link1"><!-- Elsie --></a>,
- <a href="http://example.com/lacie" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="sister" id="link2">Lacie</a> and
- <a href="http://example.com/tillie" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="sister" id="link3">Tillie</a>;
- and they lived at the bottom of a well.</p>
- <p class="story">...</p>
- """
我们在写 CSS 时,标签名不加任何修饰,类名前加点,id名前加 #,在这里我们也可以利用类似的方法来筛选元素,用到的方法是 soup.select(),返回类型是 list
(1)通过标签名查找
- print soup.select('title')
- #[<title>The Dormouse's story</title>]
- print soup.select('a')
- #[<a class="sister" href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link1"><!-- Elsie --></a>, <a class="sister" href="http://example.com/lacie" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, <a class="sister" href="http://example.com/tillie" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link3">Tillie</a>]
- print soup.select('b')
- #[<b>The Dormouse's story</b>]
(2)通过类名查找
- print soup.select('.sister')# [ < a class = "sister"href = "http://example.com/elsie"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"rel = "external nofollow"id = "link1" > <!--Elsie--></a>, <a class="sister" href="http:/ / example.com / lacie " rel="external nofollow " rel="external nofollow " rel="external nofollow " id="link2 ">Lacie</a>, <a class="sister " href="http: //example.com/tillie" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link3">Tillie</a>]
(3)通过 id 名查找
- print soup.select('#link1')
- #[<a class="sister" href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link1"><!-- Elsie --></a>]
(4)组合查找
组合查找即和写 class 文件时,标签名与类名、id名进行的组合原理是一样的,例如查找 p 标签中,id 等于 link1的内容,二者需要用空格分开
- print soup.select('p #link1')
- #[<a class="sister" href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link1"><!-- Elsie --></a>]
直接子标签查找
- print soup.select("head > title")
- #[<title>The Dormouse's story</title>]
(5)属性查找
查找时还可以加入属性元素,属性需要用中括号括起来,注意属性和标签属于同一节点,所以中间不能加空格,否则会无法匹配到。
- print soup.select("head > title")
- #[<title>The Dormouse's story</title>]
- print soup.select('a[href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ]')
- #[<a class="sister" href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link1"><!-- Elsie --></a>]
同样,属性仍然可以与上述查找方式组合,不在同一节点的空格隔开,同一节点的不加空格
- print soup.select('p a[href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ]')
- #[<a class="sister" href="http://example.com/elsie" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" id="link1"><!-- Elsie --></a>]
来源: http://www.phperz.com/article/17/1104/351834.html