CODEWITHSUNDEEP
pythonxmlparsingelementelementtree
CarlosBernardes
CarlosBernardes

Reputation: 1

Change XML grandchild value if child value is equal to another value

I need to correct a few hundred of XML files.

Let's say files are of this format:

<?xml version="1.0" encoding="UTF-8"?>
<MyData xmlns="urn:iso" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:iso">
  <Hdr>
    <AppHdr xmlns="urn:iso" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:iso">
      <St>A</St>
      <To>Z</To>
  </Hdr>
  <Data>
    <Document xmlns="urn:iso" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:iso">
      <CountryReport>
        <RptHdr>
            <RpDtls>
                <Dt>2018-07-10</Dt>
          </RpDtls>
        </RptHdr>
        <Country>
          <Id>PT</Id>
          <FullNm>Portugal</FullNm>>
          <Bd>
            <Tp>US</Tp>
          </Bd>
        </Country>
        <Country>
          <Id>ESP</Id>
          <FullNm>Spain</FullNm>>
          <Bd>
            <Tp>EUR</Tp>
          </Bd>
        </Country>
      </CountryReport>
    </Document>
  </Data>
</MyData>

The replacement I need to do is the following:

I've try different ways using sed, xmllint and ElementTrees using python but without success.

I may be using the wrong xpath but I unfortunately cannot figure it out.

Can you help?

Upvotes: 0

Views: 96

Answers (1)

zx485
zx485

Reputation: 29022

The easiest way to achieve your goal would be using an XSLT-processor. For example, use a script that calls the Linux program xsltproc or the Windows/Linux program saxon.

Because your elements are in a namespace, you have to define it for your elements. For example, add xmlns:ui="urn:iso" to your xsl:stylesheet element and then use the following template in combination with the identity template:

<xsl:template match="ui:Country[ui:Id='PT']/ui:Bd/ui:Tp">
  <xsl:element name="Tp" namespace="{namespace-uri()}">EUR</xsl:element>
</xsl:template>

The identity template of XSLT-1.0 is:

<xsl:template match="node()|@*">
  <xsl:copy>
    <xsl:apply-templates select="node()|@*" />
  </xsl:copy>
</xsl:template>

With XSLT-3.0 you could use the following instruction instead:

<xsl:mode on-no-match="shallow-copy" />

So a complete XSLT-1.0 file to transform all of your XML files could look like:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:ui="urn:iso">
<xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>

  <!-- identity template -->
  <xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*" />
    </xsl:copy>
   </xsl:template>  

  <xsl:template match="ui:Country[ui:Id='PT']/ui:Bd/ui:Tp">
    <xsl:element name="Tp" namespace="{namespace-uri()}">EUR</xsl:element>
  </xsl:template>

</xsl:stylesheet>

An xsltproc bash command could look like

for file in *; do xsltproc transform.xslt $file > $file.NEW; done;

Upvotes: 3

Related Questions