如何使用fastkml与Python3.6创建多几何体（含多点与线）

I’ve dealt with this exact mismatch between Shapely and fastkml’s expected geometry types before—no need to hack the library source! Here are two reliable approaches:

Option 1: Convert Shapely Geometry to pygeoif Types #

Since fastkml is designed to work with pygeoif geometric objects under the hood, you can convert your existing Shapely geometries to their pygeoif equivalents seamlessly:

First, import the required modules:

from shapely.geometry import Point, LineString, GeometryCollection as ShapelyGC
from pygeoif import GeometryCollection as PygeoifGC
from fastkml import KML, Placemark

Build your Shapely geometries, then convert the collection to pygeoif:

# Define your points and line using Shapely
point1 = Point(0, 0)
point2 = Point(1, 1)
connecting_line = LineString([(0, 0), (1, 1)])

# Create a Shapely GeometryCollection, then convert to pygeoif's version
shapely_collection = ShapelyGC([point1, point2, connecting_line])
pygeoif_collection = PygeoifGC(shapely_collection)

Assign the converted collection to your Placemark and generate the KML:

# Set up the KML structure
kml_doc = KML()
main_folder = kml_doc.new_folder(name="Multi-Geometry Items")
multi_geom_placemark = main_folder.new_placemark(name="Two Points + Connecting Line")

# Assign the pygeoif geometry (this won't throw type errors!)
multi_geom_placemark.geometry = pygeoif_collection

# Output the formatted KML
print(kml_doc.to_string(prettyprint=True))

Option 2: Use pygeoif Directly #

If you don’t strictly need Shapely’s advanced features, you can build your geometries directly with pygeoif to avoid conversion entirely:

from pygeoif import Point, LineString, GeometryCollection
from fastkml import KML, Placemark

# Build geometries directly with pygeoif
point1 = Point(0, 0)
point2 = Point(1, 1)
connecting_line = LineString([(0, 0), (1, 1)])
multi_geometry = GeometryCollection([point1, point2, connecting_line])

# Assemble the KML
kml_doc = KML()
main_folder = kml_doc.new_folder(name="Multi-Geometry Items")
multi_geom_placemark = main_folder.new_placemark(name="Two Points + Connecting Line")
multi_geom_placemark.geometry = multi_geometry

# Generate KML output
print(kml_doc.to_string(prettyprint=True))

Why Your Original Approach Failed #

Fastkml’s geometry.py explicitly imports and expects pygeoif.GeometryCollection, not shapely.geometry.GeometryCollection. These are distinct classes, so passing a Shapely collection triggers a type check error. By either converting Shapely objects to pygeoif or using pygeoif directly, you align with the library’s expected types without modifying its source code.

内容的提问来源于stack exchange，提问作者bricoldur