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本文實(shí)例講述了Python HTML解析器BeautifulSoup用法。分享給大家供大家參考，具體如下：
BeautifulSoup簡介
我們知道，Python擁有出色的內(nèi)置HTML解析器模塊——HTMLParser，然而還有一個(gè)功能更為強(qiáng)大的HTML或XML解析工具——BeautifulSoup（美味的湯），它是一個(gè)第三方庫。簡單來說，BeautifulSoup最主要的功能是從網(wǎng)頁抓取數(shù)據(jù)。本文我們來感受一下BeautifulSoup的優(yōu)雅而強(qiáng)大的功能吧！
BeautifulSoup安裝
BeautifulSoup3 目前已經(jīng)停止開發(fā)，推薦在現(xiàn)在的項(xiàng)目中使用BeautifulSoup4，不過它已經(jīng)被移植到bs4了，也就是說導(dǎo)入時(shí)我們需要 import bs4 ?？梢岳?pip 或者 easy_install 兩種方法來安裝。下面采用pip安裝。
pip install beautifulsoup4 pip install lxml
建議同時(shí)安裝"lxml"模塊，BeautifulSoup支持Python標(biāo)準(zhǔn)庫中的HTML解析器（HTMLParser），還支持一些第三方的解析器，如果我們不安裝它，則 Python 會(huì)使用 Python默認(rèn)的解析器，lxml 解析器更加強(qiáng)大，速度更快，推薦安裝。
創(chuàng)建對象
安裝后，創(chuàng)建對象：
soup = BeautifulSoup(markup='html文件', 'lxml')
格式化輸出：
soup.prettify()
BeautifulSoup四大對象類型
BeautifulSoup將復(fù)雜HTML文檔轉(zhuǎn)換成一個(gè)復(fù)雜的樹形結(jié)構(gòu),每個(gè)節(jié)點(diǎn)都是Python對象,所有對象可以歸納為4種:
1.Tag類型
即HTML的整個(gè)標(biāo)簽，如獲取<title>標(biāo)簽：
print soup.title #<title>The Dormouse's story</title>
Tag有兩個(gè)重要屬性：name，attrs。
name
即HTML的標(biāo)簽名稱：
print soup.name #[document] print soup.head.name #head
attrs
即HTML的標(biāo)簽屬性字典：
print soup.p.attrs
#{'class': ['title'], 'name': 'dromouse'}
如果想要單獨(dú)獲取某個(gè)屬性：
print soup.p['class'] #['title']
2.NavigableString類型
既然我們已經(jīng)得到了整個(gè)標(biāo)簽，那么問題來了，我們要想獲取標(biāo)簽內(nèi)部的文字內(nèi)容怎么辦呢？很簡單，用 string 即可：
print soup.p.string #The Dormouse's story
3.BeautifulSoup類型
BeautifulSoup 對象表示的是一個(gè)文檔的全部內(nèi)容.：
print soup.name # [document]
4.Comment類型
HTML的注釋內(nèi)容，注意的是，不包含注釋符號(hào)。我們首先判斷它的類型，是否為 Comment 類型，然后再進(jìn)行其他操作，如打印輸出：
if type(soup.a.string)==bs4.element.Comment: print soup.a.string #<!-- Elsie -->
遍歷文檔樹
1.子節(jié)點(diǎn)
contents
獲取所有子節(jié)點(diǎn)，返回列表：
print soup.head.contents #[<title>The Dormouse's story</title>]
children
獲取所有子節(jié)點(diǎn)，返回列表生成器：
print soup.head.children #<listiterator object at 0x7f71457f5710> ## 需要遍歷 for child in soup.body.children: print child ## 結(jié)果 <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 class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a> and <a class="sister" 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="link3">Tillie</a>; and they lived at the bottom of a well.</p> <p class="story">...</p>
2.節(jié)點(diǎn)內(nèi)容
string
返回單個(gè)文本內(nèi)容。如果一個(gè)標(biāo)簽里面沒有標(biāo)簽了，那么 string 就會(huì)返回標(biāo)簽里面的內(nèi)容。如果標(biāo)簽里面只有唯一的一個(gè)標(biāo)簽了，那么 string 也會(huì)返回最里面的內(nèi)容。如果tag包含了多個(gè)子節(jié)點(diǎn),tag就無法確定，string 方法應(yīng)該調(diào)用哪個(gè)子節(jié)點(diǎn)的內(nèi)容，string 的輸出結(jié)果是 None。例如：
print soup.head.string print soup.title.string #The Dormouse's story #The Dormouse's story print soup.html.string # None
strings
返回多個(gè)文本內(nèi)容，且包含空行和空格。
stripped_strings
返回多個(gè)文本內(nèi)容，且不包含空行和空格：
for string in soup.stripped_strings: print(repr(string)) # u"The Dormouse's story" # u"The Dormouse's story" # u'Once upon a time there were three little sisters; and their names were' # u'Elsie' # u',' # u'Lacie' # u'and' # u'Tillie' # u';\nand they lived at the bottom of a well.' # u'...'
get_text()方法
返回當(dāng)前節(jié)點(diǎn)和子節(jié)點(diǎn)的文本內(nèi)容。
from bs4 import BeautifulSoup
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 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" 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="sister1" id="link1">Elsie</a>,
<a 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" rel="external nofollow" rel="external nofollow" class="sister2" id="link2">Lacie</a> and
<a 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="sister3" id="link3">Tillie</a>;
and they lived at the bottom of a well.
</p>
<p class="story">...</p>
</body>
</html>
"""
soup = BeautifulSoup(markup=html_doc,features='lxml')
node_p_text=soup.find('p',class_='story').get_text() # 注意class_帶下劃線
print(node_p_text)
# 結(jié)果
Once upon a time there were three little sisters; and their names were
Elsie,
Lacie and
Tillie;
and they lived at the bottom of a well.
3.父節(jié)點(diǎn)
parent
返回某節(jié)點(diǎn)的直接父節(jié)點(diǎn)：
p = soup.p print p.parent.name #body
parents
返回某節(jié)點(diǎn)的所有父輩及以上輩的節(jié)點(diǎn)：
content = soup.head.title.string for parent in content.parents: print parent.name ## 結(jié)果 title head html [document]
4.兄弟節(jié)點(diǎn)
next_sibling
next_sibling 屬性獲取該節(jié)點(diǎn)的下一個(gè)兄弟節(jié)點(diǎn)，結(jié)果通常是字符串或空白，因?yàn)榭瞻谆蛘邠Q行也可以被視作一個(gè)節(jié)點(diǎn)。
previous_sibling
previous_sibling 屬性獲取該節(jié)點(diǎn)的上一個(gè)兄弟節(jié)點(diǎn)。
print soup.p.next_sibling # 實(shí)際該處為空白 print soup.p.prev_sibling #None 沒有前一個(gè)兄弟節(jié)點(diǎn)，返回 None print soup.p.next_sibling.next_sibling #<p class="story">Once upon a time there were three little sisters; and their names were #<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a> and #<a class="sister" 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="link3">Tillie</a>; #and they lived at the bottom of a well.</p> #下一個(gè)節(jié)點(diǎn)的下一個(gè)兄弟節(jié)點(diǎn)是我們可以看到的節(jié)點(diǎn)
next_siblings、previous_siblings
迭代獲取全部兄弟節(jié)點(diǎn)。
5.前后節(jié)點(diǎn)
next_element、previous_element
不是針對于兄弟節(jié)點(diǎn)，而是在于所有節(jié)點(diǎn)，不分層次的前一個(gè)和后一個(gè)節(jié)點(diǎn)。
next_elements、previous_elements
迭代獲取所有前和后節(jié)點(diǎn)。
搜索文檔樹
1.find_all(name=None, attrs={}, recursive=True, text=None, limit=None, **kwargs)
find_all()方法搜索當(dāng)前tag的所有tag子節(jié)點(diǎn)，并判斷是否符合過濾器的條件。
參數(shù)說明
name參數(shù)
name參數(shù)很強(qiáng)大，可以傳多種方式的參數(shù)，查找所有名字為 name 的tag，字符串對象會(huì)被自動(dòng)忽略掉。
（a）傳標(biāo)簽名
最簡單的過濾器是標(biāo)簽名。在搜索方法中傳入一個(gè)標(biāo)簽名參數(shù)，BeautifulSoup會(huì)查找與標(biāo)簽名完整匹配的內(nèi)容，下面的例子用于查找文檔中所有的<a>標(biāo)簽：
print soup.find_all('a')
#[<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, <a class="sister" 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="link3">Tillie</a>]
返回結(jié)果列表中的元素仍然是BeautifulSoup對象。
（b）傳正則表達(dá)式
如果傳入正則表達(dá)式作為參數(shù)，BeautifulSoup會(huì)通過正則表達(dá)式的 match() 來匹配內(nèi)容。下面例子中找出所有以b開頭的標(biāo)簽,這表示<body>和<b>標(biāo)簽都應(yīng)該被找到：
import re
for tag in soup.find_all(re.compile("^b")):
print(tag.name)
# body
# b
（c）傳列表
如果傳入列表參數(shù)，BeautifulSoup會(huì)將與列表中任一元素匹配的內(nèi)容返回。下面代碼找到文檔中所有<a>標(biāo)簽和<b>標(biāo)簽：
soup.find_all(["a", "b"]) # [<b>The Dormouse's story</b>, # <a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, # <a class="sister" 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="link3">Tillie</a>]
（d）傳True
True 可以匹配任何值，下面代碼查找到所有的tag，但是不會(huì)返回字符串節(jié)點(diǎn)：
for tag in soup.find_all(True): print(tag.name) # html # head # title # body # p # b # p # a # a
（e）傳函數(shù)
如果沒有合適過濾器，那么還可以定義一個(gè)方法，方法只接受一個(gè)元素參數(shù)。如果這個(gè)方法返回 True 表示當(dāng)前元素匹配并且被找到，如果不是則反回 False：
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...</p>,
# <p class="story">...</p>]
keyword參數(shù)
注意的是，如果一個(gè)指定名字的參數(shù)不是搜索內(nèi)置的參數(shù)名，搜索時(shí)會(huì)把該參數(shù)當(dāng)作指定名字tag的屬性來搜索，如果包含一個(gè)名字為 id 的參數(shù),BeautifulSoup會(huì)搜索每個(gè)tag的”id”屬性：
soup.find_all(id='link2') # [<a class="sister" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>]
如果傳入 href 參數(shù)，Beautiful Soup會(huì)搜索每個(gè)tag的"href"屬性：
soup.find_all(href=re.compile("elsie"))
# [<a class="sister" 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" 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>]
使用多個(gè)指定名字的參數(shù)可以同時(shí)過濾tag的多個(gè)屬性:
soup.find_all(href=re.compile("elsie"), id='link1')
# [<a class="sister" 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" 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">three</a>]
在這里我們想用 class 過濾，不過 class 是 python 的關(guān)鍵詞，這怎么辦？加個(gè)下劃線就可以：
soup.find_all("a", class_="sister")
# [<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>,
# <a class="sister" 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="link3">Tillie</a>]
attrs參數(shù)
有些tag屬性在搜索不能使用,比如HTML5中的 " data-* " 自定義屬性：
data_soup = BeautifulSoup('<div data-foo="value">foo!</div>')
data_soup.find_all(data-foo="value")
# SyntaxError: keyword can't be an expression
## 但是可以通過 find_all() 方法的 attrs 參數(shù)定義一個(gè)字典參數(shù)來搜索包含特殊屬性的tag
data_soup.find_all(attrs={"data-foo": "value"})
# [<div data-foo="value">foo!</div>]
text參數(shù)
通過 text 參數(shù)可以搜搜文檔中的字符串內(nèi)容。與 name 參數(shù)的可選值一樣，text 參數(shù)接受字符串 、正則表達(dá)式 、列表、True。
soup.find_all(text="Elsie")
# [u'Elsie']
soup.find_all(text=["Tillie", "Elsie", "Lacie"])
# [u'Elsie', u'Lacie', u'Tillie']
soup.find_all(text=re.compile("Dormouse")) # 模糊查找
[u"The Dormouse's story", u"The Dormouse's story"]
limit參數(shù)
find_all() 方法返回全部的搜索結(jié)構(gòu)，如果文檔樹很大那么搜索會(huì)很慢。如果我們不需要全部結(jié)果，可以使用 limit 參數(shù)限制返回結(jié)果的數(shù)量。效果與SQL中的limit關(guān)鍵字類似，當(dāng)搜索到的結(jié)果數(shù)量達(dá)到 limit 的限制時(shí)，就停止搜索返回結(jié)果。
soup.find_all("a", limit=2)
# [<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>]
recursive參數(shù)
調(diào)用tag的 find_all() 方法時(shí)，BeautifulSoup會(huì)檢索當(dāng)前tag的所有子孫節(jié)點(diǎn)，如果只想搜索tag的直接子節(jié)點(diǎn)，可以使用參數(shù) recursive=False。
soup.html.find_all("title")
# [<title>The Dormouse's story</title>]
soup.html.find_all("title", recursive=False)
# []
2.find( name , attrs , recursive , text , **kwargs )
它與 find_all() 方法唯一的區(qū)別是 find_all() 方法的返回結(jié)果是值包含一個(gè)元素的列表，而 find() 方法直接返回結(jié)果。
3.find_parents() 和 find_parent()
find_all() 和 find() 只搜索當(dāng)前節(jié)點(diǎn)的所有子節(jié)點(diǎn)，孫子節(jié)點(diǎn)等。find_parents() 和 find_parent() 用來搜索當(dāng)前節(jié)點(diǎn)的父輩節(jié)點(diǎn)，搜索方法與普通tag的搜索方法相同，搜索文檔搜索文檔包含的內(nèi)容。
4.find_next_siblings() 和 find_next_sibling()
這2個(gè)方法通過 .next_siblings 屬性對當(dāng) tag 的所有后面解析的兄弟 tag 節(jié)點(diǎn)進(jìn)行迭代， find_next_siblings() 方法返回所有符合條件的后面的兄弟節(jié)點(diǎn)，find_next_sibling() 只返回符合條件的后面的第一個(gè)tag節(jié)點(diǎn)。
5.find_previous_siblings() 和 find_previous_sibling()
這2個(gè)方法通過 .previous_siblings 屬性對當(dāng)前 tag 的前面解析的兄弟 tag 節(jié)點(diǎn)進(jìn)行迭代， find_previous_siblings() 方法返回所有符合條件的前面的兄弟節(jié)點(diǎn)，find_previous_sibling() 方法返回第一個(gè)符合條件的前面的兄弟節(jié)點(diǎn)。
6.find_all_next() 和 find_next()
這2個(gè)方法通過 .next_elements 屬性對當(dāng)前 tag 的之后的 tag 和字符串進(jìn)行迭代， find_all_next() 方法返回所有符合條件的節(jié)點(diǎn)， find_next() 方法返回第一個(gè)符合條件的節(jié)點(diǎn)。
7.find_all_previous() 和 find_previous()
這2個(gè)方法通過 .previous_elements 屬性對當(dāng)前節(jié)點(diǎn)前面的 tag 和字符串進(jìn)行迭代，find_all_previous() 方法返回所有符合條件的節(jié)點(diǎn)， find_previous()方法返回第一個(gè)符合條件的節(jié)點(diǎn)。
CSS選擇器
我們在寫 CSS 時(shí)，標(biāo)簽名不加任何修飾，類名前加點(diǎn)，id名前加 #，在這里我們也可以利用類似的方法來篩選元素，用到的方法是 soup.select()，返回類型是 list。
通過標(biāo)簽名查找
print soup.select('title')
#[<title>The Dormouse's story</title>]
print soup.select('a')
#[<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, <a class="sister" 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="link3">Tillie</a>]
print soup.select('b')
#[<b>The Dormouse's story</b>]
通過類名查找
print soup.select('.sister')
#[<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, <a class="sister" 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="link3">Tillie</a>]
通過 id 名查找
print soup.select('#link1')
#[<a class="sister" 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" 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>]
組合查找
組合查找即和寫 class 文件時(shí)，標(biāo)簽名與類名、id名進(jìn)行的組合原理是一樣的，例如查找 p 標(biāo)簽中，id 等于 link1的內(nèi)容，二者需要用空格分開。
print soup.select('p #link1')
#[<a class="sister" 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" 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>]
直接子標(biāo)簽查找：
print soup.select("head > title")
#[<title>The Dormouse's story</title>]
屬性查找
查找時(shí)還可以加入屬性元素，屬性需要用中括號(hào)括起來，注意屬性和標(biāo)簽屬于同一節(jié)點(diǎn)，所以中間不能加空格，否則會(huì)無法匹配到。
print soup.select('a[class="sister"]')
#[<a class="sister" 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" 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" 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" rel="external nofollow" rel="external nofollow" id="link2">Lacie</a>, <a class="sister" 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="link3">Tillie</a>]
print soup.select('a[ 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" 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" 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" 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>]
同樣，屬性仍然可以與上述查找方式組合，不在同一節(jié)點(diǎn)的空格隔開，同一節(jié)點(diǎn)的不加空格：
print soup.select('p a[ 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" 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" 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" 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>]
以上的 select 方法返回的結(jié)果都是列表形式，可以遍歷形式輸出，然后用 string或get_text() 方法來獲取它的內(nèi)容：
soup = BeautifulSoup(html, 'lxml')
print type(soup.select('title'))
print soup.select('title')[0].get_text()
for title in soup.select('title'):
print title.get_text()
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