Get children node names from one parent

Question

Given the following XML structure

<cmap>
   <tableVersion version="0" />
   <cmap_format_4 platformID="0" platEncID="3" language="0">
      <map code="0x20" name="space" />
      <!-- SPACE -->
      <!--many, many more characters-->
   </cmap_format_4>
   <cmap_format_0 platformID="1" platEncID="0" language="0">
      <map code="0x0" name=".notdef" />
      <!--many, many more characters again-->
   </cmap_format_0>
   <cmap_format_4 platformID="0" platEncID="3" language="0">
      <!--"cmap_format_4" again-->
      <map code="0x20" name="space" />
      <!-- SPACE -->
      <!--more "map" nodes-->
   </cmap_format_4>
</cmap>

I'm trying to step through and get a list of node names at the cmap_format_0 level along with all the code and name nodes beneath them.

Expected outcome

cmap_format_4
0x0   null
0xd   CR
ox20  space
etc...

cmap_format_0
0x0   notdef
0x1   notdeaf
etc...

So far I have

charactersByFontString = "CODE\tCHAR DESC\n"
tree = ET.parse(xmlFile)
root = tree.getroot()

for map in root.iter("map"):
    charactersByFontString += map.attrib["code"] + "\t"
    charactersByFontString += map.attrib["name"] + "\n"

That's getting all of my codes and names. however I cannot get the name of the c_format_n .

for child in root:
    print child.child

does not work as tableversion is its first child, is self-closing, and has no children. (Also I'm not sure if stringing together a bunch of child nodes even works.) child.sibling got me an error. How can I get these children in the cmap_format_n format?

Answer 1

May I suggest XSLT for transforming your input XML?

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output method="text" encoding="UTF-8" indent="yes" />

    <xsl:template match="/cmap">
        <xsl:apply-templates select="*[starts-with(name(), 'cmap_')]" />
    </xsl:template>

    <xsl:template match="*[starts-with(name(), 'cmap_')]">
        <xsl:value-of select="name()" />
        <xsl:text>&#xA;</xsl:text>
        <xsl:apply-templates select="map" />
        <xsl:text>&#xA;</xsl:text>
    </xsl:template>

    <xsl:template match="map">
        <xsl:apply-templates select="@code" />
        <xsl:text>&#x9;</xsl:text>
        <xsl:apply-templates select="@name" />
        <xsl:text>&#xA;</xsl:text>
    </xsl:template>
</xsl:stylesheet>

outputs ( http://xsltransform.net/bFDb2Cu )

cmap_format_4
0x20    space

cmap_format_0
0x0 .notdef

cmap_format_4
0x20    space

An example of how to use XSLT from within Python can be found over here .

I'm not saying that it can't be done the way you attempt it (DOM traversal) - it most definitely can - XSLT is just a much more natural fit for the task.

Answer 2

import xml.etree.ElementTree as ET

xmlFile = "pytest.xml"

out = "CODE\tCHAR DESC\n"

tree = ET.parse(xmlFile)
root = tree.getroot()

for child in root:
    if child.tag[:4] == 'cmap':
        out += child.tag + '\n'
        for grandchild in child:
            out += grandchild.attrib["code"] + '\t'
            out += grandchild.attrib["name"] + '\n'
        out += '\n'

print(out)