爬虫_041_bs简单使用
2023-03-01 本文已影响0人
为宇绸缪
下面的一段HTML代码将作为例子被多次用到.这是爱丽丝梦游仙境的的一段内容
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>
"""
使用BeautifulSoup解析这段代码,能够得到一个 BeautifulSoup 的对象,并能按照标准的缩进格式的结构输出:
from bs4 import BeautifulSoup
soup = BeautifulSoup(html_doc, 'lxml')
# html进行美化
print(soup.prettify())
匹配代码
<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>
几个简单的浏览结构化数据的方法:
soup.title # 获取标签title
# <title>The Dormouse's story</title>
soup.title.name # 获取标签名称
# 'title'
soup.title.string # 获取标签title内的内容
# 'The Dormouse's story'
soup.title.parent # 获取父级标签
soup.title.parent.name # 获取父级标签名称
# 'head'
soup.p
# <p class="title"><b>The Dormouse's story</b></p>
soup.p['class'] # 获取p的class属性值
# 'title'
soup.a
# <a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>
soup.find_all('a')
# [<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>]
soup.find(id="link3") # 获取id为link3的标签
# <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>
从文档中找到所有<a>标签的链接:
for link in soup.find_all('a'):
print(link.get('href'))
# http://example.com/elsie
# http://example.com/lacie
# http://example.com/tillie
从文档中获取所有文字内容:
print(soup.get_text())
