IO / Read and write KML file with geopandas and fiona driver

kml_io.py

import fiona 
import geopandas as gpd

# Enable fiona driver
gpd.io.file.fiona.drvsupport.supported_drivers['KML'] = 'rw'

# Read file
df = gpd.read_file(path, driver='KML')

# Write file
with fiona.drivers():
    # Might throw a WARNING - CPLE_NotSupported in b'dataset sample_out.kml does not support layer creation option ENCODING'
    df.to_file('sample_out.kml', driver='KML')
    
# Drop Z dimension of polygons that occurs often in kml 
import shapely
import fiona 
import geopandas as gpd

# Enable fiona driver
fiona.supported_drivers['KML'] = 'rw'

# Read file
df = gpd.read_file(path, driver='KML')

# Write file
with fiona.drivers():
    # Might throw a WARNING - CPLE_NotSupported in b'dataset sample_out.kml does not support layer creation option ENCODING'
    df.to_file('sample_out.kml', driver='KML') # You may change driver to GeoJSON

# Drop Z dimension of polygons that occurs often in kml - * expansion handles xy anx xyz cases
import shapely
df = df.set_geometry(
    df.geometry.map(
        lambda polygon: shapely.ops.transform(lambda x, y, *_: (x, y), polygon)
    )
)
# Orient the shape counter clockwise to be Vega conform
df = df.set_geometry(
    df.geometry.map(lambda geom: shapely.geometry.polygon.orient(geom))
)