#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2020/3/31 0031 20:36
# @Author  : skye
# @Site    : 
# @File    : 遍历文档节点2.py
# @Software: PyCharm
from bs4 import BeautifulSoup
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 href="http://example.com/elsie" class="sister" id="link1">Elsie</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.
</p> 
<p class="story">...</p> 
</body> 
</html> 
'''
soup=BeautifulSoup(doc,"lxml")
print(soup.name)
tag=soup.find("b")#由此可见<b>节点的父节点依次为<p>、<body>、<html> 
while tag:
    print(tag.name)
    tag=tag.parent