KML bounding box

kmlbbox.py

#!/usr/bin/env python3

import lxml.etree
tree = lxml.etree.parse('pl.kml')
root = tree.getroot()
ns= 'http://earth.google.com/kml/2.1'
pmarks = tree.findall('//{{{0}}}Placemark'.format(ns))
for pmark in pmarks:
  coor= pmark.find('{{{0}}}Point/{{{0}}}coordinates'.format(ns))
  long, lat, alt = (float(x) for x in coor.text.split(',',3))
  if long < 20.6 or long > 21.6 or lat < 52 or lat > 52.6:
    pmark.getparent().remove(pmark)

tree.write('pl-warszawa.kml', pretty_print=True, encoding='utf-8', xml_declaration=True)