request能取到网页上面的数据，但是这些是属于结构化的数据，我们不能直接使用，需要将这些数据进行转化，从而方便使用
BeautifulSoup能将标签移除掉，从而获得网页上的数据以及内容
1、将特定标签的内容取出来
单个标签
from bs4 import BeautifulSoup
html_sample = ‘\<html>\ <body>\<h1 id ="title"> HelloWorld</h1>\<a href="#" class="link">This is link1</a>\<a href="# link2" class = "link"> This is link2</a>\</body>\</html>‘
soup= BeautifulSoup(html_sample,‘html.parser‘)
header=soup.select(‘h1‘)
print(header[0].text)
多个相同的标签
from bs4 import BeautifulSoup
html_sample = ‘\<html>\ <body>\<h1 id ="title"> HelloWorld</h1>\<a href="#" class="link">This is link1</a>\<a href="# link2" class = "link"> This is link2</a>\</body>\</html>‘
soup= BeautifulSoup(html_sample,‘html.parser‘)
header=soup.select(‘a‘)
for alink in header:
print(alink.text)
2、取出含有特定css属性的元素
id前面需要加#
from bs4 import BeautifulSoup
html_sample = ‘\<html>\ <body>\<h1 id ="title"> HelloWorld</h1>\<a href="#" class="link">This is link1</a>\<a href="# link2" class = "link"> This is link2</a>\</body>\</html>‘
soup= BeautifulSoup(html_sample,‘html.parser‘)
header=soup.select(‘#title‘)
print(header)
class前面加.
from bs4 import BeautifulSoup
html_sample = ‘\<html>\ <body>\<h1 id ="title"> HelloWorld</h1>\<a href="#" class="link">This is link1</a>\<a href="# link2" class = "link"> This is link2</a>\</body>\</html>‘
soup= BeautifulSoup(html_sample,‘html.parser‘)
header=soup.select(‘.link‘)
for alink in header:
print(alink.text)
3、取得a标签里面链接的内容
from bs4 import BeautifulSoup
html_sample = ‘\<html>\ <body>\<h1 id ="title"> HelloWorld</h1>\<a href="#" class="link">This is link1</a>\<a href="# link2" class = "link"> This is link2</a>\</body>\</html>‘
soup= BeautifulSoup(html_sample,‘html.parser‘)
header=soup.select(‘a‘)
for alink in header:
print(alink[‘href‘])
原文：http://www.cnblogs.com/zlj1992/p/6106653.html