爬虫必备

Beautiful Soup 4.4.0 文档

BeautifulSoup是一个模块,该模块用于接收一个HTML或XML字符串,然后将其进行格式化,之后便可以使用…

电子游戏平台,爬虫必备—BeautifulSoup,爬虫beautifulsoup

BeautifulSoup是一个模块,该模块用于接收一个HTML或XML字符串,然后将其进行格式化,之后便可以使用他提供的方法进行快速查找指定元素,从而使得在HTML或XML中查找指定元素变得简单。

电子游戏平台 1

 1 from bs4 import BeautifulSoup
 2  
 3 html_doc = """
 4 <html><head><title>The Dormouse's story</title></head>
 5 <body>
 6 asdf
 7     <div class="title">
 8         <b>The Dormouse's story总共</b>
 9         <h1>f</h1>
10     </div>
11 <div class="story">Once upon a time there were three little sisters; and their names were
12     <a  class="sister0" id="link1">Elsfie</a>,
13     <a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and
14     <a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;
15 and they lived at the bottom of a well.</div>
16 ad<br/>sf
17 <p class="story">...</p>
18 </body>
19 </html>
20 """
21  
22 soup = BeautifulSoup(html_doc, features="lxml")
23 # 找到第一个a标签
24 tag1 = soup.find(name='a')
25 # 找到所有的a标签
26 tag2 = soup.find_all(name='a')
27 # 找到id=link2的标签
28 tag3 = soup.select('#link2')

简单示例

  1. name,标签名称

    1 # tag = soup.find(‘a’)
    2 # name = tag.name # 获取
    3 # print(name)
    4 # tag.name = ‘span’ # 设置
    5 # print(soup)

  2. attr,标签属性

    1 # tag = soup.find(‘a’)
    2 # attrs = tag.attrs # 获取
    3 # print(attrs)
    4 # tag.attrs = {‘ik’:123} # 设置
    5 # tag.attrs[‘id’] = ‘iiiii’ # 设置
    6 # print(soup)

  3. children,所有子标签

    1 # body = soup.find(‘body’)
    2 # v = body.children

  4. descendants,所有子子孙孙标签

    1 # body = soup.find(‘body’)
    2 # v = body.descendants

  5. clear,将标签的所有子标签全部清空(保留标签名)

    1 # tag = soup.find(‘body’)
    2 # tag.clear()
    3 # print(soup)

  6. decompose,递归的删除所有的标签

    1 # body = soup.find(‘body’)
    2 # body.decompose()
    3 # print(soup)

  7. extract,递归的删除所有的标签,并获取删除的标签

    1 # body = soup.find(‘body’)
    2 # v = body.extract()
    3 # print(soup)

8. decode,转换为字符串(含当前标签);decode_contents(不含当前标签)

1 # body = soup.find('body')
2 # v = body.decode()
3 # v = body.decode_contents()
4 # print(v)

9. encode,转换为字节(含当前标签);encode_contents(不含当前标签)

1 # body = soup.find('body')
2 # v = body.encode()
3 # v = body.encode_contents()
4 # print(v)

10. find,获取匹配的第一个标签

1 # tag = soup.find('a')
2 # print(tag)
3 # tag = soup.find(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
4 # tag = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
5 # print(tag)
  1. find_all,获取匹配的所有标签

电子游戏平台 2

 1 # tags = soup.find_all('a')
 2 # print(tags)
 3  
 4 # tags = soup.find_all('a',limit=1)
 5 # print(tags)
 6  
 7 # tags = soup.find_all(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')
 8 # # tags = soup.find(name='a', class_='sister', recursive=True, text='Lacie')
 9 # print(tags)
10  
11  
12 # ####### 列表 #######
13 # v = soup.find_all(name=['a','div'])
14 # print(v)
15  
16 # v = soup.find_all(class_=['sister0', 'sister'])
17 # print(v)
18  
19 # v = soup.find_all(text=['Tillie'])
20 # print(v, type(v[0]))
21  
22  
23 # v = soup.find_all(id=['link1','link2'])
24 # print(v)
25  
26 # v = soup.find_all(href=['link1','link2'])
27 # print(v)
28  
29 # ####### 正则 #######
30 import re
31 # rep = re.compile('p')
32 # rep = re.compile('^p')
33 # v = soup.find_all(name=rep)
34 # print(v)
35  
36 # rep = re.compile('sister.*')
37 # v = soup.find_all(class_=rep)
38 # print(v)
39  
40 # rep = re.compile('http://www.oldboy.com/static/.*')
41 # v = soup.find_all(href=rep)
42 # print(v)
43  
44 # ####### 方法筛选 #######
45 # def func(tag):
46 # return tag.has_attr('class') and tag.has_attr('id')
47 # v = soup.find_all(name=func)
48 # print(v)
49  
50  
51 # ## get,获取标签属性
52 # tag = soup.find('a')
53 # v = tag.get('id')
54 # print(v)

View Code

12. has_attr,检查标签是否具有该属性

1 # tag = soup.find('a')
2 # v = tag.has_attr('id')
3 # print(v)

13. get_text,获取标签内部文本内容

1 # tag = soup.find('a')
2 # v = tag.get_text('id')
3 # print(v)

14. index,检查标签在某标签中的索引位置

1 # tag = soup.find('body')
2 # v = tag.index(tag.find('div'))
3 # print(v)
4  
5 # tag = soup.find('body')
6 # for i,v in enumerate(tag):
7 # print(i,v)

15. is_empty_element,是否是空标签(是否可以是空)或者自闭合标签,

     判断是否是如下标签:’br’ , ‘hr’, ‘input’, ‘img’, ‘meta’,’spacer’,
‘link’, ‘frame’, ‘base’

1 # tag = soup.find('br')
2 # v = tag.is_empty_element
3 # print(v)
  1. 当前的关联标签

    1 # soup.next
    2 # soup.next_element
    3 # soup.next_elements
    4 # soup.next_sibling
    5 # soup.next_siblings
    6
    7 #
    8 # tag.previous
    9 # tag.previous_element
    10 # tag.previous_elements
    11 # tag.previous_sibling
    12 # tag.previous_siblings
    13
    14 #
    15 # tag.parent
    16 # tag.parents

  2. 查找某标签的关联标签

    1 # tag.find_next(…)
    2 # tag.find_all_next(…)
    3 # tag.find_next_sibling(…)
    4 # tag.find_next_siblings(…)
    5
    6 # tag.find_previous(…)
    7 # tag.find_all_previous(…)
    8 # tag.find_previous_sibling(…)
    9 # tag.find_previous_siblings(…)
    10
    11 # tag.find_parent(…)
    12 # tag.find_parents(…)
    13
    14 # 参数同find_all

18. select,select_one, CSS选择器

电子游戏平台 3

 1 soup.select("title")
 2  
 3 soup.select("p nth-of-type(3)")
 4  
 5 soup.select("body a")
 6  
 7 soup.select("html head title")
 8  
 9 tag = soup.select("span,a")
10  
11 soup.select("head > title")
12  
13 soup.select("p > a")
14  
15 soup.select("p > a:nth-of-type(2)")
16  
17 soup.select("p > #link1")
18  
19 soup.select("body > a")
20  
21 soup.select("#link1 ~ .sister")
22  
23 soup.select("#link1 + .sister")
24  
25 soup.select(".sister")
26  
27 soup.select("[class~=sister]")
28  
29 soup.select("#link1")
30  
31 soup.select("a#link2")
32  
33 soup.select('a[href]')
34  
35 soup.select('a[href="http://example.com/elsie"]')
36  
37 soup.select('a[href^="http://example.com/"]')
38  
39 soup.select('a[href$="tillie"]')
40  
41 soup.select('a[href*=".com/el"]')
42  
43  
44 from bs4.element import Tag
45  
46 def default_candidate_generator(tag):
47     for child in tag.descendants:
48         if not isinstance(child, Tag):
49             continue
50         if not child.has_attr('href'):
51             continue
52         yield child
53  
54 tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator)
55 print(type(tags), tags)
56  
57 from bs4.element import Tag
58 def default_candidate_generator(tag):
59     for child in tag.descendants:
60         if not isinstance(child, Tag):
61             continue
62         if not child.has_attr('href'):
63             continue
64         yield child
65  
66 tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator, limit=1)
67 print(type(tags), tags)

View Code

19. 标签的内容

 1 # tag = soup.find('span')
 2 # print(tag.string)          # 获取
 3 # tag.string = 'new content' # 设置
 4 # print(soup)
 5  
 6 # tag = soup.find('body')
 7 # print(tag.string)
 8 # tag.string = 'xxx'
 9 # print(soup)
10  
11 # tag = soup.find('body')
12 # v = tag.stripped_strings  # 递归内部获取所有标签的文本
13 # print(v)

20.append在当前标签内部追加一个标签

 1 # tag = soup.find('body')
 2 # tag.append(soup.find('a'))
 3 # print(soup)
 4 #
 5 # from bs4.element import Tag
 6 # obj = Tag(name='i',attrs={'id': 'it'})
 7 # obj.string = '我是一个新来的'
 8 # tag = soup.find('body')
 9 # tag.append(obj)
10 # print(soup)

21.insert在当前标签内部指定位置插入一个标签

1 # from bs4.element import Tag
2 # obj = Tag(name='i', attrs={'id': 'it'})
3 # obj.string = '我是一个新来的'
4 # tag = soup.find('body')
5 # tag.insert(2, obj)
6 # print(soup)

22. insert_after,insert_before 在当前标签后面或前面插入

1 # from bs4.element import Tag
2 # obj = Tag(name='i', attrs={'id': 'it'})
3 # obj.string = '我是一个新来的'
4 # tag = soup.find('body')
5 # # tag.insert_before(obj)
6 # tag.insert_after(obj)
7 # print(soup)

23. replace_with 在当前标签替换为指定标签

1 # from bs4.element import Tag
2 # obj = Tag(name='i', attrs={'id': 'it'})
3 # obj.string = '我是一个新来的'
4 # tag = soup.find('div')
5 # tag.replace_with(obj)
6 # print(soup)

24. 创建标签之间的关系(但不会改变标签的位置)

1 # tag = soup.find('div')
2 # a = soup.find('a')
3 # tag.setup(previous_sibling=a)
4 # print(tag.previous_sibling)

25. wrap,将指定标签把当前标签包裹起来

 1 # from bs4.element import Tag
 2 # obj1 = Tag(name='div', attrs={'id': 'it'})
 3 # obj1.string = '我是一个新来的'
 4 #
 5 # tag = soup.find('a')
 6 # v = tag.wrap(obj1)
 7 # print(soup)
 8  
 9 # tag = soup.find('a')
10 # v = tag.wrap(soup.find('p'))
11 # print(soup)

26. unwrap,去掉当前标签,将保留其包裹的标签

1 # tag = soup.find('a')
2 # v = tag.unwrap()
3 # print(soup)

 

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