How to Read and Plot a KML (Keyhole Markup Language) File in Python ?

Published: June 23, 2025
Updated: June 24, 2025
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Published: June 23, 2025

Updated: June 24, 2025

DMCA.com Protection Status

Introduction

To read a KML file (Keyhole Markup Language, commonly used with Google Earth) in Python, you can use several libraries depending on your needs. This guide covers reading, troubleshooting, and visualizing KML files using geopandas, folium, and alternative libraries like fastkml and pykml.

Table of contents

Generate Fake KML Files for Testing

To test your code without real KML files, you can create dummy files.

Simple KML File (Single Layer with Points)

Save this as simple.kml:

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<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document>
    <name>Simple KML Example</name>
    <Placemark>
      <name>Point A</name>
      <Point>
        <coordinates>-122.0822,37.4223,0</coordinates>
      </Point>
    </Placemark>
    <Placemark>
      <name>Point B</name>
      <Point>
        <coordinates>-122.0850,37.4230,0</coordinates>
      </Point>
    </Placemark>
  </Document>
</kml>

Multi-Layer KML File (Using Folders)

Save this as multi_layer.kml:

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<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document>
    <name>Multi-Layer KML Example</name>

    <Folder>
      <name>Layer 1 - Red Points</name>
      <Placemark>
        <name>Red Point 1</name>
        <Point>
          <coordinates>-122.1,37.4,0</coordinates>
        </Point>
      </Placemark>
    </Folder>

    <Folder>
      <name>Layer 2 - Blue Points</name>
      <Placemark>
        <name>Blue Point 1</name>
        <Point>
          <coordinates>-122.2,37.5,0</coordinates>
        </Point>
      </Placemark>
      <Placemark>
        <name>Blue Point 2</name>
        <Point>
          <coordinates>-122.3,37.6,0</coordinates>
        </Point>
      </Placemark>
    </Folder>

  </Document>
</kml>

Reading KML Files with geopandas

First, ensure geopandas is installed:

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pip install geopandas

Read a Simple KML File

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import geopandas as gpd

gdf = gpd.read_file("simple.kml", driver='KML')
print(gdf.head())

Example Output

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Name description timestamp begin end altitudeMode  tessellate  extrude  \
0  Point A        None       NaT   NaT NaT         None          -1        0
1  Point B        None       NaT   NaT NaT         None          -1        0

visibility  drawOrder  icon                        geometry
0          -1        NaN  None  POINT Z (-122.0822 37.42229 0)
1          -1        NaN  None     POINT Z (-122.085 37.423 0)

Read Specific Layers from a Multi-layer KML File

Python Code

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# List layers
import fiona
print(fiona.listlayers("multi_layer.kml"))

# Read first layer
gdf = gpd.read_file("multi_layer.kml", driver='KML', layer=0)
print(gdf.head())

Example Output

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Name description timestamp begin end altitudeMode  tessellate  \
0  Red Point 1        None       NaT   NaT NaT         None          -1

extrude  visibility  drawOrder  icon                 geometry
0        0          -1        NaN  None  POINT Z (-122.1 37.4 0)

Troubleshooting Common Errors

❌ IndexError: index 0 is out of bounds for axis 0 with size 0

If you get the error:

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IndexError: index 0 is out of bounds for axis 0 with size 0

It means that the KML file was successfully read, but the layer you tried to access contains no features — the file is valid, but empty for that specific layer.

Before accessing a specific layer, it's a good idea to inspect which layers exist and how many features they contain.

First, install Fiona: Fiona is a Python library for reading and writing spatial data formats like GeoPackage, Shapefile, and KML. It provides a simpler, Pythonic interface to GDAL for vector data, and supports reading from multi-layer formats (e.g., KML, GPKG, zipped datasets, cloud storage, etc.).

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pip install fiona

Then use the following code to list the layers in your KML file:

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import fiona

layers = fiona.listlayers("multi_layer.kml")
print(f"Number of layers: {len(layers)}")
print("Layer names:", layers)

Example Output

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Number of layers: 2
Layer names: ['Layer 1 - Red Points', 'Layer 2 - Blue Points']

❌ DriverError: unsupported driver: 'KML'

Solution: Install GDAL with KML support.

Ubuntu/Debian:

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sudo apt-get install gdal-bin libgdal-dev

macOS (Homebrew):

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brew install gdal

Conda (Recommended):

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conda install -c conda-forge gdal fiona geopandas

Then check supported drivers:

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import fiona
print(fiona.supported_drivers)

You should see 'KML': 'rw' in the list.

❌ TypeError: Object of type Timestamp is not JSON serializable

Occurs when plotting with folium.

Fix: Convert datetime columns to string:

Python Code

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import pandas as pd

gdf = gdf.copy()
for col in gdf.columns:
    if pd.api.types.is_datetime64_any_dtype(gdf[col]):
        gdf[col] = gdf[col].astype(str)

gdf = gdf.applymap(lambda x: str(x) if isinstance(x, (pd.Timestamp, pd.Timedelta)) else x)

Visualizing KML Files with folium

1. Install folium:

Bash

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pip install folium

2. Display KML on an Interactive Map

Python Code:

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import geopandas as gpd
import folium

# Load KML file
gdf = gpd.read_file("simple.kml", driver='KML')

# Center map
center = gdf.geometry.iloc[0].centroid.coords[:][0][::-1]
m = folium.Map(location=center, zoom_start=10)

# Fix datetime issues
gdf = gdf.applymap(lambda x: str(x) if isinstance(x, pd.Timestamp) else x)

# Add GeoJSON layer
folium.GeoJson(gdf).add_to(m)

# Export map
m.save("map_with_kml.html")

How to Read and Plot a KML (Keyhole Markup Language) File in Python ?
How to Read and Plot a KML (Keyhole Markup Language) File in Python ?

Optional: Static Plot with GeoPandas

Python Code:

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gdf.plot()

Note: This generates a static image, not interactive.

Alternatives to GeoPandas

fastkml: Efficient and lightweight

Bash

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pip install fastkml

Python Code:

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from fastkml import kml

with open("simple.kml", "rt", encoding="utf-8") as f:
    doc = f.read()

k = kml.KML()
k.from_string(doc)

for feature in k.features():
    for placemark in feature.features():
        print("Name:", placemark.name)
        print("Geometry:", placemark.geometry)

pykml: For detailed XML tree parsing

Bash

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pip install pykml

Python Code:

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from pykml import parser

with open("simple.kml") as f:
    root = parser.parse(f).getroot()

for placemark in root.Document.Placemark:
    print(placemark.name)
    print(placemark.Point.coordinates)

Summary

  • Use geopandas for reading and analyzing KML geospatial data.
  • Use folium for interactive web maps.
  • Use fastkml or pykml for lightweight parsing or full control.
  • Check your GDAL/KML support if you run into driver errors.
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Benjamin

Hi, I'm Ben, the Founder of moonbooks.org. I work as a research scientist specializing in Earth satellite remote sensing, particularly focusing on Fire detection using VIIRS and ABI sensors. My areas of expertise include Python, Machine Learning, and Open Science. Feel free to reach out if you notice any errors on the site. I am constantly striving to enhance it. Thank you!

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