I created an xml tree with something like this

top = Element('top')
child = SubElement(top, 'child')
child.text = 'some text'

how do I dump it into an XML file? I tried top.write(filename), but the method doesn't exist.

You need to instantiate an ElementTree object and call write() method:

import xml.etree.ElementTree as ETtop = ET.Element('top')
child = ET.SubElement(top, 'child')
child.text = 'some text'tree = ET.ElementTree(top)
tree.write('output.xml')

The contents of the output.xml after running the code:

<top><child>some text</child></top>