修改XML文件分割值
修改XML文件分割值
提问于 2017-09-12 13:07:47
我希望通过对xml文件中的值进行除法来修改它们。
我需要将se:SvgParameter[name="stroke-width"]和se:Size的值除以3.6。我在Python.org，修改XML文件上找到了这个教程，但是它似乎不起作用，在这里我也找不到类似的东西。任何帮助或观点都将不胜感激！
下面是一些XML示例，但我希望能够将脚本输出到一个包含多个文件的文件夹中，并将其转换为所有文件。
XML：
<?xml version="1.0" encoding="ISO-8859-1"?>
<StyledLayerDescriptor version="1.1.0" xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd" xmlns:se="http://www.opengis.net/se">
<NamedLayer>
<se:Name>QGIS_SLD_ScaleProblem</se:Name>
<se:Description>
<se:Title>QGIS_SLD_ScaleProblem</se:Title>
<se:Abstract>This SLD is in Pixels, but QGIS will read it as mm</se:Abstract>
</se:Description>
<UserStyle>
<se:Name>QGIS_SLD_ScaleProblem</se:Name>
<se:FeatureTypeStyle>
<se:Rule>
<se:Name>QGIS_SLD_ScaleProblem_Line</se:Name>
<se:LineSymbolizer>
<se:Name>Line</se:Name>
<se:Stroke>
<se:SvgParameter name="stroke">#FF0000</se:SvgParameter>
<se:SvgParameter name="stroke-width">36</se:SvgParameter>
</se:Stroke>
</se:LineSymbolizer>
</se:Rule>
<se:Rule>
<se:Name>QGIS_SLD_ScaleProblem_Point</se:Name>
<se:PointSymbolizer>
<se:Name>Point</se:Name>
<se:Graphic>
<se:Mark>
<se:WellKnownName>circle</se:WellKnownName>
<se:Fill>
<se:SvgParameter name="fill">#FF0000</se:SvgParameter>
</se:Fill>
</se:Mark>
<se:Size>36</se:Size>
</se:Graphic>
</se:PointSymbolizer>
</se:Rule>
</se:FeatureTypeStyle>
</UserStyle>
</NamedLayer>
</StyledLayerDescriptor>代码：
import xml.etree.ElementTree as ET
from lxml import etree
tree = ET.parse('QGIS-SLD-ScaleProblem_Line.sld')
root = tree.getroot()
# To check that the script is reading the correct file
print("SLD file", root[0][0].text, "loaded.")
# Registers namespaces to prevent them being filled with defaults
ET.register_namespace('', "http://www.opengis.net/sld")
ET.register_namespace('ogc', "http://www.opengis.net/ogc")
ET.register_namespace('xsi', "http://www.w3.org/2001/XMLSchema-instance")
ET.register_namespace('xlink', "http://www.w3.org/1999/xlink")
ET.register_namespace('schemaLocation', "http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd")
ET.register_namespace('se', "http://www.opengis.net/se")
# This section "should" search the XML for se:SvgParameter name="stroke-width" and se:Size and divide the value by 3.6
for SvgParameter in root.iter('SvgParameter'):
new_SvgParameter = int(SvgParameter.text) / 3.6
SvgParameter.text = str(new_SvgParameter)
for Size in root.iter('Size'):
new_Size= int(Size.text) / 3.6
Size.text = str(new_Size)
tree.write("GIS-SLD-ScaleFixed.sld", xml_declaration=True, encoding='ISO-8859-1')我看过的答案：
回答 1
Stack Overflow用户
回答已采纳
发布于 2017-09-12 14:52:52
以XSLT为例，这是一种特殊用途的语言，旨在转换XML文件。Python的lxml模块可以运行XSLT1.0脚本。此外，XSLT可以在Python之外运行，因此它是可移植的。
只需调用同一性变换按原样复制整个文档，然后在选定的节点上运行除法。这种方法不需要for循环或if逻辑。
XSLT (另存为.xsl文件，一个特殊的格式良好的XML文件)
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:se="http://www.opengis.net/se">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="se:SvgParameter[@name='stroke-width']|se:Size">
<xsl:copy>
<xsl:apply-templates select="@*"/>
<xsl:value-of select="format-number(text(), '#') div 3.6"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>Python (在循环中的进程下面迭代多个文件)
import lxml.etree as et
# LOAD XML AND XSL
doc = et.parse('Input.xml')
xsl = et.parse('XSLTScript.xsl')
# TRANSFORM
transform = et.XSLT(xsl)
result = transform(doc)
# OUTPUT TO SCREEN
print(result)
# OUTPUT TO FILE
with open('Output.xml', 'wb') as f:
f.write(result)输出
<?xml version="1.0"?>
<StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:se="http://www.opengis.net/se" version="1.1.0" xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.1.0/StyledLayerDescriptor.xsd">
<NamedLayer>
<se:Name>QGIS_SLD_ScaleProblem</se:Name>
<se:Description>
<se:Title>QGIS_SLD_ScaleProblem</se:Title>
<se:Abstract>This SLD is in Pixels, but QGIS will read it as mm</se:Abstract>
</se:Description>
<UserStyle>
<se:Name>QGIS_SLD_ScaleProblem</se:Name>
<se:FeatureTypeStyle>
<se:Rule>
<se:Name>QGIS_SLD_ScaleProblem_Line</se:Name>
<se:LineSymbolizer>
<se:Name>Line</se:Name>
<se:Stroke>
<se:SvgParameter name="stroke">#FF0000</se:SvgParameter>
<se:SvgParameter name="stroke-width">10</se:SvgParameter>
</se:Stroke>
</se:LineSymbolizer>
</se:Rule>
<se:Rule>
<se:Name>QGIS_SLD_ScaleProblem_Point</se:Name>
<se:PointSymbolizer>
<se:Name>Point</se:Name>
<se:Graphic>
<se:Mark>
<se:WellKnownName>circle</se:WellKnownName>
<se:Fill>
<se:SvgParameter name="fill">#FF0000</se:SvgParameter>
</se:Fill>
</se:Mark>
<se:Size>10</se:Size>
</se:Graphic>
</se:PointSymbolizer>
</se:Rule>
</se:FeatureTypeStyle>
</UserStyle>
</NamedLayer>
</StyledLayerDescriptor>页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/46177301
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