1. BeautifulSoup介紹與安裝
1.1 什麼是BeautifulSoup
Beautiful Soup 是一個可以從HTML或XML文件中提取數據的Python庫.它能夠通過轉換器實現慣用的文檔導航,查找,修改文檔的方式
1.2 如何安裝？
首先查看電腦中有沒有BeautifulSoup工具包：pip show beautifulsoup4
直接安裝：pip install beautifulsoup4
1.3 如何導入BeaitufulSoup？
在代碼窗口頂部輸入： from bs4 import BeautifulSoup
1.4 官方案例演示
設置變量，輸入以下html內容，代碼如下
h = """
<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>
"""
soup = BeautifulSoup(h,'lxml')
print(soup)#直接輸出
print(soup.prettify())# 標準化輸出
直接輸出的結果爲
標準化輸出：
<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>
解析標籤
| 查找title標籤 | soup.title |
|---|---|
| 輸出title標籤的名字 | soup.title.name |
| 查找p標籤 | soup.p |
| 輸出p標籤中屬性class的內容 | soup.p[‘class’] |
| 查找a標籤 | soup.a/soup.find(‘a’) |
| 查找所有a標籤 | soup.find_all(‘a’) |
查找title標籤
print(soup.title)
#輸出爲：
<title>The Dormouse's story</title>
輸出title標籤的名字
print(soup.title.name)
#輸出爲：
'tltle'
查找p標籤
print(soup.p)
#輸出爲
<p class="title"><b>The Dormouse's story</b></p>
輸出p標籤中屬性class的內容
print(soup.p['class'])
#輸出爲
['title']
查找a標籤
print(soup.a)
print(soup.find('a'))
#輸出爲
<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>
<a class="sister" href="http://example.com/elsie" id="link1">Elsie</a>
查找所有a標籤
print(soup.find_all('a'))
#輸出爲
[<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>]
直接使用soup.tag(標籤)的輸出結果和使用soup.find(‘tag’)的輸出結果是一樣的，而且都是 <class ‘bs4.element.Tag’>數據類型