how to remove an element in lxml
https://stackoverflow.com/questions/7981840/how-to-remove-an-element-in-lxml
import lxml.etree as et
xml="""
<groceries>
<fruit state="rotten">apple</fruit>
<fruit state="fresh">pear</fruit>
<punnet>
<fruit state="rotten">strawberry</fruit>
<fruit state="fresh">blueberry</fruit>
</punnet>
<fruit state="fresh">starfruit</fruit>
<fruit state="rotten">mango</fruit>
<fruit state="fresh">peach</fruit>
</groceries>
"""
tree=et.fromstring(xml)
for bad in tree.xpath("//fruit[@state='rotten']"):
bad.getparent().remove(bad)
print et.tostring(tree, pretty_print=True)