from xml.dom import minidom

 xml = """\

 <target depends="create-build-dir" name="build-Folio">

    <property name="project.name" value="Folio"/>

    <ant antfile="build.xml" dir="Folio/FolioUI" inheritall="false" target="package"/>

    <ant antfile="build.xml" dir="Folio/Folio" inheritall="false" target="package"/>

 </target>

 """

 def comment_node(node):

     comment = node.ownerDocument.createComment(node.toxml())

     node.parentNode.replaceChild(comment, node)

     return comment

 def uncomment_node(comment):

     node = minidom.parseString(comment.data).firstChild

     comment.parentNode.replaceChild(node, comment)

     return node

 doc = minidom.parseString(xml).documentElement

 comment_node(doc.getElementsByTagName('ant')[-1])

 xml = doc.toxml()

 print 'comment_node():\n'

 print xml

 print

 doc = minidom.parseString(xml).documentElement

 comment = doc.lastChild.previousSibling

 print 're-parsed comment:\n'

 print comment.toxml()

 print

 uncomment_node(comment)

 print 'uncomment_node():\n'

 print doc.toxml()

 print

Output:

comment_node():<target depends="create-build-dir" name="build-Folio"><property name="project.name" value="Folio"/><ant antfile="build.xml" dir="Folio/FolioUI" inheritall="false" target="package"/><!--<ant antfile="build.xml" dir="Folio/Folio" inheritall="false" target="package"/>--></target>

re-parsed comment:<!--<ant antfile="build.xml" dir="Folio/Folio" inheritall="false" target="package"/>-->

uncomment_node():<target depends="create-build-dir" name="build-Folio"><property name="project.name" value="Folio"/><ant antfile="build.xml" dir="Folio/FolioUI" inheritall="false" target="package"/><ant antfile="build.xml" dir="Folio/Folio" inheritall="false" target="package"/></target>