Python 如何在使用 Python 写入新值后保持 XML 注释存在？

Question

我有一个 XML 文件然后需要更新一些值。我的 XML 文件包含评论。写完XML本想保留评论，结果没了

这是我的 XML:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Data System -->
<process>
     <!-- Student Name -->
     <NAME source="hsfg" class="hshah" property="Name">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </NAME>
     <!-- Exercise Number -->
     <number source="hsfg" class="hgdgf" property="gagfa">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </number>
     <!-- Exam ID -->
     <id source="hsfg" class="gfdg" property="fadg">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </id>
</process>

这是我需要更新的值

<!-- Student Name -->
     <NAME source="hsfg" class="hshah" property="Name">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </NAME>

变成这样：

<!-- Student Name -->
     <NAME source="hsfg" class="hshah" property="Name">
          <VALUE type="string">new value</VALUE>
          <VALUE type="None"></VALUE>
     </NAME>

我的代码：

read = ET.parse('test.xml').getroot()
parent = read.find('.//NAME[@property="Name"]')
change = parent.find('VALUE[@type="string"]')
change.text = 'new value'
tree = ET.ElementTree(read)
tree.write("test.xml")

test.xml文件的输出变成这样。评论和 <?xml version="1.0" encoding="UTF-8"?> 消失了。

<process>
     
     <NAME source="hsfg" class="hshah" property="Name">
          <VALUE type="string">new value</VALUE>
          <VALUE type="None" />
     </NAME>
     
     <number source="hsfg" class="hgdgf" property="gagfa">
          <VALUE type="string" />
          <VALUE type="None" />
     </number>
     
     <id source="hsfg" class="gfdg" property="fadg">
          <VALUE type="string" />
          <VALUE type="None" />
     </id>
</process>

但我的期望输出、结构和注释仍然与之前相同，更新值如下：

<?xml version="1.0" encoding="UTF-8"?>
<!-- Data System -->
<process>
     <!-- Student Name -->
     <NAME source="hsfg" class="hshah" property="Name">
          <VALUE type="string">new value</VALUE>
          <VALUE type="None"></VALUE>
     </NAME>
     <!-- Exercise Number -->
     <number source="hsfg" class="hgdgf" property="gagfa">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </number>
     <!-- Exam ID -->
     <id source="hsfg" class="gfdg" property="fadg">
          <VALUE type="string"></VALUE>
          <VALUE type="None"></VALUE>
     </id>
</process>

Answer 1

使用ET.XMLParser保留评论
在write()函数中使用encoding和xml_declaration参数编写xml声明试试下面的代码：

import xml.etree.ElementTree as ET
parser = ET.XMLParser(target=ET.TreeBuilder(insert_comments=True))

read = ET.parse('newXml.xml', parser=parser).getroot()
parent = read.find('.//NAME[@property="Name"]')
change = parent.find('VALUE[@type="string"]')
change.text = 'new value'
tree = ET.ElementTree(read)
tree.write("test.xml", encoding='utf-8', xml_declaration=True)

你也可以避免使用变量 read 而只使用 tree:

import xml.etree.ElementTree as ET
parser = ET.XMLParser(target=ET.TreeBuilder(insert_comments=True))

tree = ET.parse('newXml.xml', parser=parser)
parent = tree.find('.//NAME[@property="Name"]')
change = parent.find('VALUE[@type="string"]')
change.text = 'new value'
tree.write("test.xml", encoding='utf-8', xml_declaration=True)

Python 如何在使用 Python 写入新值后保持 XML 注释存在？

Python how to keep the XML comment exist after write a new value using Python?

python

xml

comments