geopandas.GeoSeries.union_all#

GeoSeries.union_all(method='unary')[source]#

Returns a geometry containing the union of all geometries in the GeoSeries.

By default, the unary union algorithm is used. If the geometries are non-overlapping (forming a coverage), GeoPandas can use a significantly faster algorithm to perform the union using the method="coverage" option.

Parameters:

methodstr (default "unary")

The method to use for the union. Options are:

"unary": use the unary union algorithm. This option is the most robust but can be slow for large numbers of geometries (default).
"coverage": use the coverage union algorithm. This option is optimized for non-overlapping polygons and can be significantly faster than the unary union algorithm. However, it can produce invalid geometries if the polygons overlap.

Examples

>>> from shapely.geometry import box
>>> s = geopandas.GeoSeries([box(0, 0, 1, 1), box(0, 0, 2, 2)])
>>> s
0    POLYGON ((1 0, 1 1, 0 1, 0 0, 1 0))
1    POLYGON ((2 0, 2 2, 0 2, 0 0, 2 0))
dtype: geometry

>>> s.union_all()
<POLYGON ((0 1, 0 2, 2 2, 2 0, 1 0, 0 0, 0 1))>