Possible error in 'dive into Python' book, help!

[Ben Edwards (lists)]

I have been going through Dive into Python which up to now has been
excellent.  I am now working through Chapter 9, XML Processing.  I am 9
pages in (p182) in the 'Parsing XML section.  The following code is
supposed to return the whole XML document (I have put ti at the end of
this email):

from xml.dom import minidom
 
xmldoc =
minidom.parse('/home/ben/diveintopython-5.4/py/kgp/binary.xml') 
grammerNode = xmldoc.firstChild
 
print grammerNode.toxml()

But it only returns:

<!DOCTYPE grammar
  PUBLIC '-//diveintopython.org//DTD Kant Generator Pro v1.0//EN'
  'kgp.dtd'>

The next line is then 

grammerNode.childNodes

And it returns an empty tuples;(

Kind of stuck here as I don't really want to continue.  Has anyone any
idea what is going on?

Ben

binary.xml

<?xml version="1.0"?>
<!DOCTYPE grammar PUBLIC "-//diveintopython.org//DTD Kant Generator Pro
v1.0//EN" "kgp.dtd">
<grammar>
<ref id="bit">
  <p>0</p>
  <p>1</p>
</ref>
<ref id="byte">
  <p><xref id="bit"/><xref id="bit"/><xref id="bit"/><xref
id="bit"/><xref id="bit"/><xref id="bit"/><xref id="bit"/><xref
id="bit"/></p>
</ref>
</grammar>