GeoPandas cut lines with polygon

Question

I wanted to clip lines with polygon geometry:

from shapely.geometry import Polygon, LineString
import geopandas as gpd

polygon = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])
line1 = LineString([(0.5, 0.5), (2, 2)])
line2 = LineString([(0.9, 0.9), (2, 0.6)])


poly_gdf = gpd.GeoDataFrame(geometry=[polygon])
line_gdf = gpd.GeoDataFrame(geometry=[line1, line2])

fig, ax = plt.subplots()
poly_gdf.plot(ax=ax, alpha=0.5)
line_gdf.plot(ax=ax, color='green')

When I do it with:

gpd.overlay(line_gdf, poly_gdf, how='difference')

The result is:

TypeError: overlay only takes GeoDataFrames with (multi)polygon  geometries.

Answer 1

Reference documentation of geopandas.overlay and error message are clear:

TypeError: overlay only takes GeoDataFrames with (multi)polygon  geometries

So, I modified your code for including a second polygon:

from shapely.geometry import Polygon, LineString
import geopandas as gpd
from matplotlib import pyplot as plt

polygon1 = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])
polygon2 = Polygon([(0.5, 0.5), (1.5, 0.5), (1, 1), (0, 1), (0.5, 0.5)])
line1 = LineString([(0.5, 0.5), (2, 2)])
line2 = LineString([(0.9, 0.9), (2, 0.6)])

poly_gdf1 = gpd.GeoDataFrame(geometry=[polygon1])
poly_gdf2 = gpd.GeoDataFrame(geometry=[polygon2])
line_gdf = gpd.GeoDataFrame(geometry=[line1, line2])

overlay = gpd.overlay(poly_gdf1, poly_gdf2, how='difference')

plt.ion()

fig, ax = plt.subplots()
poly_gdf1.plot(ax=ax, alpha=0.5)
poly_gdf2.plot(ax=ax, alpha=0.5)
overlay.plot(ax=ax, color='red', alpha=0.5)
line_gdf.plot(ax=ax, color='green')

and result (red area) of overlay with two polygons is produced without any error:

On the other hand, if you want to clip lines with polygon geometry you can use intersection or difference as in following script:

from shapely.geometry import Polygon, LineString
import geopandas as gpd
from matplotlib import pyplot as plt

polygon1 = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])

line1 = LineString([(0.5, 0.5), (2, 2)])
line2 = LineString([(0.9, 0.9), (2, 0.6)])

poly_gdf1 = gpd.GeoDataFrame(geometry=[polygon1])
line_gdf = gpd.GeoDataFrame(geometry=[line1])

plt.ion()

fig, ax = plt.subplots()
poly_gdf1.plot(ax=ax, alpha=0.1)

difference = line_gdf.difference(poly_gdf1)
intersection = line_gdf.intersection(poly_gdf1)

difference.plot(ax=ax, alpha=0.5, color='magenta')
intersection.plot(ax=ax, alpha=0.5, color='green')

Result is presented in following image:

Answer 2

Wonderfull Xunilk, now a variation for all lines:

from shapely.geometry import Polygon, LineString
import geopandas as gpd
from matplotlib import pyplot as plt

polygon = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])
line1 = LineString([(0.5, 0.5), (2, 2)])
line2 = LineString([(0.9, 0.9), (2, 0.6)])


poly_gdf = gpd.GeoDataFrame(geometry=[polygon])
line_gdf = gpd.GeoDataFrame(geometry=[line1, line2])
lineas_geo=gpd.GeoDataFrame(geometry=[line_gdf.unary_union])

fig, ax = plt.subplots()
poly_gdf.plot(ax=ax, alpha=0.5)
line_gdf.plot(ax=ax, color='green')

difference = line_gdf.difference(poly_gdf)
intersection = line_gdf.intersection(poly_gdf)

difference.plot(ax=ax, alpha=0.5, color='magenta')
intersection.plot(ax=ax, alpha=0.5, color='red')

lineas_geo.intersection(poly_gdf).plot(ax=ax, alpha=1, ls='--',color='pink',lw=5)

Answer 3

The original error appears resolved in geopandas 0.13.0.

Here's the complete example code for anyone who stumbles on this like I did, looking to split lines to polygon(s).

from shapely.geometry import Polygon, LineString
import geopandas as gpd
from matplotlib import pyplot as plt

# setup mock data
polygon = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])
line1 = LineString([(0.5, 0.5), (2, 2)])
line2 = LineString([(0.9, 0.9), (2, 0.6)])

poly_gdf = gpd.GeoDataFrame(geometry=[polygon])
line_gdf = gpd.GeoDataFrame(geometry=[line1, line2])

# clip lines at polygon instersections
overlay_results = line_gdf.overlay(poly_gdf1, "union")
# note, change the operator from "union" if you only want difference or intersection.
# "union" will "split" but does not "clip"

# show results
print("original")
fig, ax = plt.subplots()
poly_gdf.plot(ax=ax, alpha=0.5)
line_gdf.plot(ax=ax, color='green')
plt.show();

print("after overlay")
fig, ax = plt.subplots()
overlay_results.plot(ax=ax, column="geometry")
poly_gdf1.plot(ax=ax, alpha=0.5)
plt.show();

print(overlay)