PYTHON : How to add root node to an XML

Question

I have an xml file looks something like this

<A>
  <B>
     <C>
       ....
     </C>
  </B>
</A>

I want to add root on top of element 'A'. I found out a way to add elements to root. But How to change existing root and add on top of it using python.

After adding root to the xml it should look like this

<ROOT>
  <A>
    <B>
       <C>
         ....
       </C>
    </B>
  </A>
</ROOT>

Answer 1

import lxml.etree as ET
tree = ET.parse('data')
root = tree.getroot()
newroot = ET.Element("root")
newroot.insert(0, root)
print(ET.tostring(newroot, pretty_print=True))

yields

<root>
  <A>
  <B>
     <C>
       ....
     </C>
  </B>
</A>
</root>

---

But really, unless you need to add something more complicated, simple string formatting could suffice:

with open('data', 'rb') as f, open('newdata', 'wb') as g:
    g.write('<ROOT>{}</ROOT>'.format(f.read()))