Попробуйте xml.etree.ElementTree . Вот короткий пример создания пары точек в файле KML:
from xml.etree import ElementTree as et
class Kml(object):
def __init__(self):
self.root = et.Element('kml')
self.doc = et.SubElement(self.root,'Document')
def add_placemark(self,name,desc,lat,long,alt):
pm = et.SubElement(self.doc,'Placemark')
et.SubElement(pm,'name').text = name
et.SubElement(pm,'description').text = desc
pt = et.SubElement(pm,'Point')
et.SubElement(pt,'coordinates').text = '{},{},{}'.format(lat,long,alt)
def write(self,filename):
tree = et.ElementTree(self.root)
tree.write(filename)
kml = Kml()
kml.add_placemark('Location1','Description1',-120,45,0)
kml.add_placemark('Location2','Description2',60,-45,0)
kml.write('out.kml')