Question

I need to suppress all duplicate values in an XML file and keep the final value (refer to the target file).

Kindly help, since I don’t know if I should use xslt, python, or any .NET API

Here is the source file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<catalog>
<cd>
    <artist>Bob Dylan</artist>
</cd>
<cd>
    <title>Hide your heart</title>
</cd>
<cd>
    <title>old_value</title>
    <title>inbetween_value</title>
    <title>new_value</title>
</cd>
</catalog>

The expected target file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<catalog>
<cd>
    <artist>Bob Dylan</artist>
</cd>
<cd>
    <title>Hide your heart</title>
</cd>
<cd>
    <title>new_value</title>
</cd>
</catalog>

Answer 1

There is an extremely simple (no explicit conditionals, no axes) XSLT solution:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output encoding="ISO-8859-1"/>
 <xsl:strip-space elements="*"/>

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

 <xsl:template match="cd/title[not(position() = last())]"/>
</xsl:stylesheet>

When this transformation is applied on the provided XML document:

<catalog>
    <cd>
        <artist>Bob Dylan</artist>
    </cd>
    <cd>
        <title>Hide your heart</title>
    </cd>
    <cd>
        <title>old_value</title>
        <title>inbetween_value</title>
        <title>new_value</title>
    </cd>
</catalog>

the wanted, correct result is produced:

<?xml version="1.0" encoding="ISO-8859-1"?>
<catalog>
   <cd>
      <artist>Bob Dylan</artist>
   </cd>
   <cd>
      <title>Hide your heart</title>
   </cd>
   <cd>
      <title>new_value</title>
   </cd>
</catalog>