如何根据 Python 条件查找和删除 XML 文件（name_spaces）中的元素

Question

我有一个 XML 文件，我想根据条件从中删除元素。但是，XML 文件的命名空间由于某些不明确的原因不允许我执行描述的过程：, 2, , and .

我的 XML 看起来像这样：

    <?xml version='1.0' encoding='UTF-8'?>
        <PcGts xmlns="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15/pagecontent.xsd">
            <Page imageFilename="1.png">
                <TextRegion custom="a">
                    <TextLine custom="readingOrder {index:0;}" id="Ar0010001l1">
                        <TextEquiv>
                            <Unicode> abc </Unicode>
                        </TextEquiv>
                    </TextLine>
                    <TextLine custom="readingOrder {index:1;}" id="Ad0010100l2">
                        <TextEquiv>
                            <Unicode />
                        </TextEquiv>
                </TextRegion>
            </Page>
        </PcGts>

我的目标是清除 "Unicode" 标签中没有文本的所有 TextLine 节点。所以输出将是：

    <?xml version='1.0' encoding='UTF-8'?>
        <PcGts xmlns="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15/pagecontent.xsd">
            <Page imageFilename="1.png">
                <TextRegion custom="a">
                    <TextLine custom="readingOrder {index:0;}" id="Ar0010001l1">
                        <TextEquiv>
                            <Unicode> abc </Unicode>
                        </TextEquiv>
                    </TextLine>
                </TextRegion>
            </Page>
        </PcGts>

我尝试使用上面链接中的一些建议。但是：

 import lxml.etree as ET
 data = ET.parse(file)
 root = data.getroot()
 for x in root.xpath("//Unicode"):
     print(x.text)

没有找到任何标签。再试一次：

for x in root.xpath("//{http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15}Unicode"):
   print(x.text)

抛出 "XPathEvalError: Invalid expression"

嗯，从这个 XML 文件中删除所有 Unicode 标记为空的节点的最简单方法是什么（以及如何找到它们？）？

谢谢。

Answer 1

首先，您 xml 缺少 <TextLine custom="readingOrder {index:1;}" id="Ad0010100l2"> 的结束标记，但如果您将其插入适当的位置，则应使用以下内容：

my_xml = """[your xml above, corrected]"""
data = ET.XML(my_xml.encode('ascii'))
for target in data.xpath("//*[local-name() = 'Unicode'][not(text())]"):
    target.getparent().remove(target)     

print(etree.tostring(data,  xml_declaration=True))

输出：

    <?xml version=\'1.0\' encoding=\'ASCII\'?>\n
<PcGts
    xmlns="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2013-07-15/pagecontent.xsd">
    <Page imageFilename="1.png">
        <TextRegion custom="a">
            <TextLine custom="readingOrder {index:0;}" id="Ar0010001l1">
                <TextEquiv>
                    <Unicode> abc </Unicode>
                </TextEquiv>
            </TextLine>
            <TextLine custom="readingOrder {index:1;}" id="Ad0010100l2">
                <TextEquiv/>
            </TextLine>
        </TextRegion>
    </Page>
</PcGts>

Answer 2

好吧，我终于找到了解决问题的方法。

import lxml.etree as ET
my_xml = """...xml content..."""
data = ET.XML(my_xml.encode('UTF-8'))

#this loop remove "<Unicode />" tags.
for target in data.xpath("//*[local-name() = 'Unicode'][not(text())]"):
    target.getparent().remove(target)  

#and this loop remove nodes without children like "<TextEquiv><Unicode /></TextEquiv>" 
#(after the removing of "<Unicode />")
for el in data.iter():
    if len(list(el.iterchildren())) or ''.join([_.strip() for _ in el.itertext()]):
        pass
    else:
        parent = el.getparent()
        if parent is not None:
            parent.remove(el)
#and this loop remove nodes without children again, but now - it's "<TextLine>" tag
for el in data.iter():
    if len(list(el.iterchildren())) or ''.join([_.strip() for _ in el.itertext()]):
        pass
    else:
        parent = el.getparent()
        if parent is not None:
            parent.remove(el)

print(ET.tostring(data,  xml_declaration=True))

想法来自

如何根据 Python 条件查找和删除 XML 文件（name_spaces）中的元素

How to find and remove elements in XML file (with name_spaces) by condition with Python

python

xml

lxml