BeautifulSoup - 走看看

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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，之后遍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。

from bs4 import BeautifulSoup

html_doc = """

<html><head><title>The Dormouse's story</title></head>

<body>

asdf

    <div class="title">

        <b>The Dormouse's story总共</b>

        <h1>f</h1>

    </div>

<div class="story">Once upon a time there were three little sisters; and their names were

    <a class="sister0" id="link1">Els<span>f</span>ie</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.</div>

ad<br/>sf

<p class="story">...</p>

</body>

</html>

"""

soup = BeautifulSoup(html_doc, features="lxml")

# 找到第一个a标签

tag1 = soup.find(name='a')

# 找到所有的a标签

tag2 = soup.find_all(name='a')

# 找到id＝link2的标签

tag3 = soup.select('#link2')

安装：

pip install beautifulsoup4

使用示例：
from bs4 import BeautifulSoup

html_doc = """

<html><head><title>The Dormouse's story</title></head>

<body>

    ...

</body>

</html>

"""

soup = BeautifulSoup(html_doc, features="lxml")

1. name，标签名称

# tag = soup.find('a')
# name = tag.name # 获取

# print(name)

# tag.name = 'span' # 设置

# print(soup)

2. attr，标签属性

# tag = soup.find('a')
# attrs = tag.attrs    # 获取

# print(attrs)

# tag.attrs = {'ik':123} # 设置

# tag.attrs['id'] = 'iiiii' # 设置

# print(soup)

3. children,所有子标签

# body = soup.find('body')
# v = body.children

4. children,所有子子孙孙标签

# body = soup.find('body')
# v = body.descendants

5. clear,将标签的所有子标签全部清空（保留标签名）

# tag = soup.find('body')
# tag.clear()

# print(soup)

6. decompose,递归的删除所有的标签

# body = soup.find('body')
# body.decompose()

# print(soup)

7. extract,递归的删除所有的标签，并获取删除的标签

# body = soup.find('body')
# v = body.extract()

# print(soup)

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

# body = soup.find('body')

# v = body.decode()

# v = body.decode_contents()

# print(v)

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

# body = soup.find('body')

# v = body.encode()

# v = body.encode_contents()

# print(v)

10. find,获取匹配的第一个标签

# tag = soup.find('a')

# print(tag)

# tag = soup.find(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie')

# tag = soup.find(name='a', class_='sister', recursive=True, text='Lacie')

# print(tag)

11. find_all,获取匹配的所有标签

# tags = soup.find_all('a') # print(tags) # tags = soup.find_all('a',limit=1) # print(tags) # tags = soup.find_all(name='a', attrs={'class': 'sister'}, recursive=True, text='Lacie') # # tags = soup.find(name='a', class_='sister', recursive=True, text='Lacie') # print(tags) # ####### 列表 ####### # v = soup.find_all(name=['a','div']) # print(v) # v = soup.find_all(class_=['sister0', 'sister']) # print(v) # v = soup.find_all(text=['Tillie']) # print(v, type(v[0])) # v = soup.find_all(id=['link1','link2']) # print(v) # v = soup.find_all(href=['link1','link2']) # print(v) # ####### 正则 ####### import re # rep = re.compile('p') # rep = re.compile('^p') # v = soup.find_all(name=rep) # print(v) # rep = re.compile('sister.*') # v = soup.find_all(class_=rep) # print(v) # rep = re.compile('http://www.oldboy.com/static/.*') # v = soup.find_all(href=rep) # print(v) # ####### 方法筛选 ####### # def func(tag): # return tag.has_attr('class') and tag.has_attr('id') # v = soup.find_all(name=func) # print(v) # ## get,获取标签属性 # tag = soup.find('a') # v = tag.get('id') # print(v)

　12. has_attr,检查标签是否具有该属性

# tag = soup.find('a')

# v = tag.has_attr('id')

# print(v)

13. get_text,获取标签内部文本内容

# tag = soup.find('a')
# v = tag.get_text('id')

# print(v)

14. index,检查标签在某标签中的索引位置

# tag = soup.find('body')
# v = tag.index(tag.find('div'))

# print(v)

# tag = soup.find('body')

# for i,v in enumerate(tag):

# 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'

# tag = soup.find('br')

# v = tag.is_empty_element

# print(v)

16. 当前的关联标签

# soup.next

# soup.next_element

# soup.next_elements

# soup.next_sibling

# soup.next_siblings

#

# tag.previous

# tag.previous_element

# tag.previous_elements

# tag.previous_sibling

# tag.previous_siblings

#

# tag.parent

# tag.parents

17. 查找某标签的关联标签

# tag.find_next(...)

# tag.find_all_next(...)

# tag.find_next_sibling(...)

# tag.find_next_siblings(...)

# tag.find_previous(...)

# tag.find_all_previous(...)

# tag.find_previous_sibling(...)

# tag.find_previous_siblings(...)

# tag.find_parent(...)

# tag.find_parents(...)

# 参数同find_all

18. select,select_one, CSS选择器

soup.select("title")

soup.select("p nth-of-type(3)")

soup.select("body a")

soup.select("html head title")

tag = soup.select("span,a")

soup.select("head > title")

soup.select("p > a")

soup.select("p > a:nth-of-type(2)")

soup.select("p > #link1")

soup.select("body > a")

soup.select("#link1 ~ .sister")

soup.select("#link1 + .sister")

soup.select(".sister")

soup.select("[class~=sister]")

soup.select("#link1")

soup.select("a#link2")

soup.select('a[href]')

soup.select('a[href="http://example.com/elsie"]')

soup.select('a[href^="http://example.com/"]')

soup.select('a[href$="tillie"]')

soup.select('a[href*=".com/el"]')

from bs4.element import Tag

def default_candidate_generator(tag):

    for child in tag.descendants:

        if not isinstance(child, Tag):

            continue

        if not child.has_attr('href'):

            continue

        yield child

tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator)

print(type(tags), tags)

from bs4.element import Tag

def default_candidate_generator(tag):

    for child in tag.descendants:

        if not isinstance(child, Tag):

            continue

        if not child.has_attr('href'):

            continue

        yield child

tags = soup.find('body').select("a", _candidate_generator=default_candidate_generator, limit=1)

print(type(tags), tags)

19. 标签的内容

# tag = soup.find('span')

# print(tag.string)          # 获取

# tag.string = 'new content' # 设置

# print(soup)

# tag = soup.find('body')

# print(tag.string)

# tag.string = 'xxx'

# print(soup)

# tag = soup.find('body')

# v = tag.stripped_strings # 递归内部获取所有标签的文本

# print(v)

20.append在当前标签内部追加一个标签

# tag = soup.find('body')

# tag.append(soup.find('a'))

# print(soup)

#

# from bs4.element import Tag

# obj = Tag(name='i',attrs={'id': 'it'})

# obj.string = '我是一个新来的'

# tag = soup.find('body')

# tag.append(obj)

# print(soup)

21.insert在当前标签内部指定位置插入一个标签

# from bs4.element import Tag

# obj = Tag(name='i', attrs={'id': 'it'})

# obj.string = '我是一个新来的'

# tag = soup.find('body')

# tag.insert(2, obj)

# print(soup)

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

# from bs4.element import Tag

# obj = Tag(name='i', attrs={'id': 'it'})

# obj.string = '我是一个新来的'

# tag = soup.find('body')

# # tag.insert_before(obj)

# tag.insert_after(obj)

# print(soup)

23. replace_with 在当前标签替换为指定标签

# from bs4.element import Tag

# obj = Tag(name='i', attrs={'id': 'it'})

# obj.string = '我是一个新来的'

# tag = soup.find('div')

# tag.replace_with(obj)

# print(soup)

24. 创建标签之间的关系

# tag = soup.find('div')

# a = soup.find('a')

# tag.setup(previous_sibling=a)

# print(tag.previous_sibling)

25. wrap，将指定标签把当前标签包裹起来

# from bs4.element import Tag

# obj1 = Tag(name='div', attrs={'id': 'it'})

# obj1.string = '我是一个新来的'

#

# tag = soup.find('a')

# v = tag.wrap(obj1)

# print(soup)

# tag = soup.find('a')

# v = tag.wrap(soup.find('p'))

# print(soup)

26. unwrap，去掉当前标签，将保留其包裹的标签

# tag = soup.find('a')

# v = tag.unwrap()

# print(soup)
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原文地址：https://www.cnblogs.com/jcwit/p/7784357.html