import os
from django.contrib.gis.utils import LayerMapping

class GPXMapping(LayerMapping):
    def __init__(self, *args, **kwargs):
        # Setting this environment variable tells OGR to use the elevation
        # attribute as the Z coordinate value on the geometries.  See:
        #  http://www.gdal.org/ogr/drv_gpx.html
        os.environ['GPX_ELE_AS_25D'] = 'YES'
        super(GPXMapping, self).__init__(*args, **kwargs)
        # Unset the environment variable, so it doesn't affect other
        # GPX DataSource objects.
        os.environ.pop('GPX_ELE_AS_25D')