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。
安装：
pip install BeautifulSoup4
导入：
from bs4 import BeautifulSoup
beautifulsoup简单示例:
soup = BeautifulSoup(text, features="html.parser") # 返回第一个对象 v1 = soup.find("div") v1 = soup.find(id="i1") v1 = soup.find("div", id="i1") # 组合使用 # 返回对象列表 v2 = soup.find_all("div") v2 = soup.find_all(id="i1") v2 = soup.find_all("div", id="i1") # 组合使用 tag.text # 获取文本 tag.attrs("href") # 获取属性
代码示例
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')
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、 attrs，标签属性
tag = soup.find('a') attrs = tag.attrs # 获取 print(attrs) tag.attrs = {'ik':123} # 设置 tag.attrs['id'] = 'value' # 设置 print(soup)
3、 children,所有子标签
body = soup.find('body') v = body.children
4、 descendants,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_all(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') # 所有以p开头 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() 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
tag.next tag.next_element tag.next_elements tag.next_sibling tag.next_siblings tag.previous tag.previous_element tag.previous_elements tag.previous_sibling tag.previous_siblings tag.parent tag.parents tag.children tag.descendant
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)
参考：
