我有一个需求，我需要读取一个 XML 文件并用某个值替换一个字符串。 XML 包含 CDATA 元素，我需要保留它。 我试过使用解析器并将 strip_data 设置为 false。这是行不通的，需要帮助才能找到实现它的方法。

import lxml.etree as ET

parser1 = ET.XMLParser(strip_cdata=False)

with open('testxml.xml', encoding="utf8") as f:
tree = ET.parse(f, parser=parser1)

root = tree.getroot()
for elem in root.getiterator():
    try:
        elem.text = elem.text.replace('Bundled Manager 2.2(8b)', '123456')
    except AttributeError:
        pass

tree.write('output_new8.xml', xml_declaration=True, method='xml',  encoding="utf8")

下面是示例 xml:

     <?xml version="1.0" encoding="UTF-8" standalone="no"?><!-- Copyright   (c) 2015 Moto Company, LLC. All rights reserved. Moto Confidential/Proprietary Information -->
<Benchmark>
       <status date="2013-03-11">draft</status>
    <title>Logitech TMM block(TM) System 300 Release Certification Matrix</title>
    <description>Random discription</description>
    <version time="2013-03-05T15:20:20.995-04:00" update="">3.0.0-2017.03.00</version>
        <model system="urn:xccdf:scoring:default"/>
    <Profile id="xccdf_com.Moto_profile_release_4.0.21">
        <status date="2016-03-30">draft</status>
        <title>RCM 4.0.21</title>
        <description><![CDATA[<p>Moto Vblock System 300 Release 4.0.21</p>
<ul><li> TMM VNX OE for File was updated to 7.1.79.8.</li>
</ul>]]>
</description>
        <set-value idref="xccdf_com.Moto_value_vision_content_version">3.0.0-2015.07.00</set-value>
        <set-value idref="xccdf_com.Moto_value_vision_version">3.0.0</set-value>
        <set-value idref="xccdf_com.Moto_value_vplex_version">5.3.0.03.00.04</set-value>
        <set-value idref="xccdf_com.Moto_value_powerpath_version">Bundled Manager 2.2(8b)</set-value>       
        <select idref="xccdf_com.Moto_rule_vnx_version" selected="true"/>
        <select idref="xccdf_com.Moto_rule_vplex_version" selected="true"/>
    </Profile>
</Benchmark>

代码的输出如下所示:

<?xml version='1.0' encoding='UTF8'?>
<!-- Copyright (c) 2015 Moto Company, LLC. All rights reserved. Moto Confidential/Proprietary Information --><Benchmark>
    <status date="2013-03-11">draft</status>
    <title>Logitech TMM block(TM) System 300 Release Certification Matrix</title>
    <description>Random discription</description>
    <version time="2013-03-05T15:20:20.995-04:00" update="">3.0.0-2017.03.00</version>
        <model system="urn:xccdf:scoring:default"/>
    <Profile id="xccdf_com.Moto_profile_release_4.0.21">
        <status date="2016-03-30">draft</status>
        <title>RCM 4.0.21</title>
        <description>&lt;p&gt;Moto Vblock System 300 Release 4.0.21&lt;/p&gt;
&lt;ul&gt;&lt;li&gt; TMM VNX OE for File was updated to 7.1.79.8.&lt;/li&gt;
&lt;/ul&gt;
</description>
        <set-value idref="xccdf_com.Moto_value_vision_content_version">3.0.0-2015.07.00</set-value>
        <set-value idref="xccdf_com.Moto_value_vision_version">3.0.0</set-value>
        <set-value idref="xccdf_com.Moto_value_vplex_version">5.3.0.03.00.04</set-value>
        <set-value idref="xccdf_com.Moto_value_powerpath_version">123456</set-value>        
        <select idref="xccdf_com.Moto_rule_vnx_version" selected="true"/>
        <select idref="xccdf_com.Moto_rule_vplex_version" selected="true"/>
    </Profile>
</Benchmark

>

如您所见，CDATA 部分已被剥离。 如果有人可以在这里帮助我，那就太好了。

最佳答案

这是因为你在做

elem.text = elem.text.replace('Bundled Manager 2.2(8b)', '123456')

用普通文本节点替换 CDATA。

documentation 状态

Note how the .text property does not give any indication that the text content is wrapped by a CDATA section. If you want to make sure your data is wrapped by a CDATA block, you can use the CDATA() text wrapper.

因此，如果你想保留 CDATA 部分，你应该只分配给 elem.text 如果你正在修改它，并指示 lxml 使用 CDATA 部分:

if 'Bundled Manager 2.2(8b)' in elem.text:
    elem.text = ET.CDATA(elem.text.replace('Bundled Manager 2.2(8b)', '123456'))

由于 ElementTree 库的工作方式(整个文本和 cdata 内容被连接起来并在 .text 属性中公开为 str )，实际上不可能知道 CDATA 最初是否被使用过。 (参见 Figuring out where CDATA is in lxml element? 和 the source code )

关于python - 即使在使用 strip_cdata=False 后 CDATA 在 lxml 中被剥离，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44549514/