geopandas.GeoSeries.union

GeoSeries.union(other, align=True)

Returns a GeoSeries of the union of points in each aligned geometry with other.

The operation works on a 1-to-1 row-wise manner:

Parameters

otherGeoseries or geometric object

The Geoseries (elementwise) or geometric object to find the union with.

alignbool (default True)

If True, automatically aligns GeoSeries based on their indices. If False, the order of elements is preserved.

Returns

GeoSeries

See also

GeoSeries.symmetric_difference

GeoSeries.difference

GeoSeries.intersection

Examples

>>> from shapely.geometry import Polygon, LineString, Point
>>> s = geopandas.GeoSeries(
...     [
...         Polygon([(0, 0), (2, 2), (0, 2)]),
...         Polygon([(0, 0), (2, 2), (0, 2)]),
...         LineString([(0, 0), (2, 2)]),
...         LineString([(2, 0), (0, 2)]),
...         Point(0, 1),
...     ],
... )
>>> s2 = geopandas.GeoSeries(
...     [
...         Polygon([(0, 0), (1, 1), (0, 1)]),
...         LineString([(1, 0), (1, 3)]),
...         LineString([(2, 0), (0, 2)]),
...         Point(1, 1),
...         Point(0, 1),
...     ],
...     index=range(1, 6),
... )

>>> s
0    POLYGON ((0.00000 0.00000, 2.00000 2.00000, 0....
1    POLYGON ((0.00000 0.00000, 2.00000 2.00000, 0....
2        LINESTRING (0.00000 0.00000, 2.00000 2.00000)
3        LINESTRING (2.00000 0.00000, 0.00000 2.00000)
4                              POINT (0.00000 1.00000)
dtype: geometry

>>> s2
1    POLYGON ((0.00000 0.00000, 1.00000 1.00000, 0....
2        LINESTRING (1.00000 0.00000, 1.00000 3.00000)
3        LINESTRING (2.00000 0.00000, 0.00000 2.00000)
4                              POINT (1.00000 1.00000)
5                              POINT (0.00000 1.00000)
dtype: geometry

We can do union of each geometry and a single shapely geometry:

>>> s.union(Polygon([(0, 0), (1, 1), (0, 1)]))
0    POLYGON ((0.00000 0.00000, 0.00000 1.00000, 0....
1    POLYGON ((0.00000 0.00000, 0.00000 1.00000, 0....
2    GEOMETRYCOLLECTION (POLYGON ((0.00000 0.00000,...
3    GEOMETRYCOLLECTION (POLYGON ((0.00000 0.00000,...
4    POLYGON ((0.00000 1.00000, 1.00000 1.00000, 0....
dtype: geometry

We can also check two GeoSeries against each other, row by row. The GeoSeries above have different indices. We can either align both GeoSeries based on index values and compare elements with the same index using align=True or ignore index and compare elements based on their matching order using align=False:

>>> s.union(s2, align=True)
0                                                 None
1    POLYGON ((0.00000 0.00000, 0.00000 1.00000, 0....
2    MULTILINESTRING ((0.00000 0.00000, 1.00000 1.0...
3        LINESTRING (2.00000 0.00000, 0.00000 2.00000)
4        MULTIPOINT (0.00000 1.00000, 1.00000 1.00000)
5                                                 None
dtype: geometry

>>> s.union(s2, align=False)
0    POLYGON ((0.00000 0.00000, 0.00000 1.00000, 0....
1    GEOMETRYCOLLECTION (POLYGON ((0.00000 0.00000,...
2    MULTILINESTRING ((0.00000 0.00000, 1.00000 1.0...
3        LINESTRING (2.00000 0.00000, 0.00000 2.00000)
4                              POINT (0.00000 1.00000)
dtype: geometry

geopandas.GeoSeries.symmetric_difference geopandas.GeoSeries.buffer