keytree 0.2.1

KML utilities for the ElementTree API

Keytree provides several functions for manipulating KML using the ElementTree API. Elements can be adapted to the Python geo interface and then used with packages like Shapely:

>>> data = """<?xml version="1.0" encoding="UTF-8"?>
... <kml xmlns="http://www.opengis.net/kml/2.2">
...   <Document>
...     <Placemark>
...       <name>point</name>
...       <description>Point test</description>
...       <Point>
...         <coordinates>
...           -122.364383,37.824664,0
...         </coordinates>
...       </Point>
...     </Placemark>
...   </Document>
... </kml>
... """
>>> from xml.etree import ElementTree
>>> tree = ElementTree.fromstring(data)
>>> kmlns = tree.tag.split('}')[0][1:]
>>> placemarks = tree.findall('*/{%s}Placemark' % kmlns)
>>> p0 = placemarks[0]
>>> import keytree
>>> f = keytree.feature(p0)
>>> from shapely.geometry import asShape
>>> shape = asShape(f.geometry)
>>> shape.buffer(1.5).exterior.length
9.4209934708642571

Objects like those from geojson that provide the Python geo interface can also be converted to ElementTree API Elements:

>>> from geojson import Feature
>>> f = Feature('1',
...             geometry={
...                 'type': 'Point',
...                 'coordinates': (-122.364383, 37.824663999999999)
...                 },
...             title='Feature 1',
...             summary='The first feature',
...             content='Blah, blah, blah.'
...             )

A Shapely (or geojson) geometry could also be used in place of the dict:

>>> from shapely.geometry import Point
>>> f = Feature('1',
...             geometry=Point(-122.364383, 37.824664),
...             title='Feature 1',
...             summary='The first feature',
...             content='Blah, blah, blah.'
...             )

The first argument to the keytree.element function is an XML context, the created element will have the same namespace as that element:

>>> elem = keytree.element(tree, f)
>>> import pprint
>>> pprint.pprint((elem.tag, elem.text, list(elem)))
('{http://www.opengis.net/kml/2.2}Placemark',
 None,
 [<Element {http://www.opengis.net/kml/2.2}name at ...>,
  <Element {http://www.opengis.net/kml/2.2}Snippet at ...>,
  <Element {http://www.opengis.net/kml/2.2}description at ...>,
  <Element {http://www.opengis.net/kml/2.2}Point at ...>])
>>> pprint.pprint(list((e.tag, e.text, list(e)) for e in elem))
[('{http://www.opengis.net/kml/2.2}name', 'Feature 1', []),
 ('{http://www.opengis.net/kml/2.2}Snippet', 'The first feature', []),
 ('{http://www.opengis.net/kml/2.2}description', 'Blah, blah, blah.', []),
 ('{http://www.opengis.net/kml/2.2}Point',
  None,
  [<{http://www.opengis.net/kml/2.2}Element coordinates at ...>])]