使用 lxml 部分丢失元素的文本内容

Question

我有一些 HTML 标记，我想在其中删除 <b> 元素的一些 <b> 子元素（它是旧标记...）。

问题：当我使用 Python 和 lxml 删除子元素时，一些包含 <center> 元素的文本消失了。

示例程序（带有简化的说明性标记）：

#!/usr/bin/env python3

from lxml import html, etree
from lxml.etree import tostring

html_snippet = """
<center>
    <b>IT wisdoms</b>
    <b>
        for your <a href="#">brain</a>:
    </b>
    NEVER <a href="#">change a running system</a> before the holidays!
</center>"""

tree = html.fromstring(html_snippet)
center_elem = tree.xpath("//center")[0]

print('----- BEFORE -----')
print(tostring(center_elem, pretty_print=True, encoding='unicode'))
for elem in center_elem.xpath("b"):
    elem.getparent().remove(elem)
print('----- AFTER -----')
print(tostring(center_elem, pretty_print=True, encoding='unicode'))

输出：

----- BEFORE -----
<center>
    <b>IT wisdoms</b>
    <b>
        for your <a href="#">brain</a>:
    </b>
    NEVER <a href="#">change a running system</a> before the holidays!
</center>

----- AFTER -----
<center>
    <a href="#">change a running system</a> before the holidays!
</center>

如您所见，<b> 子元素消失了，但单词 NEVER 消失了，而 <a> 元素和文本 before the holiday! 保留了下来.

我不知道如何保留它！

Answer 1

尝试在要消除的元素上使用drop_tree()：

tree = html.fromstring(html_snippet)
center_elem = tree.xpath("//center")[0]
print('----- BEFORE -----')
print(etree.tostring(center_elem, pretty_print=True, encoding='unicode'))
for elem in center_elem.xpath("b"):
    elem.drop_tree()
print('----- AFTER -----')
print(etree.tostring(center_elem, pretty_print=True, encoding='unicode'))

返回：

----- BEFORE -----
<center>
    <b>IT wisdoms</b>
    <b>
        for your <a href="#">brain</a>:
    </b>
    NEVER <a href="#">change a running system</a> before the holidays!
</center>

----- AFTER -----
<center>


    NEVER <a href="#">change a running system</a> before the holidays!
</center>