子标签和后代标签: .children 和 .descendants

昨天看书，没有用enumurate枚举的时候，直接print，完全发觉不了他们的区别，倍感困惑。

今天看了其他人写的教程，用了枚举法，终于，终于，发现它们之间的区别啦！敲锣打鼓，掌声响起来

还要注意，子代接下一个子代时，可能是换行符，看下面children找出的子代，你就可以体会到啦！
descendants是找了子标签，然后再一步步探入别人的家中，把一个个后代，按辈分由大往小找着。

下面以这段html作为栗子：

html ="""
<html>
    <head>
        <title>The Dormouse's story</title>
    </head>
    <body>
        <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">
                <span>Elsie</span>
            </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>
"""

1.说说我们的 .children

输入：

from bs4 import BeautifulSoup

soup1 = BeautifulSoup(html, 'lxml')
print(soup1.p.children)
for i, child in enumerate(soup1.p.children):
    print(i, child)

输出：

<list_iterator object at 0x000000DD59609898>
0 
            Once upon a time there were three little sisters; and their names were
            
1 <a class="sister" href="http://example.com/elsie" id="link1">
<span>Elsie</span>
</a>
2 

3 <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>
4  
            and
            
5 <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>
6 
            and they lived at the bottom of a well.

2.说说我们的 .descendants

输入：

from bs4 import BeautifulSoup

soup2 = BeautifulSoup(html, 'lxml')
print(soup2.p.children)
for i, desc in enumerate(soup2.p.descendants):
    print(i, desc)

输出：

<list_iterator object at 0x000000DD595897B8>
0 
            Once upon a time there were three little sisters; and their names were
            
1 <a class="sister" href="http://example.com/elsie" id="link1">
<span>Elsie</span>
</a>
2 

3 <span>Elsie</span>
4 Elsie
5 

6 

7 <a class="sister" href="http://example.com/lacie" id="link2">Lacie</a>
8 Lacie
9  
            and
            
10 <a class="sister" href="http://example.com/tillie" id="link3">Tillie</a>
11 Tillie
12 
            and they lived at the bottom of a well.

形象点说，就是假设现在小区里要调查房屋入住情况。
.children呢，找出每一户，登记一下有没人住，就完事了。
而 .descendants呢，就不一样了。登记完每一户的入住情况后，还要登记每间房的入住情况，
每间房分别住了谁，兴趣、职业、爱好、户口所在地……

势必把你查清查楚。
哎呀，妈呀，好可怕！

这就是他们的区别了

最近天气热到爆炸，老天可否大发慈悲一回？

我要融化了
化了
了

posted @ 2019-07-15 22:59  喜欢吃面的猪猪  阅读(1289)  评论(0)  编辑  收藏  举报